Nb掺杂浓度对SrTiO3的电子结构和光学性能的影响

用第一性原理计算不同Nb掺杂浓度的n型Nb掺杂SrTiO3,研究了Nb掺杂浓度对SrTiO3的形成焓、电子结构和光学性能的影响.在Nb掺杂SrTiO3中Nb替位Ti原子,与实验结果一致.Nb掺杂SrTiO3的费米能级进入导带底部,Nb掺杂SrTiO3呈现n型半导体特征.从微观角度分析了Nb掺杂浓度对导电性的影响,1.11at％ Nb掺杂SrTiO3在可见光范围有强吸收,是一种有潜在应用的光催化材料;而1.67at％和2.5at％Nb掺杂SrTiO3是潜在的透明导电材料.     

SrTiO_3光催化材料的研究进展

简要介绍了近十几年SrTiO3作为光催化材料在制备技术和光催化性能改性方面的进展,并对其未来发展动向进行了简要分析。概述了不同改性方式提高SrTiO3光催化活性的机理,列举了部分SrTiO3光催化材料改性成果和计算学理论工作对提高SrTiO3光催化活性的机理的分析解释,指出随着SrTiO3光催化材料改性体系的完善,不断引进新的实验处理手段结合复合改性方式是SrTiO3光催化材料改性的发展方向,且计算材料学将为其提供有力指导。     

新型光解水制氢用半导体光催化材料的研究进展

综述了钛酸盐、钽酸盐和铌酸盐为主的层状钙钛矿型光催化材料,简述了层状钙钛矿型光催化剂光解水的机理,比较了各种层状钙钛矿型结构材料的催化活性,分析了影响活性的原因,并对层状钙钛矿型结构光催化材料的研究和应用提出了一些自己的观点.     

可见光响应金属氧化物光催化剂的研究进展

研究开发可见光化的光催化剂成为当前光催化剂研究中的重要课题.综述了近年来可见光响应多元金属氧化物光催化剂的研究进展,重点描述了层状、钙钛矿型、尖晶石型、软铋矿型、烧绿石型以及白钨矿型金属氧化物光催化材料的电子结构与可见光光催化活性关系,它们的高可见光催化活性来源于自身的晶体结构和电子结构所引起的禁带窄化和光生电子空穴的有效分离,并对该领域今后的研究工作提出了个人建议.     

铁电材料光催化的研究进展

光催化材料因能利用太阳能净化环境而备受关注。一些铁电材料可以被太阳光激发,实现目标物的降解,且其自发极化有望解决光催化产生电子和空穴的复合问题,成为光催化材料的研究热点之一。对具有铋层状结构、钙钛矿结构、R3c空间群的菱形结构、层状钙钛矿结构和烧绿石结构的铁电材料光催化的研究现状进行了归纳和综述。     

凝胶-燃烧法制备LaNiO3和La2NiFeO6光催化剂的比较研究

采用凝胶-燃烧法制备稀土单钙钛矿型LaNiO_3和双钙钛矿型La_2NiFeO_6光催化剂,利用X射线衍射、BET、红外光谱、扫描电镜进行了表征,并在可见光下以亚甲基蓝为模拟降解物进行了光催化研究。结果表明:钙钛矿LaNiO_3的结构是斜方六面体,而双钙钛矿La_2NiFeO_6的结构是立方体;La_2NiFeO_6的光催化活性高于LaNiO_3,这与二者之间的结构和表面性质的差异有关。     

钙钛矿型氧化物薄膜的制备及光催化降解染料的研究进展

钙钛矿型复合氧化物拥有很高的光催化活性,研究此类氧化物薄膜的制备技术及光催化特性,对促进其在印染废水治理方面的应用,具有重大的实用价值。首先介绍了该类氧化物的光催化机理,简要概括了制备钙钛矿型复合氧化物纳米薄膜常用的几种生长技术,对该类薄膜在光催化降解染料方面进行了综述,最后预测了钙钛矿型复合氧化物薄膜在该领域的研究重点并展望了发展前景。     

钙钛矿氧化物的化学结构及其催化性能的研究进展

钙钛矿氧化物由于其结构的稳定性和特殊的物化性能,日益成为材料科学领域的研究热点.简要介绍钙钛矿的化学结构及其吸附和催化性能,综述了近年来钙钛矿氧化物在催化及光催化领域的研究进展.     

