Highly-Efficient-Saturated-PA-Design-Using-MWO
专业英语
questions
How
do you distinguish steel from cast iron? How do you distinguish low alloy steel from high alloy steel?
1.1.1 Iron and Steel
The earth contains a large number of metals which are useful to man. One of the most important of these is iron. Modern industry needs considerable quantities of this metal, either in the form of iron or in the form of steel.
Mechanical Engineering materials
Organic polymer materials Inorganic non-metallic materials
plastic rubber Synthetic Fibers Traditional ceramics Special Ceramics Metal Matrix Composites
1.1.1 Iron and Steel
The ore becomes molten, and its oxides combine with carbon from the coke. The non-metallic constituents of the ore combine with the limestone to form a liquid slag. This floats on top of the molten iron, and passed out of the furnace through a tap. The metal which remains is pig iron.
206 EATON - EMERGENCY LIGHTING CPS全球目录2020版7指南 Led
7GuideLed SL 13011.1, 13021.1 CG-SSafety Luminaires for Escape Route Lighting* D egree of protection of the luminaire: IP41Degree of protection of module enclosure: IP20GuideLed SL 13011.1, 13021.1 CG-S• Safety luminaire with LED technology for recessed mounting• Unobtrusive. discrete appearance with round design and low installation depth of only 40 mm• Conversion to square design with optional bezel to fit to the ceiling plan if necessary• Special LED optics ensure especially efficient escape route illuminationor uniform anti-panic illumination• High Spacing by exact light direction and highly-efficient HighPowerLEDs• Up to 27 m from luminaire to luminaire with optics for escape route illumination• Up to 12 m from luminaire to luminaire with optics for antipanic illumination• Minimum service requirement due to high service life of the LEDs (up to 50.000 hours)Luminous flux ΦN Asymmetric optics 250 lmSymmetric optics 250 lmLuminous flux ΦE/ΦNat end of rated operating timer 100%Housing material PC. aluminiumHousing colour White RAL 9016Weight0.25 kgType of mounting Recessed mountingTerminals Clamp terminal 2 x 3 x 2.5 mm²Connection voltage220 – 240 V AC. 50/60 Hz176 – 275 V DCCurrent consumption - battery operation (220 V)20 mAPower consumption mains operation(apparent power/effective power)8.0 VA / 3.9 WInrush current1.5 APermissible ambient temperature-20°C to +40°CLight source HighPower LED 1 x 2 WOrdering detailsT ype Scope of supply Order No.GuideLed SL 13011.1 CG-S GuideLed SL 13011.1 CG-S. recessed mounting withasymmetric optics for escape route illumination. LEDsupply and CG-S technology (20 addresses) inhousing* with strain relief40071354480GuideLed SL 13021.1 CG-S GuideLed SL 13021.1 CG-S. recessed mounting with40071354481 GuideLed SL 13011.1 CG-SGuideLed SL 13021.1 CG-SLight distribution curveGuideLed SL 13011.1 CG-S recessedwith asymmetric opticsLight distribution curveGuideLed SL 13021.1 CG-S recessedwith symmetric opticsOrientation ofescape routeModule housing*Dimensions in mm7GuideLed SL 13011.1, 13021.1, 13012.1, 13022.1 CG-SSafety Luminaires for Escape Route LightingPlanning assistance for GuideLed SL CG-S with asymmetric optics for E = 1.0 lx (0.5 lx)Measuring height 0.02 m. maintenance factor MF = 80 %. battery operation3.0Escape route 2.3 (3.2) 6.4 (9.2) 7.3 ( 8.1)16.1 (17.8)3.5centre 2.3 (3.2) 6.5 (9.7) 8.1 ( 9.0)17.9 (19.9)4.0 2.3 (3.3) 6.5 (9.4) 8.8 ( 9.9)19.7 (21.9)4.5 2.3 (3.3) 6.6 (9.1) 9.5 (10.7)21.4 (23.7)5.0 2.2 (3.3)6.6 (9.2)10.0 (11.5)23.0 (25.6)5.5 2.1 (3.3)6.6 (9.2)10.4 (12.2)24.4 (27.4)6.0 2.0 (3.3) 6.5 (9.3)10.7 (12.9)25.8 (29.1)6.51.9 (3.2) 6.4 (9.4)7.9 (13.5)27.0 (30.8)7.01.8 (3.1) 6.2 (9.4) 7.6 (14.0)26.0 (32.3)7.5 1.7 (3.1) 6.1 (9.3) 7.3 (14.5)25.9 (33.7)8.01.6 (2.9) 5.8 (9.3) 7.0 (14.8)26.2 (35.2)8.51.4 (2.8) 5.7 (9.3) 6.7 (15.1)26.4 (36.6)9.01.2 (2.8) 5.5 (9.1) 6.1 (14.9)26.1 (37.8)9.51.0 (2.7) 5.3 (9.0) 4.7 (10.9)21.9 (37.6)10.00.6 (2.5) 5.0 (8.8) 2.5 (10.7)21.4 (36.7)Planning assistance for GuideLed SL CG-S with symmetric optics for E = 1.0 lx (0.5 lx)Measuring height 0.02 m. maintenance factor MF = 80 %. battery operation4.5 2.9 (6.6)13.0 (16.4) 3.2 (6.6)12.7 (16.4)5.0 2.4 (6.2)12.3 (17.4) 2.4 (6.4)12.4 (17.4)5.51.9 (5.3)10.6 (17.5)1.8 (5.5)11.0 (17.6)6.00.7 (4.7) 9.4 (17.8)0.9 (4.8) 9.6 (17.9)2.5Ceiling mounting 4.1 (4.6) 9.6 (10.3) 4.3 (4.7) 9.6 (10.3)3.0Room illumination4.5 (5.2)11.1 (12.0) 4.6 (5.2)11.0 (11.9)3.54.8 (5.6)12.1 (13.6) 5.1 (5.8)12.2 (13.5)4.0 3.2 (5.9)12.1 (15.0) 3.1 (6.3)12.3 (15.0)4.5 2.7 (6.2)12.6 (16.3) 2.6 (6.5)12.5 (16.3)5.0 2.5 (6.5)12.1 (17.2) 2.5 (6.8)12.4 (17.4)5.50.7 (4.3)11.6 (17.2)0.6 (4.5)11.7 (17.6)6.00.6 (3.5)11.9 (17.4)0.5 (3.7)11.8 (17.5)6.50.6 (2.8)12.0 (17.8)0.5 (1.1)11.9 (18.0)7.00.6 (3.1)11.7 (17.3)0.6 (0.7)11.8 (17.7)7.50.5 (3.5)11.3 (16.6)0.6 (0.6)11.4 (16.6)8.00.5 (0.8)10.9 (16.6)0.6 (0.5)10.9 (16.6)8.51.0 (1.0) 9.3 (16.7)1.0 (0.5) 9.3 (16.8)9.00.9 (1.2) 8.3 (16.9)1.0 (0.5) 8.3 (16.9)9.50.6 (1.5) 7.0 (16.9)0.6 (0.5) 7.1 (16.8)10.00.6 (1.5) 5.8 (16.6)0.6 (0.5) 5.8 (16.6) Escape route illuminationwith asymmetric opticsEscape route illuminationwith symmetric opticsRoom illuminationwith symmetric optics。
HIGHLY-POROUS CERAMIC CONDUCTORS AND METHOD OF MAK
专利名称：HIGHLY-POROUS CERAMIC CONDUCTORS AND METHOD OF MAKING THEM发明人：HENRI CARBONNEL,LUDOVIC HAMON申请号：AU5030172申请日：19721220公开号：AU5030172A公开日：19740620专利内容由知识产权出版社提供摘要：1414178 Sintered borides and silicides GROUPEMENT POUR LES ACTIVITES ATOMIQUES ET AVANLEES 21 Dec 1972 [22 Dec 1971] 59258/72 Heading C7D A sintered porous body is made from a mixture of (1) a fine non-sintered diboride powder of a Group IVA, VA or VIA metal with e.g. 20-80 per cent weight of a crushed diboride powder of a Group IVA, VA or VIA metal which has been hot pressed e.g. at 1000-2000‹C and (2) 1-6 per cent weight of a fluoride of a group 1A or 1B metal. The mixture is inbrated in a diee.g. graphite and sintered for at least 1 hour at 1000- 1500‹C in an inert gas such as argon. Up to 25% of a disilicide of a Group IVA, VA or VIA metal may be added to the diboride powder before hot pressing non-sintered disilicide powder may be added to the non-sintered diboride and the fluoride flux used is preferably Li F. The sintered body may be used in liquid metal pumps, electrodes for electrolysis and for resistance heating elements.申请人：HENRI CARBONNEL,LUDOVIC HAMON更多信息请下载全文后查看。
211050371_正负压一体式无空气X_射线光电子能谱原位转移仓的开发及研制
第 29 卷第 1 期分析测试技术与仪器Volume 29 Number 1 2023年3月ANALYSIS AND TESTING TECHNOLOGY AND INSTRUMENTS Mar. 2023大型仪器功能开发(30 ~ 36)正负压一体式无空气X射线光电子能谱原位转移仓的开发及研制章小余，赵志娟，袁 震，刘 芬（中国科学院化学研究所，北京 100190）摘要：针对空气敏感材料的表面分析，为了获得更加真实的表面组成与结构信息，需要提供一个可以保护样品从制备完成到分析表征过程中不接触大气环境的装置. 通过使用O圈密封和单向密封柱，提出一种简便且有效的设计概念，自主研制了正负压一体式无空气X射线光电子能谱（XPS）原位转移仓，用于空气敏感材料的XPS测试，利用单向密封柱实现不同工作需求下正负压两种模式的任意切换. 通过对空气敏感的金属Li片和CuCl粉末进行XPS分析表明，采用XPS原位转移仓正压和负压模式均可有效避免样品表面接触空气，保证测试结果准确可靠，而且采用正压密封方式转移样品可以提供更长的密封时效性. 研制的原位转移仓具有设计小巧、操作简便、成本低、密封效果好的特点，适合给有需求的用户开放使用.关键词：空气敏感；X射线光电子能谱；原位转移；正负压一体式中图分类号：O657; O641; TH842 文献标志码：B 文章编号：1006-3757（2023）01-0030-07 DOI：10.16495/j.1006-3757.2023.01.005Development and Research of Inert-Gas/Vacuum Sealing Air-Free In-Situ Transfer Module of X-Ray Photoelectron SpectroscopyZHANG Xiaoyu， ZHAO Zhijuan， YUAN Zhen， LIU Fen（Institute of Chemistry Chinese Academy of Sciences, Beijing 100190, China）Abstract：For the surface analysis of air sensitive materials, and from the sample preparation to characterization, it is necessary to provide a device that can protect samples from exposing to the atmosphere environment so as to obtain accurate and impactful data of the surface chemistry. Through the use of O-ring and one-way sealing, a simple and effective design concept has been demonstrated, and an inert-gas/vacuum sealing air-free X-ray photoelectron spectroscopic (XPS) in-situ transfer module has been developed to realize the XPS analysis of air sensitive materials. The design of one-way sealing was achieved conveniently by switching between inert-gas and vacuum sealing modes in face of different working requirements. The XPS analysis of air-sensitive metal Li sheets and CuCl powders showed that both the sealing modes (an inert-gas/vacuum sealing) of the XPS in-situ transfer module can effectively avoid air contact on the sample surface, and consequently, can ensure the accuracy and reliability of XPS data. Furthmore, the inert gas sealing mode can keep the sample air-free for a longer time. The homemade XPS in-situ transfer module in this work is characterized by a compact design, convenient operation, low cost and effective sealing, which is suitable for the open access to the users who need it.收稿日期：2022−12−07； 修订日期：2023−01−17.基金项目：中国科学院化学研究所仪器孵化项目[Instrument and Device Functional Developing Project of Institute of Chemistry Chinese Academy of Sciences]作者简介：章小余（1986−），女，硕士，工程师，主要研究方向为电子能谱技术及材料表面分析，E-mail：xyiuzhang@ .Key words：air-sensitive；X-ray photoelectron spectroscopy；in-situ transfer；inert-gas/vacuum sealingX射线光电子能谱（XPS）是一种表面灵敏的分析技术，通常用于固体材料表面元素组成和化学态分析[1]. 作为表面分析领域中最有效的方法之一，XPS广泛应用于纳米科学、微电子学、吸附与催化、环境科学、半导体、冶金和材料科学、能源电池及生物医学等诸多领域[2-3]. 其中在催化和能源电池材料分析中，有一些样品比较特殊，比如碱金属电池[4-6]、负载型纳米金属催化剂[7-8]和钙钛矿材料[9]对空气非常敏感，其表面形态和化学组成接触空气后会迅速发生改变，直接影响采集数据的准确性和有效性，因此这类样品的表面分析测试具有一定难度. 目前，常规的光电子能谱仪制样转移过程通常是在大气环境中，将样品固定在标准样品台上，随后放入仪器进样室内抽真空至1×10−6 Pa，再转入分析室内进行测试. 这种制备和进样方式无法避免样品接触大气环境，对于空气敏感材料，其表面很容易与水、氧发生化学反应，导致无法获得材料表面真实的结构信息.为了保证样品表面状态在转移至能谱仪内的过程中不受大气环境影响，研究人员采用了各种技术来保持样品转移过程中隔绝空气. 比如前处理及反应装置与电子能谱仪腔室间真空传输[10-12]、外接手套箱 [13-14]、商用转移仓[15-16]、真空蒸镀惰性金属比如Al层（1.5~6 nm）[17]等. 尽管上述技术手段有效，但也存在一些缺点，例如配套装置体积巨大、试验过程不易操作、投入成本高等，这都不利于在普通实验室内广泛应用. 而一些电子能谱仪器制造商根据自身仪器的特点也研发出了相应配套的商用真空传递仓，例如Thermofisher公司研发的一种XPS 真空转移仓，转移过程中样品处于微正压密封状态，但其价格昂贵，体积较大，转移过程必须通过手套箱大过渡舱辅助，导致传递效率低，单次需消耗至少10 L高纯氩气，因此购置使用者较少，利用率低.另外有一些国内公司也研发了类似的商品化气体保护原位传递仓，采用微正压方式密封转移样品，但需要在能谱仪器进样室舱门的法兰上外接磁耦合机械旋转推拉杆，其操作复杂且放置样品的有效区域小，单次仅可放置尺寸为3 mm×3 mm的样品3～4个，进样和测试效率较低. 因此，从2016年起本实验团队开始自主研制XPS原位样品转移装置[18]，经过结构与性能的迭代优化[19]，最终研制出一种正负压一体式无空气XPS原位转移仓[20]（本文简称XPS原位转移仓），具有结构小巧、操作便捷、成本低、密封效果好、正压和负压密封两种模式转移样品的特点. 为验证装置的密封时效性能，本工作选取两种典型的空气敏感材料进行测试，一种是金属Li材料，其化学性质非常活泼，遇空气后表面迅速与空气中的O2、N2、S等反应导致表面化学状态改变. 另一种是无水CuCl粉末，其在空气中放置短时间内易发生水解和氧化. 试验结果表明，该XPS 原位转移仓对不同类型的空气敏感样品的无空气转移均可以提供更便捷有效的密封保护. 目前，XPS原位转移仓已在多个科研单位的实验室推广使用，支撑应用涉及吸附与催化、能源环境等研究领域.1 试验部分1.1 XPS原位转移仓的研制基于本实验室ESCALAB 250Xi型多功能光电子能谱仪器（Thermofisher 公司）的特点，研究人员设计了XPS原位转移仓. 为兼顾各个部件强度、精度与轻量化的要求，所有部件均采用钛合金材料.该装置从整体结构上分为样品台、密封罩和紧固挡板三个部件，如图1（a）~（c）所示. 在密封罩内部通过单向密封设计[图1（e）]使得XPS原位转移仓实现正负压一体，实际操作中可通过调节密封罩上的螺帽完成两种模式任意切换. 同时，从图1（e）中可以直观看到，密封罩与样品台之间通过O圈密封，利用带有螺钉的紧固挡板将二者紧密固定. 此外，为确保样品台与密封罩对接方位正确，本设计使用定向槽定位样品台与密封罩位置，保证XPS原位转移仓顺利传接到仪器进样室.XPS原位转移仓使用的具体流程：在手套箱中将空气敏感样品粘贴至样品台上，利用紧固挡板使样品台和密封罩固定在一起，通过调节密封罩上的螺帽将样品所在区域密封为正压惰性气氛（压强为300 Pa、环境气氛与手套箱内相同）或者负压真空状态，其整体装配实物图如图1（d）所示. 该转移仓结构小巧，整体尺寸仅52 mm×58 mm×60 mm，可直接放入手套箱小过渡舱传递. 由于转移仓尺寸小，其第 1 期章小余，等：正负压一体式无空气X射线光电子能谱原位转移仓的开发及研制31原料成本大大缩减，整体造价不高. 转移仓送至能谱仪进样室后，配合样品停放台与进样杆的同时双向对接，将转移仓整体固定在进样室内，如图1（f ）所示. 此时关闭进样室舱门开始抽真空，当样品台与密封罩内外压强平衡后密封罩自动解除真空密封，但仍然处于O 圈密闭状态. 等待进样室真空抽至1×10−4Pa 后，使用能谱仪进样室的样品停放台摘除脱离的密封罩[如图1（g ）所示]，待真空抽至1×10−6Pa ，即可将样品送入分析室进行XPS 测试.整个试验过程操作便捷，实现了样品从手套箱转移至能谱仪内不接触大气环境.1.2 试验过程1.2.1 样品准备及转移试验所用手套箱是布劳恩惰性气体系统（上海）有限公司生产，型号为MB200MOD （1500/780）NAC ；金属Li 片购自中能锂业，纯度99.9%；CuCl 购自ALFA 公司，纯度99.999%.金属Li 片的制备及转移：将XPS 原位转移仓整体通过手套箱过渡舱送入手套箱中，剪取金属Li 片用双面胶带固定于样品台上，分别采用正压、负压两种密封模式将XPS 原位转移仓整体从手套箱中取出，分别在空气中放置0、2、4、8、18、24、48、72 h 后送入能谱仪内，进行XPS 测试.CuCl 粉末的制备及转移：在手套箱中将CuCl 粉末压片[21]，使用上述同样的制备方法，将XPS 原位转移仓整体在空气中分别放置0、7、24、72 h 后送入能谱仪内，进行XPS 测试.1.2.2 样品转移方式介绍样品在手套箱中粘贴完成后，分别采用三种方式将其送入能谱仪. 第一种方式是在手套箱内使用标准样品台粘贴样品，将其装入自封袋密封，待能谱仪进样室舱门打开后，即刻打开封口袋送入仪器中开始抽真空等待测试，整个转移过程中样品暴露空气约15 s. 第二种方式是使用XPS 原位转移仓负压密封模式转移样品，具体操作步骤：利用紧固挡板将样品台和密封罩固定在一起，逆时针（OPEN ）旋动螺帽至顶部，放入手套箱过渡舱并将其抽为真空，此过程中样品所在区域也抽至负压. 取出整体装置后再顺时针（CLOSE ）旋动螺帽至底部，将样品所在区域进一步锁死密封. 样品在负压环境中转移至XPS 实验室，拆卸掉紧固挡板，随即送入能谱仪进样室内. 第三种方式是使用XPS 原位转移仓正压密封模式转移样品，具体操作步骤：利用紧固挡板将样品台和密封罩固定在一起，顺时针（CLOSE ）旋螺帽抽气管限位板单向密封柱密封罩主体O 圈样品台紧固挡板(e) 密封罩对接停放台机械手样品台对接进样杆(a)(b)(c)(d)(g)图1 正负压一体式无空气XPS 原位转移仓系统装置（a ）样品台，（b ）密封罩，（c ）紧固挡板，（d ）整体装配实物图，（e ）整体装置分解示意图，（f ）样品台与密封罩在进样室内对接完成，（g ）样品台与密封罩在进样室内分离Fig. 1 System device of inert-gas/vacuum sealing air-free XPS in-situ transfer module32分析测试技术与仪器第 29 卷动螺帽至底部，此时样品所在区域密封为正压惰性气氛. 直至样品转移至XPS 实验室，再使用配套真空抽气系统（如图2所示），通过抽气管将样品所在区域迅速抽为负压，拆卸掉紧固挡板，随即送入能谱仪进样室内.图2 能谱仪实验室内配套真空抽气系统Fig. 2 Vacuum pumping system in XPSlaboratory1.2.3 XPS 分析测试试验所用仪器为Thermo Fisher Scientific 公司的ESCALAB 250Xi 型多功能X 射线光电子能谱仪，仪器分析室基础真空为1×10−7Pa ，X 射线激发源为单色化Al 靶（Alk α，1 486.6 eV ），功率150 W ，高分辨谱图在30 eV 的通能及0.05 eV 的步长等测试条件下获得，并以烃类碳C 1s 为284.8 eV 的结合能为能量标准进行荷电校正.2 结果与讨论2.1 测试结果分析为了验证XPS 原位转移仓的密封性能，本文做了一系列的对照试验，选取空气敏感的金属Li 片和CuCl 粉末样品进行XPS 测试，分别采用上述三种方式转移样品，并考察了XPS 原位转移仓密封状态下在空气中放置不同时间后对样品测试结果的影响.2.1.1 负压密封模式下XPS 原位转移仓对金属Li片的密封时效性验证将金属Li 片通过两种（标准和负压密封）方式转移并在空气中放置不同时间，对这一系列样品进行XPS 测试，Li 1s 和C 1s 高分辨谱图结果如图3（a ）（b ）所示，试验所测得的Li 1s 半峰宽值如表1所列. 根据XPS 结果分析，金属Li 片采用标准样品台进样（封口袋密封），短暂暴露空气约15 s ，此时Li 1s 的半峰宽为1.62 eV. 而采用XPS 原位转移仓负压密封模式转移样品时，装置整体放置空气18 h 内，Li 1s 的半峰宽基本保持为（1.35±0.03） eV. 放置空气24 h 后，Li 1s 的半峰宽增加到与暴露空气15 s 的金属Li 片一样，说明此时原位转移仓的密封性能衰减，金属Li 片与渗入内部的空气发生反应生成新物质导致Li 1s 半峰宽变宽. 由图3（b ）中C 1s 高分辨谱图分析，结合能位于284.82 eV 的峰归属为C-C/污染C ，位于286.23 eV 的峰归属为C-OH/C-O-CBinding energy/eVI n t e n s i t y /a .u .Li 1s半峰宽增大暴露 15 s密封放置 24 h 密封放置 18 h 密封放置 8 h 密封放置 4 h 密封放置 0 h6058565452Binding energy/eVI n t e n s i t y /a .u .C 1s(a)(b)暴露 1 min 暴露 15 s 密封放置 24 h 密封放置 18 h 密封放置 0 h292290288284282286280图3 金属Li 片通过两种（标准和负压密封）方式转移并在空气中放置不同时间的（a ）Li 1s 和（b ）C 1s 高分辨谱图Fig. 3 High-resolution spectra of (a) Li 1s and (b) C 1s of Li sheet samples transferred by two methods (standard andvacuum sealings) and placed in air for different times第 1 期章小余，等：正负压一体式无空气X 射线光电子能谱原位转移仓的开发及研制33键，位于288.61~289.72 eV的峰归属为HCO3−/CO32−中的C[22]. 我们从C 1s的XPS谱图可以直观的看到，与空气短暂接触后，样品表面瞬间生成新的结构，随着暴露时间增加到1 min，副反应产物大量增加（HCO3−/CO32−）. 而XPS原位转移仓负压密封模式下在空气中放置18 h内，C结构基本不变，在空气中放置24 h后，C结构只有微小变化. 因此根据试验结果分析，对于空气极其敏感的材料，在负压密封模式下，建议XPS原位转移仓在空气中放置时间不要超过18 h. 这种模式适合对空气极其敏感样品的短距离转移.