新型氧敏薄膜材料

采用溶胶-凝胶工艺制备了用于汽车新型传感器的氧敏薄膜材料、包括过渡金属氧化物（MoOx、TiOx、CrOx）、钙钛矿型（SrTiO3/LaNiO3、LaNiO3、LaCrO3）和类钙钛矿型（La1-xMxNiO4）纳米粒子薄膜。结果表明,与传统氧传感器用的ZrO2、TiO2半导体材料相比,这三类材料的阻温系数小,敏感度高,响应速度快。     

CsPbBr3钙钛矿的光催化CO2还原研究进展

探索绿色发展、解决能源危机已成为近年来商业发展的趋势。金属卤化物钙钛矿因其独特的光催化性能而备受关注。其中，CsPbBr₃钙钛矿具有较高的光催化活性和优异的稳定性，在光催化CO₂还原方面发展迅速。在能源发展趋势下，减少碳排放和催化还原CO₂作为燃料是研究热点和主要途径。然而，纯CsPbBr₃较差的CO₂吸附还原能力、严重的电荷复合和较低的电荷效率严重阻碍了钙钛矿光催化的商业化。为了解决纯CsPbBr₃材料光催化中的一系列问题，对CsPbBr₃钙钛矿进行表面改性或构建多组分复合材料是目前最经济、最有前景的解决方案。本文讨论了CsPbBr₃钙钛矿的光催化反应原理及所面临稳定性和还原能力的阻碍，对CsPbBr₃钙钛矿及其复合物的光催化CO₂还原研究进行了系统的回顾。最后对构建更加稳定、高效及可持续性的CO₂还原光催化剂新的探索方向进行了展望。     

Recent Progress of Three-dimensionally Ordered Macroporous (3DOM) Materials in Photocatalytic Applications: A Review

In recent years, three-dimensionally ordered macroporous (3DOM) materials have attracted tremendous interest in the field of photocatalysis due to the periodic spatial structure and unique physicochemical properties of 3DOM catalysts. In this review, the fundamentals and principles of 3DOM photocatalysts are briefly introduced, including the overview of 3DOM materials, the photocatalytic principles based on 3DOM materials, and the advantages of 3DOM materials in photocatalysis. The preparation methods of 3DOM materials are also presented. The structure and properties of 3DOM materials and their effects on photocatalytic performance are briefly summarized. More importantly, 3DOM materials, as a supported catalyst, are extensively employed to combine with various common materials, including metal nanoparticles, metal oxides, metal sulfides, and carbon materials, to enhance photocatalytic performance. Finally, the prospects and challenges for the development of 3DOM materials in the field of photocatalysis are presented.     

钙钛矿型氧化合物AgNbO3的水热合成与表征

采用水热法制备了钙钛矿型化合物Ag-NbO3晶体,对化合物进行粉末X射线表征。Rietveld精修结果表明化合物AgNbO3属于三方晶系,空间群为R-3C。并对化合物进行了扫描电子显微镜(SEM)、BET法测定比表面积和对固体紫外漫反射光谱进行表征。对该化合物的光催化性质进行了测试,在可见光照射下降解染料龙胆紫。结果表明此化合物在室温下具有很高的光催化性质,在光催化性能方面具有潜在的应用价值。     

二硫化钼纳米材料在光催化应用中的研究进展

二硫化钼(MoS_2)具有类石墨烯层状结构、良好的光学性能和电子传输特性,在光催化、太阳能电池、光开关等领域具有广阔的应用前景,一直备受关注。综述了近5年MoS_2纳米材料在光催化降解有机物和光催化水解制氢领域内的最新研究进展,分析了MoS_2纳米材料在光催化应用中存在的主要问题与挑战,重点介绍了相关解决方法。最后展望了MoS_2纳米材料在光催化应用中的发展方向和应用前景。     

Nano-photocatalytic materials: possibilities and challenges

Semiconductor photocatalysis has received much attention as a potential solution to the worldwide energy shortage and for counteracting environmental degradation. This article reviews state-of-the-art research activities in the field, focusing on the scientific and technological possibilities offered by photocatalytic materials. We begin with a survey of efforts to explore suitable materials and to optimize their energy band configurations for specific applications. We then examine the design and fabrication of advanced photocatalytic materials in the framework of nanotechnology. Many of the most recent advances in photocatalysis have been realized by selective control of the morphology of nanomaterials or by utilizing the collective properties of nano-assembly systems. Finally, we discuss the current theoretical understanding of key aspects of photocatalytic materials. This review also highlights crucial issues that should be addressed in future research activities.     