表 1 通过两种（标准和负压密封）方式转移并在空气中放置不同时间的Li 1s的半峰宽Table 1 Full width at half maxima (FWHM) of Li 1stransferred by two methods (standard and vacuum sealings) and placed in air for different times样品说明进样方式半峰宽/eV密封放置0 h XPS原位转移仓负压密封模式转移1.38密封放置2 h同上 1.39密封放置4 h同上 1.36密封放置8 h同上 1.32密封放置18 h同上 1.32密封放置24 h同上 1.62暴露15 s标准样品台进样（封口袋密封）1.622.1.2 正压密封模式下原位转移仓对金属Li片的密封时效性验证将金属Li片通过两种（标准和正压密封）方式转移并在空气中放置不同时间，对这一系列样品进行XPS测试，Li 1s高分辨谱图结果如图4所示，所测得的Li 1s半峰宽值如表2所列. 根据XPS结果分析，XPS原位转移仓正压密封后，在空气中放置72 h内，Li 1s半峰宽基本保持为（1.38±0.04） eV，说明有明显的密封效果，金属Li片仍然保持原有化学状态. 所以对于空气极其敏感的材料，在正压密封模式下，可至少在72 h内保持样品表面不发生化学态变化. 这种模式适合长时间远距离（可全国范围内）转移空气敏感样品.2.1.3 负压密封模式下XPS原位转移仓对空气敏感样品CuCl的密封时效性验证除了金属Li片样品，本文还继续考察XPS原位转移仓对空气敏感样品CuCl的密封时效性. 图5为CuCl粉末通过两种（标准和负压密封）方式转移并在空气中放置不同时间的Cu 2p高分辨谱图. XPS谱图中结合能[22]位于932.32 eV的峰归属为Cu+的Cu 2p3/2，位于935.25 eV的峰归属为Cu2+的Cu 2p3/2，此外，XPS谱图中位于940.00~947.50 eV 处的峰为Cu2+的震激伴峰，这些震激伴峰被认为是表 2 通过两种（标准和正压密封）方式转移并在空气中放置不同时间的Li 1s的半峰宽Table 2 FWHM of Li 1s transferred by two methods(standard and inert gas sealings) and placed in air fordifferent times样品说明进样方式半峰宽/eV 密封放置0 h XPS原位转移仓正压密封模式转移1.42密封放置2 h同上 1.35密封放置4 h同上 1.35密封放置8 h同上 1.34密封放置18 h同上 1.38密封放置24 h同上 1.39密封放置48 h同上 1.42密封放置72 h同上 1.38暴露15 s标准样品台进样（封口袋密封）1.62Binding energy/eVIntensity/a.u.Li 1s半峰宽比正压密封的宽半峰宽=1.62 eV半峰宽=1.38 eV暴露 15 s密封放置 72 h密封放置 48 h密封放置 24 h密封放置 18 h密封放置 0 h605856545250图4 金属Li片通过两种（标准和正压密封）方式转移并在空气中放置不同时间的Li 1s高分辨谱图Fig. 4 High-resolution spectra of Li 1s on Li sheet samples transferred by two methods (standard and inert gas sealings) and placed in air for different times34分析测试技术与仪器第 29 卷价壳层电子向激发态跃迁的终态效应所产生[23]，而在Cu +和Cu 0中则观察不到.根据XPS 结果分析，CuCl 在XPS 原位转移仓保护（负压密封）下，即使放置空气中72 h ，测得的Cu 2p 高分辨能谱图显示只有Cu +存在，说明CuCl 并未被氧化. 若无XPS 原位转移仓保护，CuCl 粉末放置空气中3 min 就发生了比较明显的氧化，从测得的Cu 2p 高分辨能谱图能够直观的看到Cu 2+及其震激伴峰的存在，并且随着放置时间增加到40 min ，其氧化程度也大大增加. 因此，对于空气敏感的无机材料、纳米催化剂和钙钛矿材料等，采用负压密封模式转移就可至少在72 h 内保持样品表面不发生化学态变化.3 结论本工作中自主研制的正负压一体式无空气XPS原位转移仓在空气敏感样品转移过程中可以有效隔绝空气，从而获得样品最真实的表面化学结构.试验者可根据样品情况和实验室条件选择转移模式，并在密封有效时间内将样品从实验室转移至能谱仪中完成测试. 综上所述，该XPS 原位转移仓是一种设计小巧、操作简便、密封性能优异、成本较低的样品无水无氧转移装置，因此非常适合广泛开放给有需求的试验者使用. 在原位和准原位表征技术被广泛用于助力新材料发展的现阶段，希望该设计理念能对仪器功能的开发和更多准原位表征测试的扩展提供一些启示.参考文献：黄惠忠. 论表面分析及其在材料研究中的应用[M ].北京: 科学技术文献出版社, 2002: 16-18.［ 1 ］杨文超, 刘殿方, 高欣, 等. X 射线光电子能谱应用综述[J ]. 中国口岸科学技术，2022，4（2）：30-37.[YANG Wenchao, LIU Dianfang, GAO Xin, et al.TheapplicationofX -rayphotoelectronspectroscopy [J ]. China Port Science and Technology ，2022，4 （2）：30-37.]［ 2 ］郭沁林. X 射线光电子能谱[J ]. 物理，2007，36（5）：405-410. [GUO Qinlin. X -ray photoelectron spectro-scopy [J ]. Physics ，2007，36 （5）：405-410.]［ 3 ］Malmgren S, Ciosek K, Lindblad R, et al. Con-sequences of air exposure on the lithiated graphite SEI [J ]. Electrochimica Acta ，2013，105 ：83-91.［ 4 ］Zhang Y H, Chen S M, Chen Y, et al. Functional poly-ethylene glycol-based solid electrolytes with enhanced interfacial compatibility for room-temperature lithium metal batteries [J ]. Materials Chemistry Frontiers ，2021，5 （9）：3681-3691.［ 5 ］周逸凡, 杨慕紫, 佘峰权, 等. X 射线光电子能谱在固态锂离子电池界面研究中的应用[J ]. 物理学报，2021，70（17）：178801. [ZHOU Yifan, YANG Muzi,SHE Fengquan, et al. Application of X -ray photoelec-tron spectroscopy to study interfaces for solid-state lithium ion battery [J ]. Acta Physica Sinica ，2021，70（17）：178801.]［ 6 ］Huang J J, Song Y Y, Ma D D, et al. The effect of thesupport on the surface composition of PtCu alloy nanocatalysts: in situ XPS and HS-LEIS studies [J ].Chinese Journal of Catalysis ，2017，38 （7）：1229-1236.［ 7 ］Koley P, Shit S C, Sabri Y M, et al. Looking into moreeyes combining in situ spectroscopy in catalytic bio-fuel upgradation with composition-graded Ag-Co core-shell nanoalloys [J ]. ACS Sustainable Chemistry &Engineering ，2021，9 （10）：3750-3767.［ 8 ］Opitz A K, Nenning A, Rameshan C, et al. Enhancingelectrochemical water-splitting kinetics by polarization-driven formation of near-surface iron(0): an in situ XPS study on perovskite-type electrodes [J ]. Ange-wandte Chemie (International Ed in English)，2015，54（9）：2628-2632.［ 9 ］Czekaj I, Loviat F, Raimondi F, et al. Characterization［ 10 ］Binding energy/eVI n t e n s i t y /a .u .Cu 2pCu +Cu 2+暴露 3 min暴露 40 min 密封放置 7 h 密封放置 72 h 密封放置 24 h密封放置 0 h960950945935925955940930920图5 CuCl 粉末通过两种（标准和负压密封）方式转移并在空气中放置不同时间的Cu 2p 高分辨谱图Fig. 5 High-resolution spectra of Cu 2p on CuCl powder samples transferred by two methods (standard and vacuumsealings) and placed in air for different times第 1 期章小余，等：正负压一体式无空气X 射线光电子能谱原位转移仓的开发及研制35of surface processes at the Ni-based catalyst during the methanation of biomass-derived synthesis gas: X -ray photoelectron spectroscopy (XPS)[J ]. Applied Cata-lysis A:General ，2007，329 ：68-78.Rutkowski M M, McNicholas K M, Zeng Z Q, et al.Design of an ultrahigh vacuum transfer mechanism to interconnect an oxide molecular beam epitaxy growth chamber and an X -ray photoemission spectroscopy analysis system [J ]. Review of Scientific Instruments ，2013，84 （6）：065105.［ 11 ］伊晓东, 郭建平, 孙海珍, 等. X 射线光电子能谱仪样品前处理装置的设计及应用[J ]. 分析仪器，2008（5）：8-11. [YI Xiaodong, GUO Jianping, SUN Haizhen, et al. Design of a sample pretreatment device for X -ray photoelectron spectrometer [J ]. Analytical Instrumentation ，2008 （5）：8-11.]［ 12 ］Aurbach D, Weissman I, Schechter A, et al. X -ray pho-toelectron spectroscopy studies of lithium surfaces pre-pared in several important electrolyte solutions. A comparison with previous studies by Fourier trans-form infrared spectroscopy [J ]. Langmuir ，1996，12（16）：3991-4007.［ 13 ］Światowska-Mrowiecka J, Maurice V, Zanna S, et al.XPS study of Li ion intercalation in V 2O 5 thin films prepared by thermal oxidation of vanadium metal [J ].Electrochimica Acta ，2007，52 （18）：5644-5653.［ 14 ］Weingarth D, Foelske-Schmitz A, Wokaun A, et al. Insitu electrochemical XPS study of the Pt/[BF 4]system [J ]. Electrochemistry Communications ，2011，13 （6）：619-622.［ 15 ］Schneider J D, Agocs D B, Prieto A L. Design of asample transfer holder to enable air-free X -ray photo-electron spectroscopy [J ]. Chemistry of Materials ，2020，32 （19）：8091-8096.［ 16 ］Karamurzov B S, Kochur A G, Misakova L B, et al.Calculation of the pure surface composition of the bin-ary alloy according to XPS data obtained after the al-loy surface contact with air [J ]. Journal of Structural Chemistry ，2015，56 （3）：576-581.［ 17 ］章小余, 赵志娟. 一种半原位XPS 样品转移装置: 中国, 201620925237.5[P ]. 2017-02-15.［ 18 ］章小余, 袁震, 赵志娟. 一种半原位X 射线光电子能谱分析仪的样品转移装置: 中国, 201720056623.X [P ]. 2017-12-08.［ 19 ］袁震, 章小余, 赵志娟. 一种样品转移装置及转移方法: 中国, 2011203822.1[P ]. 2022-03-01.［ 20 ］刘芬, 赵志娟, 邱丽美, 等. XPS 分析固体粉末时的样品制备法研究[J ]. 分析测试技术与仪器，2007，13（2）：107-109. [LIU Fen, ZHAO Zhijuan, QIU Limei, et al. Study of sample preparation method for XPS analysis of powdered samples [J ]. Analysis and Testing Technology and Instruments ，2007，13 （2）：107-109.]［ 21 ］Wagner C D, Riggs W M, Davis L E, et al. Handbookof X -ray photoelectron spectroscopy [M ]. Eden Prair-ie, Minnesota, 1978.［ 22 ］Watts J F, Wolstenholme J. 表面分析(XPS 和AES)引论[M ]. 吴正龙, 译. 上海: 华东理工大学出版社,2008.［ 23 ］36分析测试技术与仪器第 29 卷。
g-C3N4
第42卷第10期2023年10月硅㊀酸㊀盐㊀通㊀报BULLETIN OF THE CHINESE CERAMIC SOCIETY Vol.42㊀No.10October,2023g-C 3N 4/Ag 基二元复合光催化剂降解环境污染物的研究进展柏林洋1,蔡照胜2(1.江苏旅游职业学院,扬州㊀225000;2.盐城工学院化学化工学院,盐城㊀224051)摘要:光催化技术在太阳能资源利用方面呈现出良好的应用前景,已受到世界各国的广泛关注㊂g-C 3N 4是一种二维结构的非金属聚合物型半导体材料,具有合成简单㊁成本低㊁化学性质稳定㊁无毒等特点,在环境修复和能量转化方面应用潜力较大㊂但g-C 3N 4存在对可见光吸收能力差㊁比表面积小和光生载流子复合速率高等缺点,限制了其实际应用㊂构筑异质结光催化剂是提高光催化效率的有效途径之一㊂基于Ag 基材料的特点,前人对g-C 3N 4/Ag 基二元复合光催化剂进行了大量研究,并取得显著成果㊂本文总结了近年来AgX(X =Cl,Br,I)/g-C 3N 4㊁Ag 3PO 4/g-C 3N 4㊁Ag 2CO 3/g-C 3N 4㊁Ag 3VO 4/g-C 3N 4㊁Ag 2CrO 4/g-C 3N 4㊁Ag 2O /g-C 3N 4和Ag 2MoO 4/g-C 3N 4复合光催化剂降解环境污染物的研究进展,并评述了g-C 3N 4/Ag 基二元复合光催化剂目前面临的主要挑战,展望了其未来发展趋势㊂关键词:g-C 3N 4;Ag 基材料;二元复合光催化剂;光催化性能;环境污染物中图分类号:TQ426㊀㊀文献标志码:A ㊀㊀文章编号:1001-1625(2023)10-3755-09Research Progress on g-C 3N 4/Ag-Based Binary Composite Photocatalysts for Degradation of Environmental PollutantsBAI Linyang 1,CAI Zhaosheng 2(1.Jiangsu Institute of Tourism,Yangzhou 225000,China;2.School of Chemistry and Chemical Engineering,Yancheng Institute of Technology,Yancheng 224051,China)Abstract :Photocatalysis technology shows a good application prospect in the utilization of solar energy resource and has attracted worldwide attention.g-C 3N 4is a two-dimensional polymeric metal-free semiconductor material with the characteristics of facile synthesis,low cost,high chemical stability and non-toxicity,which has great potential in environmental remediation and energy conversion.However,g-C 3N 4has the drawbacks of poor visible light absorption capacity,low specific surface area and high recombination rate of photogenerated charge carriers,which limits its practical application.Constructing heterojunction photocatalyst has become one of effective pathways for boosting photocatalytic efficiency.Based on the inherent merits of Ag-based materials,a lot of researches have been carried out on g-C 3N 4/Ag-based binary photocatalysts and prominent results have been achieved.Recent advances on AgX (X =Cl,Br,I)/g-C 3N 4,Ag 3PO 4/g-C 3N 4,Ag 2CO 3/g-C 3N 4,Ag 3VO 4/g-C 3N 4,Ag 2CrO 4/g-C 3N 4,Ag 2O /g-C 3N 4and Ag 2MoO 4/g-C 3N 4composite photocatalysts for the degradation of environmental pollutants were summarized.The major challenges of g-C 3N 4/Ag-based binary composite photocatalysts were reviewed and the future development trends were also forecast.Key words :g-C 3N 4;Ag-based material;binary composite photocatalyst;photocatalytic performance;environmental pollutant㊀收稿日期:2023-05-15;修订日期:2023-06-12基金项目:江苏省高等学校自然科学研究面上项目(19KJD530002)作者简介:柏林洋(1967 ),男,博士,副教授㊂主要从事光催化材料方面的研究㊂E-mail:linybai@通信作者:蔡照胜,博士,教授㊂E-mail:jsyc_czs@0㊀引㊀言随着全球经济的快速增长和工业化进程的加快,皮革㊁印染㊁制药和化工等行业排放的环境污染物总量3756㊀陶㊀瓷硅酸盐通报㊀㊀㊀㊀㊀㊀第42卷也不断增长㊂这些环境污染物存在成分复杂㊁毒性大㊁难以降解等特点,对人们的身体健康和生态环境产生严重威胁,已成为制约经济和社会发展的突出问题㊂如何实现环境污染物的高效降解是目前亟待解决的重要问题㊂效率低㊁能耗高及存在二次污染是利用传统处理方法处置环境污染物的主要缺陷[1]㊂光催化技术作为一种新型的绿色技术,具有环境友好㊁成本低㊁反应效率高和无二次污染等优点,在解决环境污染问题方面具有很大的发展潜力,深受人们的关注[2-4]㊂g-C3N4属于一种非金属聚合物型半导体材料,具有二维分子结构,即C原子和N原子通过sp2杂化形成的共轭石墨烯平面结构,具有适宜的禁带宽度(2.7eV)和对460nm以下可见光良好的响应能力㊂g-C3N4具有合成原料成本低㊁制备工艺简单㊁耐酸耐碱和稳定性好等特点,在催化[5]㊁生物[6]和材料[7]等领域应用广泛㊂然而,g-C3N4较小的比表面积㊁较弱的可见光吸收能力和较快的光生载流子复合率等不足导致其光量子利用率不高,给实际应用带来较大困难[8]㊂为了克服上述问题,前人提出了对g-C3N4进行形貌调控[9]㊁元素掺杂[10-11]和与其他半导体耦合[12-13]等方法㊂其中,将g-C3N4与其他半导体耦合形成异质结光催化剂最为常见㊂Ag基半导体材料因具有成本合理㊁光电性能好和光催化活性高等特点而深受青睐,但仍存在光生载流子快速复合和光腐蚀等缺陷㊂近年来,人们将Ag基材料与g-C3N4进行复合,整体提高了复合光催化剂的催化性能,并由此取得了大量极有价值的科研成果㊂本文综述了近年来g-C3N4/Ag银基二元复合光催化剂的制备方法㊁性能和应用等方面的研究现状,同时展望了未来的发展趋势,期望能为该领域的研究人员提供新的思路㊂1㊀g-C3N4/Ag基二元复合光催化剂近年来,基于Ag基半导体材料能与g-C3N4能带结构匹配的特点,构筑g-C3N4/Ag基异质结型复合光催化体系已成为国内外的研究热点㊂这类催化剂通常采用沉淀法在g-C3N4表面负载Ag基半导体材料㊂其中,Ag基体的成核和生长是关键问题㊂通过对Ag基材料成核和生长工艺的控制,实现了Ag基材料在g-C3N4上的均匀分布㊂此外,通过对g-C3N4微观结构进行调控,使其具有较大的比表面积和较高的结晶度,从而进一步提高复合光催化剂的催化性能㊂相对于纯g-C3N4和Ag基光催化剂,g-C3N4/Ag基二元复合光催化剂通过两组分的协同效应和界面作用,不仅能提高对可见光的吸收利用率,而且能有效抑制g-C3N4和Ag基材料中光生e-/h+对的重组,从而提高复合光催化剂的活性和稳定性㊂在g-C3N4/Ag基二元复合光催化材料中,以AgX(X=Cl,Br,I)/g-C3N4㊁Ag3PO4/g-C3N4㊁Ag2CO3/g-C3N4㊁Ag3VO4/g-C3N4㊁Ag2CrO4/g-C3N4㊁Ag2O/g-C3N4和Ag2MoO4/g-C3N4为典型代表㊂1.1㊀AgX(X=Cl,Br,I)/g-C3N4二元复合光催化剂AgX(X=Cl,Br,I)在杀菌㊁有机污染物降解和光催化水解产氢等方面展现出优异的性能㊂但AgX (X=Cl,Br,I)是一种光敏材料,在可见光下容易发生分解,形成Ag0,从而影响其催化活性及稳定性㊂将AgX(X=Cl,Br,I)与g-C3N4复合是提升AgX(X=Cl,Br,I)使用寿命㊁改善光催化性能最有效的方法之一㊂Li等[14]采用硬模板法制备出一种具有空心和多孔结构的高比表面积g-C3N4纳米球,并以其为载体,通过沉积-沉淀法得到AgBr/g-C3N4光催化材料㊂XRD分析显示AgBr的加入并没有改变g-C3N4的晶体结构,瞬态光电流试验表明AgBr/g-C3N4光电流密度高于g-C3N4,橙黄G(OG)染料经10min可见光照射后的降解率达到97%㊂Shi等[15]报道了利用沉淀回流法制备AgCl/g-C3N4光催化剂,研究了AgCl的量对催化剂结构及光催化降解草酸性能的影响,确定了最佳修饰量,分析了催化剂用量㊁草酸起始浓度㊁酸度和其他有机成分对光催化活性影响,通过自由基捕获试验揭示了光降解反应中起主要作用的活性物质为光生电子(e-)㊁羟基自由基(㊃OH)㊁超氧自由基(㊃O-2)和空穴(h+)㊂彭慧等[16]采用化学沉淀法制备具有不同含量AgI的AgI/g-C3N4光催化剂,SEM测试表明AgI纳米颗粒分布在层状结构g-C3N4薄片的表面,为催化反应提供了更多的活性位㊂该系列催化剂应用于光催化氧化降解孔雀石绿(melachite green,MG)的结果显示,AgI/g-C3N4(20%,质量分数,下同)的光催化性能最好,MG经2h可见光辐照后去除率达到99.8%㊂部分AgX(X=Cl,Br,I)/g-C3N4二元复合光催化剂的研究现状如表1所示㊂第10期柏林洋等:g-C 3N 4/Ag 基二元复合光催化剂降解环境污染物的研究进展3757㊀表1㊀AgX (X =Cl ,Br ,I )/g-C 3N 4二元复合光催化剂光降解环境污染物的研究现状Table 1㊀Research status of AgX (X =Cl ,Br ,I )/g-C 3N 4binary composite photocatalysts forphotodegradation of enviromental pollutantsPhotocatalytst Synthesis method TypePotential application Photocatalytic activity Reference AgBr /g-C 3N 4Sonication-assisted deposition-precipitation II-schemeDegradation of RhB,MB and MO 100%degradation for RhB,95%degradation for MB and 90%degradation for MO in 10min [17]AgCl /g-C 3N 4Precipitation Z-schemeDegradation of RhB and TC 96.1%degradation for RhB and 77.8%degradation for TC in 120min [18]AgCl /g-C 3N 4Solvothermal +in situ ultrasonic precipitation Z-scheme Degradation of RhB 92.2%degradation in 80min [19]AgBr /g-C 3N 4Deposition-precipitation II-schemeDegradation of MO 90%degradation in 30min [20]AgI /g-C 3N 4In-situ growth II-scheme Degradation of RhB 100%degradation in 60min [21]㊀㊀Note:MO-methyl orange,RhB-rhodamine B,TC-tetracycline hydrochloride,MB-methyl blue.1.2㊀Ag 3PO 4/g-C 3N 4二元复合光催化剂纳米Ag 3PO 4禁带宽度为2.5eV 左右,对可见光有很好的吸收作用,且光激发后具有很强的氧化性,在污染物降解和光解水制氢等领域有良好的应用前景[22]㊂但是,纳米Ag 3PO 4易团聚,光生载流子的快速重组使光催化活性大大降低,此外,Ag 3PO 4还易受光生e -的腐蚀,从而影响稳定性㊂Ag 3PO 4与g-C 3N 4复合可显著降低e -/h +对的重组,有效提高光催化性能㊂Wang 等[23]采用原位沉淀法获得Z-型异质结构g-C 3N 4/Ag 3PO 4复合光催化剂,并有效地提高了e -/h +对的分离效率㊂TEM 结果显示,Ag 3PO 4粒子被g-C 3N 4纳米片所覆盖,UV-DRS 结果表明,Ag 3PO 4的添加使g-C 3N 4吸收边发生红移,且吸收光强度显著增强,光降解实验结果显示,30%g-C 3N 4/Ag 3PO 4光催化剂在40min 内能去除约90%的RhB㊂胡俊俊等[24]利用了原位沉淀法合成了一系列Ag 3PO 4/g-C 3N 4复合光催化剂,研究了Ag 3PO 4和g-C 3N 4的物质的量比对催化剂在可见光下催化降解MB 性能的影响,发现在最优组分下,MB 经可见光辐照30min 后可以被完全降解㊂Mei 等[25]采用焙烧-沉淀法制备了一系列Ag 3PO 4/g-C 3N 4复合光催化剂,并用于可见光条件下降解双酚A(bisphenol A,BPA),发现Ag 3PO 4质量分数为25%时,光催化降解BPA 的性能最好,3h 能降解92.8%的BPA㊂潘良峰等[26]采用化学沉淀法制备出一种具有空心管状的Ag 3PO 4/g-C 3N 4光催化剂,SEM 结果表明,Ag 3PO 4颗粒均匀分布于空心管状结构g-C 3N 4的表面,两者形成一个较强异质结构,将其用于盐酸四环素(tetracycline hydrochloride,TC)光催化降解,80min 能降解98%的TC㊂Deonikar 等[27]研究了采用原位湿化学法合成催化剂过程中使用不同溶剂(去离子水㊁四氢呋喃和乙二醇)对Ag 3PO 4/g-C 3N 4的结构和光降解MB㊁RhB 及4-硝基苯酚性能的影响,发现不同溶剂对复合光催化剂的形貌有着重要影响,从而影响光催化性能,其中以四氢呋喃合成的复合光催化剂的催化降解性能最佳,这是由于g-C 3N 4纳米片均匀包裹在Ag 3PO 4的表面,从而促使两者界面形成较为密切的相互作用,有利于e -/h +对的分离㊂部分Ag 3PO 4/g-C 3N 4二元复合光催化剂的研究进展见表2㊂表2㊀Ag 3PO 4/g-C 3N 4二元复合光催化剂光降解环境污染物的研究现状Table 2㊀Research status of Ag 3PO 4/g-C 3N 4binary composite photocatalysts for photodegradation of environmental pollutantsPhotocatalyst Synthesis method Type Potential application Photocatalytic activity Reference g-C 3N 4/Ag 3PO 4In situ precipitation Z-scheme Degradation of BPA 100%degradation in 180min [28]g-C 3N 4/Ag 3PO 4Hydrothermal Z-schemeDecolorization of MB Almost 93.2%degradation in 25min [29]g-C 3N 4/Ag 3PO 4In situ prepcipitation II-scheme Reduction of Cr(VI)94.1%Cr(VI)removal efficiency in 120min [30]g-C 3N 4/Ag 3PO 4Chemical precipitation Z-scheme Degradation of RhB 90%degradation in 40min [31]g-C 3N 4/Ag 3PO 4In situ precipitation Z-scheme Degradation of levofloxacin 90.3%degradation in 30min [32]Ag 3PO 4/g-C 3N 4Chemical precipitation Z-schemeDegradation of gaseous toluene 87.52%removal in 100min [33]Ag 3PO 4/g-C 3N 4Calcination +precipitation Z-scheme Degradation of diclofenac (DCF)100%degradation in 12min [34]Ag 3PO 4/g-C 3N 4In situ deposition Z-scheme Degradation of RhB and phenol 99.4%degradation in 9min for RhB;97.3%degradation in 30min for phenol [35]3758㊀陶㊀瓷硅酸盐通报㊀㊀㊀㊀㊀㊀第42卷续表Photocatalyst Synthesis method Type Potential application Photocatalytic activity Reference Ag3PO4/g-C3N4In situ hydrothermal II-scheme Degradation of sulfapyridine(SP)94.1%degradation in120min[36] Ag3PO4/g-C3N4In situ growth Z-scheme Degradation of berberine100%degradation in15min[37] g-C3N4/Ag3PO4In situ deposition Z-scheme Degradation of ofloxacin71.9%degradation in10min[38] Ag3PO4/g-C3N4Co-precipitation Z-scheme Degradation of MO98%degradation in10min[39]g-C3N4/Ag3PO4Calcination+precipitation Z-scheme Degradation of MO,RhB and TC95%degradation for MO in30min;[40]96%degradation for RhB in15min;80%degradation for TC in30min1.3㊀Ag2CO3/g-C3N4二元复合光催化剂Ag4d轨道和O2p轨道杂化,形成Ag2CO3的价带(valence band,VB);Ag5s轨道和Ag4d轨道进行杂化,形成Ag2CO3导带(conduction band,CB),而CB中原子轨道杂化会降低Ag2CO3带隙能,从而提高光催化活性[41]㊂纳米Ag2CO3带隙能约为2.5eV,可见光响应性好,在可见光作用下表现出良好的光催化降解有机污染物特性[42-43]㊂然而,经长时间光照后,Ag2CO3晶粒中Ag+会被光生e-还原成Ag0,导致其光腐蚀,引起光催化性能下降[44]㊂Ag2CO3与g-C3N4耦合,能够有效地抑制光腐蚀,促进e-/h+对的分离,进而改善光催化性能㊂An等[45]通过构筑Z型核壳结构的Ag2CO3@g-C3N4材料来增强Ag2CO3和g-C3N4界面间的相互作用,从而有效防止光腐蚀发生,加速光生e-/h+对的分离,实现了催化剂在可见光辐照下高效降解MO㊂Yin等[46]通过水热法制备Ag2CO3/g-C3N4光催化剂,探讨了g-C3N4的含量㊁合成温度对催化剂结构和光降解草酸(oxalic acid,OA)性能的影响,获得最优条件下合成的催化剂能在45min光照时间内使OA去除率达到99.99%㊂Pan等[41]采用煅烧和化学沉淀两步法,制备了一系列Ag2CO3/g-C3N4光催化剂,TEM结果显示,Ag2CO3纳米粒子均匀分布在g-C3N4纳米片表面,且形貌规整㊁粒径均一,光催化性能测试结果表明,60% Ag2CO3/g-C3N4光催化活性最高,MO和MB分别经120和240min可见光光照后,其降解率分别为93.5%和62.8%㊂Xiu等[47]使用原位水热法构筑了Ag2CO3/g-C3N4光催化剂,光降解试验结果表明,MO经可见光辐照1h的去除率为87%㊂1.4㊀Ag3VO4/g-C3N4二元复合光催化剂纳米Ag3VO4带隙能约为2.2eV,可用于催化可见光降解环境污染物,是一种具有应用前景的新型半导体材料㊂然而,如何提高Ag3VO4光催化性能,仍然是学者研究的重点㊂构建Ag3VO4/g-C3N4异质结催化剂是提高Ag3VO4的催化性能的一种有效方法㊂该方法能够降低Ag3VO4光生载流子的复合率,拓宽可见光的吸收范围㊂Hind等[48]通过溶胶凝胶法制备出一种具有介孔结构的Ag3VO4/g-C3N4复合光催化剂,该复合催化剂经60min可见光照射能将Hg(II)全部还原,其光催化活性分别是Ag3VO4和g-C3N4的4.3倍和5.4倍,主要是由于异质结界面处各组分间紧密结合以及催化剂具有较高的比表面积和体积比,从而促进光生载流子的分离㊂蒋善庆等[49]利用化学沉淀法制备了系列Ag3VO4/g-C3N4催化剂,催化性能研究结果表明,Ag3VO4负载量为20%(质量分数)时,其光催化降解微囊藻毒素的效果最好,可见光辐照100min后降解率为85.43%,而g-C3N4在相同条件下的降解率仅为18.76%㊂1.5㊀Ag2CrO4/g-C3N4二元复合光催化剂纳米Ag2CrO4具有特殊的晶格和能带结构,其带隙能为1.8eV,可见光响应良好,是一种非常理想的可见光区半导体材料㊂然而,Ag2CrO4存在自身的电子结构和晶体的缺陷,导致其光催化效率性能较差,严重影响了实际应用[50-52]㊂将Ag2CrO4与g-C3N4复合形成异质结光催化剂是提高其光催化效率和稳定性的一种有效途径,因为Ag2CrO4在光照下产生的光生e-快速地迁移到g-C3N4表面,可避免光生e-在Ag2CrO4表面聚集而引起光腐蚀㊂Ren等[53]利用SiO2为硬模板,以氰胺为原料,合成出具有中空介孔结构的g-C3N4,再通过化学沉淀法制备了系列g-C3N4/Ag2CrO4光催化剂,并将其用于RhB和TC的可见光降解,研究发现g-C3N4/Ag2CrO4催化剂具有较高比表面积和丰富的孔道结构,在可见光辐射下表现出较高的光催化活性㊂Rajalakshmi等[54]利用水热方法合成了一系列Ag2CrO4/g-C3N4光催化剂,并将其用于对硝基苯酚的光催化降解,结果表明,Ag2CrO4质量分数为10%时,其降解率达到97%,高于单组分g-C3N4或Ag2CrO4,原因是与第10期柏林洋等:g-C 3N 4/Ag 基二元复合光催化剂降解环境污染物的研究进展3759㊀Ag 2CrO 4和g-C 3N 4界面间形成了S-型异质结,能提高e -/h +对的分离效率㊂1.6㊀Ag 2O /g-C 3N 4二元复合光催化剂纳米Ag 2O 是一种理想的可见光半导体材料,在受到光辐照后,其电子发生跃迁,CB 上光生e -能够将Ag 2O 晶粒中Ag +还原成Ag 0,而VB 上h +能够使Ag 2O 的晶格氧氧化为O 2,导致其结构不稳定㊂然而,纳米Ag 2O 在有机物污染物降解方面表现出良好的稳定性[55],这是因为Ag 2O 的表面会随着光化学反应的进行被一定数量的Ag 0纳米粒子所覆盖,而Ag 0纳米粒子作为光生e -陷阱,能够降低e -在Ag 2O 表面的富集,同时,由于光生h +具有较强的氧化性能力,既能实现对有机污染物的直接氧化,又能避免其对晶格氧的氧化,从而提高了纳米Ag 2O 光催化活性和稳定性㊂Liang 等[56]在常温下采用简易化学沉淀法制备了p-n 结Ag 2O /g-C 3N 4复合光催化剂,研究发现,起分散作用的g-C 3N 4为Ag 2O 纳米颗粒的生长提供了大量成核位点并限制了Ag 2O 纳米颗粒聚集,p-n 结的形成以及在光化学反应过程中生成的Ag 纳米粒子,加速了光生载流子的分离和迁移,拓宽了光的吸收范围,在可见光和红外光照下降解RhB 溶液过程中表现出良好的催化活性,其在可见光和红外光照下反应速率分别是g-C 3N 4的26倍和343倍㊂Jiang 等[57]通过液相法制备了一系列介孔结构的g-C 3N 4/Ag 2O 光催化剂,试验结果表明,Ag 2O 的添加显著提高了g-C 3N 4/Ag 2O 光催化剂的吸光性能和比表面积,因此对光催化性能的提升有促进作用,当Ag 2O 含量为50%时,光催化分解MB 的效果最好,经120min 可见光光照后,MB 的脱除率达到90.8%,高于g-C 3N 4和Ag 2O㊂Kadi 等[58]以Pluronic 31R 1表面活性剂为软模板,以MCM-41为硬模板,合成出具有多孔结构的Ag 2O /g-C 3N 4光催化剂,TEM 结果显示,球形Ag 2O 的纳米颗粒均匀地分布于g-C 3N 4的表面,催化性能评价表明0.9%Ag 2O /g-C 3N 4复合光催化剂光催化效果最佳,60min 能完全氧化降解环丙沙星,其降解效率分别是Ag 2O 和g-C 3N 4的4倍和10倍㊂1.7㊀Ag 2MoO 4/g-C 3N 4二元复合光催化剂Ag 2MoO 4具有良好的导电性㊁抗菌性㊁环保性,以及优良的光催化活性,在荧光材料㊁导电玻璃㊁杀菌剂和催化剂等方面有着广阔的应用前景[59]㊂但Ag 2MoO 4带隙大(3.1eV),仅能对紫外波段光进行响应,限制了其对太阳光的利用㊂当Ag 2MoO 4与g-C 3N 4进行耦合时,可以将其对太阳光的吸收范围由紫外拓展到可见光区,从而提高太阳光的利用率㊂Pandiri 等[60]通过水热合成的方法,制备出β-Ag 2MoO 4/g-C 3N 4异质结光催化剂,SEM 结果显示该催化剂中β-Ag 2MoO 4纳米颗粒均匀地分布在g-C 3N 4纳米片的表面,光催化性能测试结果表明在3h 的可见光照射下,其降解能力是β-Ag 2MoO 4和g-C 3N 4机械混合物的2.6倍,主要原因在于β-Ag 2MoO 4和g-C 3N 4两者界面间形成更为紧密的异质结,使得e -/h +对被快速分离㊂Wu 等[61]采用简单的原位沉淀方法成功构建了Ag 2MoO 4/g-C 3N 4光催化剂,并将其应用于MO㊁BPA 和阿昔洛韦的降解,结果表明该催化剂显示出良好的太阳光催化活性,这主要是因为Ag 2MoO 4和g-C 3N 4界面间存在着一定的协同效应,可有效地提高对太阳光的利用率,降低载流子的复合概率㊂2㊀g-C 3N 4/Ag 基二元复合光催化剂电荷转移机理模型研究g-C 3N 4/Ag 基二元复合光催化剂在可见光的辐照下,价带电子发生跃迁,产生e -/h +对㊂e -被催化剂表面吸附的O 2捕获产生㊃O -2,并进一步与水反应生成㊃OH,形成的三种活性自由基(h +㊁㊃O -2和㊃OH),实现水中有机污染物的高效降解(见图1)㊂而光催化反应机理与载流子的迁移机制密切相关㊂目前,g-C 3N 4/Ag 基二元复合光催化剂体系中主要存在三种不同的光生载流子的转移机制,分别为I 型㊁II 型和Z 型㊂图1㊀g-C 3N 4/Ag 基二元复合光催化剂降解有机污染物的光催化反应机理Fig.1㊀Photocatalytic reaction mechanism of g-C 3N 4/Ag-based binary composite photocatalyst for degradation of organic pollutants3760㊀陶㊀瓷硅酸盐通报㊀㊀㊀㊀㊀㊀第42卷2.1㊀I 型异质结载流子转移机理模型图2(a)为I 型异质结构中的光生e -/h +对转移示意图㊂半导体A 和半导体B 均对可见光有响应,其中,半导体A 的带隙较宽,半导体B 的带隙较窄,并且半导体B 的VB 和CB 均位于半导体A 之间,在可见光的照射下,e -发生跃迁,从CB 到VB,半导体A 的CB 上的e -和VB 上的h +分别向半导体B 的CB 和VB 转移,从而实现了e -/h +对的分离㊂以Ag 2O /g-C 3N 4复合催化剂为例[58],当Ag 2O 和g-C 3N 4相耦合时,因为g-C 3N 4的VB 具有更正的电势,h +被转移到Ag 2O 的VB 上,同时,光激发e -在g-C 3N 4的CB 上,其电势较负,e -便传输到Ag 2O 的CB 上,CB 上e -与O 2结合形成㊃O -2,并进一步与H +结合生成了㊃OH,而有机物污染物被Ag 2O 的价带上h +氧化分解生成CO 2和H 2O㊂2.2㊀II 型异质结载流子转移机理模型II 型异质结是一种能级交错带隙型结构,如图2(b)所示,其中半导体A 的CB 电位较负,在可见光照射下,e -从CB 上转移到半导体B 的CB 上,h +从半导体B 的VB 转移到半导体A 的VB 上,从而使e -/h +对得以分离㊂以Ag 3PO 4@g-C 3N 4为例[62],由于g-C 3N 4的CB 的电势较Ag 3PO 4低,光生e -从g-C 3N 4迁移到Ag 3PO 4的CB 上,而Ag 3PO 4的CB 电势较g-C 3N 4高,h +从Ag 3PO 4的VB 迁移到g-C 3N 4的VB 上,从而实现e -/h +对的分离,g-C 3N 4表面的h +可直接氧化降解MB,而Ag 3PO 4表面积聚的电子又会被氧捕获,产生H 2O 2,并进一步分解成㊃OH,从而加快MB 的降解㊂上述I 型和II 型结构CB 的氧化能力和VB 还原能力低于单一组分,造成复合半导体的氧化还原能力降低[63]㊂2.3㊀Z 型异质结载流子转移机理模型构建Z 型异质结光光催化剂使得e -和h +沿着特有的方向迁移,有效解决复合催化剂氧化还原能力降低问题[64]㊂Z 型异质结催化剂e -/h +对的迁移方向如图2(c)所示,e -从半导体B 的电势较高的CB 转移到半导体A 的电势较低的VB 进行复合,从而实现半导体A 的e -和半导体B 的h +发生分离㊂h +在半导体B 表面氧化性能更强,在半导体A 上e -具有较高还原特性,两者共同作用使环境污染物得以顺利降解㊂为了更好地解释Z 型异质结h +和e -迁移机理,以Ag 3VO 4/g-C 3N 4复合光催化剂为例[48],复合光催化剂经可见光激发后,Ag 3VO 4和g-C 3N 4都发生了e -跃迁,在Ag 3VO 4的CB 上e -与g-C 3N 4的VB 上h +进行复合时,e -对Ag 3VO 4的腐蚀作用被削弱,同时,也实现了g-C 3N 4的CB 上e -和Ag 3PO 4的价带上h +发生分离,g-C 3N 4的CB 上e -具有较强的还原性,将Hg 2+还原成Hg 0,而Ag 3PO 4的VB 上h +具有较强的氧化性,可将HOOH氧化生成CO 2和H 2O㊂图2㊀电子-空穴对转移机理示意图Fig.2㊀Schematic diagrams of electron-hole pairs transfer mechanism 3㊀结语和展望g-C 3N 4/Ag 基二元复合光催化剂因其较强的可见光响应和优异的光催化性能,在环境污染物的降解方面具有广阔的发展空间㊂近年来,国内外研究人员在理论研究㊁制备方法和光催化性能等多个领域取得了重要进展,为光催化理论的发展奠定了坚实的基础㊂然而,g-C 3N 4/Ag 基二元复合光催化剂在实际应用中还面临诸多问题,如制备工艺复杂㊁光腐蚀㊁光催化剂回收利用困难㊁光催化降解污染物的反应机理尚不明确等,第10期柏林洋等:g-C3N4/Ag基二元复合光催化剂降解环境污染物的研究进展3761㊀现有的光催化降解模型仍有较大的分歧,亟待深入研究㊂为了获得性能优良的g-C3N4/Ag基复合光催化剂,实现产业化应用,应进行以下几方面的研究:1)在g-C3N4/Ag基二元光催化剂的基础上,构建多元复合光催化剂,是进一步提升光生载流子分离效率的有效㊁可靠手段,也是当今和今后光催化剂的研究重点㊂2)对g-C3N4/Ag基二元光催化剂体系中e-/h+对的转移㊁分离和复合等过程进行系统研究,并阐明其光催化反应机制㊂3)针对当前合成的g-C3N4材料多为体相,存在着颗粒大㊁比表面积小㊁活性位少等缺陷,应通过对g-C3N4材料的形状㊁形貌及尺寸的调控,来实现Ag 基材料在g-C3N4材料表面的均匀分布,降低e-/h+对的重组概率,从而大幅度提高复合光催化剂的性能㊂4)Ag基材料的光腐蚀是导致光催化活性和稳定性下降的重要因素,探索一种更为有效的光腐蚀抑制机制,是将其推广应用的关键㊂5)当前合成的g-C3N4/Ag基二元复合光催化剂多为粉末状,存在着易团聚㊁难回收等问题,从而限制了其循环利用㊂因此,需要开展g-C3N4/Ag基二元复合光催化剂回收和再利用的研究,这将有利于社会效益和经济效益的提高㊂参考文献[1]㊀LIN Z S,DONG C C,MU W,et al.Degradation of Rhodamine B in the photocatalytic reactor containing TiO2nanotube arrays coupled withnanobubbles[J].Advanced Sensor and Energy Materials,2023,2(2):100054.[2]㊀DIAO Z H,JIN J C,ZOU M Y,et al.Simultaneous degradation of amoxicillin and norfloxacin by TiO2@nZVI composites coupling withpersulfate:synergistic effect,products and mechanism[J].Separation and Purification Technology,2021,278:119620.[3]㊀ZHAO S Y,CHEN C X,DING J,et al.One-pot hydrothermal fabrication of BiVO4/Fe3O4/rGO composite photocatalyst for the simulated solarlight-driven degradation of Rhodamine B[J].Frontiers of Environmental Science&Engineering,2021,16(3):1-16.[4]㊀JUABRUM S,CHANKHANITTHA T,NANAN S.Hydrothermally grown SDS-capped ZnO photocatalyst for degradation of RR141azo dye[J].Materials Letters,2019,245:1-5.[5]㊀SUN Z X,WANG H Q,WU Z B,et al.g-C3N4based composite photocatalysts for photocatalytic CO2reduction[J].Catalysis Today,2018,300:160-172.[6]㊀LIN L,SU Z Y,LI Y,et parative performance and mechanism of bacterial inactivation induced by metal-free modified g-C3N4undervisible light:Escherichia coli versus Staphylococcus aureus[J].Chemosphere,2021,265:129060.[7]㊀DANG X M,WU S,ZHANG H G,et al.Simultaneous heteroatom doping and microstructure construction by solid thermal melting method forenhancing photoelectrochemical property of g-C3N4electrodes[J].Separation and Purification Technology,2022,282:120005. [8]㊀VAN KHIEN N,HUU H T,THI V N N,et al.Facile construction of S-scheme SnO2/g-C3N4photocatalyst for improved photoactivity[J].Chemosphere,2022,289:133120.[9]㊀LINH P H,DO CHUNG P,VAN KHIEN N,et al.A simple approach for controlling the morphology of g-C3N4nanosheets with enhancedphotocatalytic properties[J].Diamond and Related Materials,2021,111:108214.[10]㊀XIE M,TANG J C,KONG L S,et al.Cobalt doped g-C3N4activation of peroxymonosulfate for monochlorophenols degradation[J].ChemicalEngineering Journal,2019,360:1213-1222.[11]㊀ZHEN X L,FAN C Z,TANG L,et al.Advancing charge carriers separation and transformation by nitrogen self-doped hollow nanotubes g-C3N4for enhancing photocatalytic degradation of organic pollutants[J].Chemosphere,2023,312:137145.[12]㊀AL-HAJJI L A,ISMAIL A A,FAYCAL A M,et al.Construction of mesoporous g-C3N4/TiO2nanocrystals with enhanced photonic efficiency[J].Ceramics International,2019,45(1):1265-1272.[13]㊀CUI P P,HU Y,ZHENG M M,et al.Enhancement of visible-light photocatalytic activities of BiVO4coupled with g-C3N4prepared usingdifferent precursors[J].Environmental Science and Pollution Research,2018,25(32):32466-32477.[14]㊀LI X W,CHEN D Y,LI N J,et al.AgBr-loaded hollow porous carbon nitride with ultrahigh activity as visible light photocatalysts for waterremediation[J].Applied Catalysis B:Environmental,2018,229:155-162.[15]㊀SHI H L,HE R,SUN L,et al.Band gap tuning of g-C3N4via decoration with AgCl to expedite the photocatalytic degradation and mineralizationof oxalic acid[J].Journal of Environmental Sciences,2019,84:1-12.[16]㊀彭㊀慧,刘成琪,汪楚乔,等.AgI/g-C3N4复合材料制备及其降解孔雀石绿染料性能[J].环境工程,2019,37(4):93-97.PENG H,LIU C Q,WANG C Q,et al.Preparation of AgI/g-C3N4composites and their degradation performance of malachite green dyes[J].Environmental Engineering,2019,37(4):93-97(in Chinese).[17]㊀LIANG W,TANG G,ZHANG H,et al.Core-shell structured AgBr incorporated g-C3N4nanocomposites with enhanced photocatalytic activityand stability[J].Materials Technology,2017,32(11):675-685.[18]㊀LI Y B,HU Y R,LIU Z,et al.Construction of self-activating Z-scheme g-C3N4/AgCl heterojunctions for enhanced photocatalytic property[J].Journal of Physics and Chemistry of Solids,2023,172:111055.3762㊀陶㊀瓷硅酸盐通报㊀㊀㊀㊀㊀㊀第42卷[19]㊀XIE J S,WU C Y,XU Z Z,et al.Novel AgCl/g-C3N4heterostructure nanotube:ultrasonic synthesis,characterization,and photocatalyticactivity[J].Materials Letters,2019,234:179-182.[20]㊀YANG J,ZHANG X,LONG J,et al.Synthesis and photocatalytic mechanism of visible-light-driven AgBr/g-C3N4composite[J].Journal ofMaterials Science:Materials in Electronics,2021,32:6158-6167.[21]㊀HUANG H,LI Y X,WANG H L,et al.In situ fabrication of ultrathin-g-C3N4/AgI heterojunctions with improved catalytic performance forphotodegrading rhodamine B solution[J].Applied Surface Science,2021,538:148132.[22]㊀GUO C S,CHEN M,WU L L,et al.Nanocomposites of Ag3PO4and phosphorus-doped graphitic carbon nitride for ketamine removal[J].ACSApplied Nano Materials,2019,2(5):2817-2829.[23]㊀WANG H R,LEI Z,LI L,et al.Holey g-C3N4nanosheet wrapped Ag3PO4photocatalyst and its visible-light photocatalytic performance[J].Solar Energy,2019,191:70-77.[24]㊀胡俊俊,丁同悦,陈奕桦,等.Ag3PO4/g-C3N4复合材料的制备及其光催化性能[J].精细化工,2021,38(3):483-488.HU J J,DING T Y,CHEN Y H,et al.Preparation and photocatalytic application of Ag3PO4/g-C3N4composites[J].Fine Chemicals,2021,38(3):483-488(in Chinese).[25]㊀MEI J,ZHANG D P,LI N,et al.The synthesis of Ag3PO4/g-C3N4nanocomposites and the application in the photocatalytic degradation ofbisphenol A under visible light irradiation[J].Journal of Alloys and Compounds,2018,749:715-723.[26]㊀潘良峰,阎㊀鑫,王超莉,等.中空管状g-C3N4/Ag3PO4复合催化剂的制备及其可见光催化性能[J].无机化学学报,2022,38(4):695-704.PAN L F,YAN X,WANG C L,et al.Preparation and visible light photocatalytic activity of hollow tubular g-C3N4/Ag3PO4composite catalyst[J].Chinese Journal of Inorganic Chemistry,2022,38(4):695-704(in Chinese).[27]㊀DEONIKAR V G,KOTESHWARA R K,CHUNG W J,et al.Facile synthesis of Ag3PO4/g-C3N4composites in various solvent systems withtuned morphologies and their efficient photocatalytic activity for multi-dye degradation[J].Journal of Photochemistry and Photobiology A: Chemistry,2019,368:168-181.[28]㊀DU J G,XU Z,LI H,et al.Ag3PO4/g-C3N4Z-scheme composites with enhanced visible-light-driven disinfection and organic pollutantsdegradation:uncovering the mechanism[J].Applied Surface Science,2021,541:148487.[29]㊀NAGAJYOTHI P C,SREEKANTH T V M,RAMARAGHAVULU R,et al.Photocatalytic dye degradation and hydrogen production activity ofAg3PO4/g-C3N4nanocatalyst[J].Journal of Materials Science:Materials in Electronics,2019,30(16):14890-14901.[30]㊀AN D S,ZENG H Y,XIAO G F,et al.Cr(VI)reduction over Ag3PO4/g-C3N4composite with p-n heterostructure under visible-light irradiation[J].Journal of the Taiwan Institute of Chemical Engineers,2020,117:133-143.[31]㊀YAN X,WANG Y Y,KANG B B,et al.Preparation and characterization of tubelike g-C3N4/Ag3PO4heterojunction with enhanced visible-lightphotocatalytic activity[J].Crystals,2021,11(11):1373.[32]㊀高闯闯,刘海成,孟无霜,等.Ag3PO4/g-C3N4复合光催化剂的制备及其可见光催化性能[J].环境科学,2021,42(5):2343-2352.GAO C C,LIU H C,MENG W S,et al.Preparation of Ag3PO4/g-C3N4composite photocatalysts and their visible light photocatalytic performance[J].Environmental Science,2021,42(5):2343-2352(in Chinese).[33]㊀CHENG R,WEN J Y,XIA J C,et al.Photo-catalytic oxidation of gaseous toluene by Z-scheme Ag3PO4-g-C3N4composites under visible light:removal performance and mechanisms[J].Catalysis Today,2022,388/389:26-35.[34]㊀ZHANG W,ZHOU L,SHI J,et al.Synthesis of Ag3PO4/g-C3N4composite with enhanced photocatalytic performance for the photodegradation ofdiclofenac under visible light irradiation[J].Catalysts,2018,8(2):45.[35]㊀ZHANG M X,DU H X,JI J,et al.Highly efficient Ag3PO4/g-C3N4Z-scheme photocatalyst for its enhanced photocatalytic performance indegradation of rhodamine B and phenol[J].Molecules,2021,26(7):2062.[36]㊀LI K,CHEN M M,CHEN L,et al.In-situ hydrothermal synthesis of Ag3PO4/g-C3N4nanocomposites and their photocatalytic decomposition ofsulfapyridine under visible light[J].Processes,2023,11(2):375.[37]㊀汲㊀畅,王国胜.Ag3PO4/g-C3N4异质结催化剂可见光降解黄连素[J].无机盐工业,2022,54(4):175-180.JI C,WANG G S.Degradation of berberine by visible light over Ag3PO4/g-C3N4heterojunction catalyst[J].Inorganic Chemicals Industry, 2022,54(4):175-180(in Chinese).[38]㊀CHEN R H,DING S Y,FU N,et al.Preparation of a g-C3N4/Ag3PO4composite Z-type photocatalyst and photocatalytic degradation ofOfloxacin:degradation performance,reaction mechanism,degradation pathway and toxicity evaluation[J].Journal of Environmental Chemical Engineering,2023,11(2):109440.[39]㊀HAYATI M,ABDUL H A,ZUL A M H,et al.In-depth investigation on the photostability and charge separation mechanism of Ag3PO4/g-C3N4photocatalyst towards very low visible light intensity[J].Journal of Molecular Liquids,2023,376:121494.[40]㊀DING M,ZHOU J J,YANG H C,et al.Synthesis of Z-scheme g-C3N4nanosheets/Ag3PO4photocatalysts with enhanced visible-lightphotocatalytic performance for the degradation of tetracycline and dye[J].Chinese Chemical Letters,2020,31(1):71-76.[41]㊀PAN S G,JIA B Q,FU Y S.Ag2CO3nanoparticles decorated g-C3N4as a high-efficiency catalyst for photocatalytic degradation of organiccontaminants[J].Journal of Materials Science:Materials in Electronics,2021,32(11):14464-14476.。
Nature子刊：提高高强度铝合金抗疲劳能力（翻译）
Nature子刊：提高高强度铝合金抗疲劳能力（翻译）摘要众所周知，高强度铝合金在飞机、火车、卡车和汽车的使用中抗疲劳性能表现很差，工程师们在设计铝合金制造轻量化运输结构时往往受此影响。
本文提出了一个新的概念：微观结构设计提高疲劳强度。
微结构的设计是为了利用在初始疲劳循环中传递的机械能，以动态修复微观结构中固有的弱点，使高强度铝合金的疲劳寿命提高了25倍，疲劳强度提高到拉伸强度的1/2左右（与钢相当），该方法包含了静态和动态载荷之间的差异，并代表了一种疲劳微观结构设计的概念变化。
引言铝合金是如今工程中使用量第二大合金材料，其密度仅为钢的1/3，重量较轻，无磁性，且具有优异的耐腐蚀性。
沉淀强化型铝合金由于其特定的机械性能（性能/密度），制成的部件在轻量化的应用中显示出巨大的竞争优势，例如在飞机、火车、卡车和汽车等交通行业。
正由于运输业强调轻量化以减少燃料排放，导致铝合金在这些重要应用中的使用不断增加[1、2、3]。
运输构件受交变应力的影响，因此材料必须承受的应力在本质上是循环的,这种载荷便导致疲劳[4,5,6,7,8,9]和材料抗疲劳失效的能力在这些应用中至关重要,据统计，80%的工程合金失效是由于疲劳[5,8]。
一种合金能承受较长时间（约107次循环）而不发生破坏的循环应力称为疲劳强度，它总是低于单一载荷下导致失效的拉应力。
在钢材中，疲劳强度（动态特性）和抗拉强度（静态特性）密切相关：疲劳强度/抗拉强度≈1/2（如图1）[10]，这便强调了当需要提高疲劳强度时所采取的一种方式——选择具有较高拉伸强度的材料。
然而，高强度铝合金的疲劳性能相对较差，这是铝合金的致命弱点之一。
图1显示了三种最常见的沉淀强化铝合金的疲劳和抗拉强度相关性：AA2024（Al-Cu-Mg）、AA6061（Al-Mg-Si）和AA7050（Al-Zn-Mg-（Cu））。
铝合金的疲劳强度约为其抗拉强度的1/3。
在在疲劳是必须要求性能的应用中，使用高强度铝合金时，工程师被迫围绕疲劳性能进行设计。
Co-Al2O3_高效催化CO2_氧化乙苯脱氢制苯乙烯
DOI: 10.19906/ki.JFCT.2023039Co-Al 2O 3高效催化CO 2氧化乙苯脱氢制苯乙烯司智伟1,#，丹少鹏1,#，陈树伟1,* ，潘大海1，王英雄1，闫晓亮2，李瑞丰2（1. 太原理工大学 化学学院, 山西 太原 030024；2. 太原理工大学 化学工程与技术学院, 山西 太原 030024）摘 要：采用溶胶-凝胶法制备了不同Co 含量的n Co-Al 2O 3催化剂(n = 2%、5%、10%、15%、20%)，研究了Co 含量对催化剂结构和CO 2氧化乙苯脱氢性能的影响。
结果发现，n Co-Al 2O 3催化剂上孤立的Co 2 +离子与催化活性具有良好的对应关系，表明孤立的四面体Co 2 +物种是其活性位点。
Co-Al 2O 3催化剂上的Co 物种结构和催化性能与Co 含量相关。
Co 含量较低（≤10%）时，催化剂上优先形成孤立的四面体Co 2 + 物种；随着Co 含量的增加，孤立的Co 2 +位点增加，催化剂活性随之提高。
Co 含量较高（>10%）时，催化剂上形成Co 3O 4晶体颗粒，导致孤立的Co 2 +位点减少，催化剂活性降低。
10Co-Al 2O 3表现出最佳催化性能，550 ℃下乙苯转化率达64.4%，苯乙烯选择性为99.3%，反应30 h 后，催化剂仍无明显失活，表明孤立的Co 2 +活性位点具有良好的结构稳定性和优异的抗积炭性能。
关键词：Co 基催化剂；乙苯；氧化脱氢；二氧化碳；苯乙烯中图分类号： O643.3 文献标识码： AHighly efficient Co-Al 2O 3 catalysts for oxidative dehydrogenation ofethylbenzene to styrene with CO 2SI Zhi-wei 1,#，DAN Shao-peng 1,#，CHEN Shu-wei 1,*，PAN Da-hai 1，WANG Ying-xiong 1，YAN Xiao-liang 2 ，LI Rui-feng2（1. College of Chemistry , Taiyuan University of Technology , Taiyuan 030024, China ；2. College of Chemical Engineering and Technology , Taiyuan University of Technology , Taiyuan 030024, China ）Abstract: n Co-Al 2O 3 catalysts with different Co contents (n =2%, 5%, 10%, 15%, 20%) were prepared by a sol-gel approach. The effect of Co content on the n Co-Al 2O 3 catalyst structure and performance in the oxidativedehydrogenation of ethylbenzene to styrene by CO 2 was investigated. The results showed that the isolated Co 2 +ionson the n Co-Al 2O 3 catalysts had a positive influence on the catalytic activity, where the isolated tetrahedral Co 2 +species were considered as the active sites. Co contents on the Co-Al 2O 3 catalyst greatly affected the structure of Cospecies and the catalytic performance. The isolated tetrahedral Co 2 +species are preferentially generated on the resultant n Co-Al 2O 3 catalyst when the content of Co (n ) is less than 10%; as a result, an increase of Co content hereleads to the formation of more isolated Co 2 +sites and then improves the catalytic activity of n Co-Al 2O 3 in the dehydrogenation of ethylbenzene. When Co content exceeded 10%, crystalline Co 3O 4 particles were obtained on theformed catalyst, which resulted in the decline of the isolated Co 2 +sites and catalytic activity. Among various n Co-Al 2O 3 catalysts, 10Co-Al 2O 3 exhibited the best catalytic performance, with 64.4% conversion rate for ethylbenzene and 99.3% selectivity for styrene at 550 ℃. This catalyst remained stable without obvious deactivation for 30 h ofreaction, which suggests that the isolated Co 2 +species as active sites presented excellent structural stability and excellent anti-coke deposition.Key words: Co-based catalyst ；ethylbenzene ；oxidative dehydrogenation ；CO 2；styrene苯乙烯（ST ）是仅次于聚乙烯、聚氯乙烯和环氧乙烷的第四大乙烯衍生产品，广泛用于生产树脂、塑料和合成橡胶等。
地面用晶体硅光伏组件设计鉴定和定型英文
地面用晶体硅光伏组件设计鉴定和定型英文Design and Identification of Ground-mounted Crystalline Silicon Photovoltaic Modules Abstract:Ground-mounted photovoltaic (PV) systems play a crucial role in the renewable energy industry. The design and identification of the PV modules used in these systems are crucial for their performance and efficiency. This paper presents an overview of the design and identification process, specifically focusing on crystalline silicon PV modules.1. IntroductionGround-mounted PV systems are widely adopted due to their higher power output and easy accessibility for maintenance. The overall efficiency of these systems heavily relies on the quality and design features of PV modules. The design and identification process involves analyzing various factors such as module efficiency, power tolerance, temperature coefficient, and environmental durability.2. Design considerations2.1 Module efficiencyEfficiency is a key performance indicator for PV modules. A higher efficiency module converts more sunlight into electricity, resulting in increased energy production. During the design process, the module efficiency should be considered to maximize the energy output of the system.2.2 Power tolerancePower tolerance refers to the range in which the actual power output of the module can deviate from its rated power output. Designing PV modules with tight power tolerances ensures consistent performance and energy production.2.3 Temperature coefficientThe temperature coefficient of a PV module indicates its sensitivity to changes in temperature. A low temperature coefficient allows the system to perform optimally even in high-temperature environments.2.4 Environmental durabilityGround-mounted PV modules are exposed to various environmental factors such as wind, rain, and snow. The design should ensure that the modules are durable and can withstand these elements, preventing damage and ensuring long-term performance.3. Identification process3.1 Standard compliancePV modules must comply with international standards such as IEC 61215 and IEC 61730 to ensure quality and performance. The modules are subjected to rigorous testing and evaluation before certification is granted.3.2 Electrical performance testingElectrical performance testing includes measuring the open-circuit voltage, short-circuit current, maximum power voltage, and maximum power current. These parameters provide important insights into the module's electrical characteristics.3.3 Thermal imagingThermal imaging is used to identify any hotspots on the PV modules which can indicate potential defects or malfunctioning cells. Hotspots can lead to efficiency losses and should be identified and addressed during the design phase.3.4 Outdoor performance evaluationOutdoor performance evaluation measures the actual energy output of the modules under real-world conditions. This evaluation provides valuable data to validate the module's performance and efficiency.4. ConclusionThe design and identification of ground-mounted crystalline silicon PV modules require careful consideration of various factors such as efficiency, power tolerance, temperature coefficient, and environmental durability. Compliance with international standards, electrical performance testing, thermal imaging, and outdoor performance evaluation are important steps in the identification process. By following these guidelines, designers can ensure the optimal performance and long-term reliability of ground-mounted PV systems.。
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Highly Efficient Saturated PA Design at 3.5 GHz UsingMicrowave OfficeMicrowave Office,,POSTECH, EE, MMIC LABJuly 15, 2011Contents•Introductionp •Saturated Power Amplifier •Simulation ResultEM Simulation Tool Verification–EM Simulation Tool Verification–Saturated PAMeasurement Result •Measurement Result •ConclusionStandard evolution ÆData rate↑Bandwidth and PAPR RF PA should provide high efficiency as well as high linearity across the broad output power & frequency rangeResearch Trends in BTS PA Research Trends in BTS PAn c yF/F :FeedforwardET :Envelope Tracking E f f i c i e Saturated Doherty +DPD(HVHBT)DPD :Digital PredistortionLinear Linear Doherty +DPD(GaN)Saturated Doherty +DPD(GaN)ET +DPD(GaN)ET +DPD (LDMOS)Class-AB+F/F (LDMOS)Linear Doherty +F/F(LDMOS)LinearDoherty +DPD (LDMOS)TimeLinearization Technique :F/F &DPDEfficiency Enhancement Technique :Doherty &ET•F/F and DPD are preferred for linearization technique •Doherty and ET transmitter are selected for efficiency h h ienhancement techniqueDesign Overviews for IMS HighEfficiency PA DesignDesign Target•Design Target –Device : Cree GaN HEMT CGH40006P (6-Watt PEP)–Substrate : Taconic TLY-5 20mil (= 2.2)Subs a e aco c 50(εr )–Aluminum Fixture –Frequency : 3.5 GHzO tp t Po er >37dBm –Output Power : > 37 dBm –Input Power : < 25 dBm–Efficiency : As much as possible y p –Saturated Power AmplifierPower amplifier is optimized based on the•Power amplifier is optimized based on the momentum simulator, AXIEM , in Microwave Officeoperates in a gm-driven saturated mode, not as a switch V & I are in-phase enhancing the performance•The output capacitor presents a severeAs the drain voltage is decreased, the capacitance isAs the decreasedincreased very rapidly: generate a large second harmonicsThe nonlinear capacitor generates the harmonic voltage components The second and third harmonics of the current source do not generated d thi d thenough harmonic out voltagesThe flat bottom and sharp peaking in voltage waveform, indicating the proper second harmonic voltage component for enhanced performance proper second harmonic componentFundamental Load Impedance at the current source Waveforms are similar to the Class-FHalf-sinusoidal voltage waveform, rectangle current waveformTo increase the voltage waveform, the fundamental load impedance should be larger than √2·R optlargeris the optimum load impedance when all harmonics are short2 represents the maximum increment extracted from half-sinusoidalg,Due to the highly saturated operation, the fundamental currentFundamental load impedance of the Class-P PA ≥As a rule of thumb,≤ Fundamental load impedanceHarmonic Impedance toward the external loadVoltage waveform is entirely shaped by the nonlinear capacitor at a Harmonic impedance greater than the level of thenonlinear capacitor is enough to shape the voltageVoltage across the capacitor is mainly provided by fundamental2ndHigh efficiency is maintained across the broad harmonicVoltage WaveformVoltage Waveform•Cree’s GaN HEMT CGH60008 bare-chip deviceFrequency (GHz)I dsq(mA)Pin (dBm)Pout (dBm)Gain (dB)DE (%)PAE (%)3.5502437.3613.3386.3683.82TL O2 2TL L O3Schematic & Layout in MWO Schematic&Layout inSize: 60mm X 100mmSize:60mm X100mmEM Simulation Tool Verification EM Simulation Tool Verification•50 Ohm line•25 Ohm line•Simple matching circuit•Measurement using network analyzer•EM simulation using AXIEM50Ohm line50 Ohm lineMeasurement AXIEMS11,S22(dB)S12,S21(dB)25Ohm line25 Ohm lineMeasurement AXIEMS11,S22(dB)S12,S21(dB)Simple Matching CircuitSimple Matching CircuitMeasurement AXIEMS11,S22(dB)S12,S21(dB)Simple Matching Circuit MeasurementAXIEMSimple Matching CircuitS11(dB)EM StructureEM Structure•Extracted from layout•Using AXIEM•Meshing Frequency: 0~10.5GHz(considering 3rd harmonic), 25 pointsSimulation Results Simulation ResultsBold:EM Simulation(AXIEM)Blurred:Schematic Simulation2011IMS PA Competition 2011 IMS PA CompetitionWith AWR’h t th t PA d i d b MWO t •With AWR’s huge support, the sat. PAs designed by MWO got 1stand 2nd places at 2011 IMS High Efficiency PA Student Design CompetitionConclusion•This presentation shows the design of the winning PA at 2011 IMS Student Design Competition using AWR Microwave Officeg g•The good agreement between simulation and measurement of the PA is demonstrated Saturated PA at 3.475GHz with remarkable •Saturated PA at3.475GHz with remarkable performanceoutput power 38.3 dBm, Gain 14.4 dBm, DE 83.1% –output power38.3dBm,Gain14.4dBm,DE83.1%and PAE 80.1%Thank you!!。