Ultrathin 2D Photocatalysts: Electronic‐Structure Tailoring,Hybridization, and Applications

As a sustainable technology, semiconductor photocatalysis has attracted considerable interest in the past several decades owing to the potential to relieve or resolve energy and environmental‐pollution issues. By virtue of their unique structural and electronic properties, emerging ultrathin 2D materials with appropriate band structure show enormous potential to achieve efficient photocatalytic performance. Here, the state‐of‐the‐art progress on ultrathin 2D photocatalysts is reviewed and a critical appraisal of the classification, controllable synthesis, and formation mechanism of ultrathin 2D photocatalysts is presented. Then, different strategies to tailor the electronic structure of ultrathin 2D photocatalysts are summarized, including component tuning, thickness tuning, doping, and defect engineering. Hybridization with the introduction of a foreign component and maintaining the ultrathin 2D structure is presented to further boost the photocatalytic performance, such as quantum dots/2D materials, single atoms/2D materials, molecular/2D materials, and 2D–2D stacking materials. More importantly, the advancement of versatile photocatalytic applications of ultrathin 2D photocatalysts in the fields of water oxidation, hydrogen evolution, CO₂ reduction, nitrogen fixation, organic syntheses, and removal pollutants is discussed. Finally, the future opportunities and challenges regarding ultrathin 2D photocatalysts to bring about new opportunities for future research in the field of photocatalysis are also presented.     

Ag-基等离子体共振光催化剂的研究进展

Ag-基等离子体共振光催化剂因其特殊的物理化学性能,在光催化降解污染物、分解水和生物传感器等方面受到了广泛关注。尤其是Ag/AgX(X=Cl、Br、I)类等离子体光催化剂,由于其在可见光催化降解有机污染物中的优异表现,成为近年来可见光催化领域的研究热点。综述了近年来Ag-基等离子体共振光催化剂的研究进展,并深入探讨了其光催化反应机理。Ag-基等离子体共振光催化剂合成方法简单易行,原料成本低,光催化效率高,必将在应用光催化领域具有良好的发展前景。     

Photocatalytic degradation of C.I. Direct Red 23 in aqueous solutions under UV irradiation using SrTiO3/CeO2 composite as the catalyst

The photocatalytic degradation of C.I. Direct Red 23 (4BS) in aqueous solutions under UV irradiation was investigated with SrTiO3/CeO2 composite as the catalyst. The SrTiO3/CeO2 powders had more photocatalytic activity for decolorization of 4BS than that of pure SrTiO3 powder under UV irradiation. The effects of catalytic dose, pH value, initial concentration of dye, irradiation intensity as well as scavenger KI were ascertained, and the optimum conditions for maximum degradation were determined. Under the irradiation of a 250 W mercury lamp, the best catalytic dose was 1.5 g/L and the best pH was 12.0. Light intensity exhibited a significant positive effect on the efficiency of decolorization, whereas the initial dye concentration showed a significant negative effect. Under the conditions of a catalytic dose of 1.5 g/L, pH of 12.0, initial dye concentration of 100mg/L, light intensity of 250 W, and air flow rate of 0.15 m3/h, complete decolorization, as determined by UV-visible analysis, was achieved in 60 min, corresponding to a reduction in chemical oxygen demand (COD) of 69% after a 240 min reaction. A tentative degradation pathway based on the sensitization mechanism of photocatalysis is proposed.     

负载型SrTiO_3/HZSM-5光催化材料制备与性能研究

采用溶胶-凝胶法制备HZSM-5负载SrTiO_3,对其进行XRD,SEM,BET,BJH和FT-IR表征,研究SrTiO_3/HZSM-5光催化降解活性艳红X-3B的活性。结果表明:SrTiO_3材料的主要成分为钙钛矿结构SrTiO_3,并含有少量SrCO3相。在负载型χSrTiO_3/HZSM-5样品中,SrTiO_3包覆在HZSM-5的外表面。负载型催化剂的比表面积主要由分子筛提供,材料中的孔径主要分布在2~20nm范围内。负载后SrTiO_3的光催化活性明显提高,30%SrTiO_3/HZSM-5具有最强的光催化活性。经90min光照后,93.8%的活性艳红X-3B在30%SrTiO_3/HZSM-5上降解,而在纯SrTiO_3上只能降解23.9%。     

High visible light photocatalytic activities obtained by integrating g-C3N4 with ferroelectric PbTiO3

Graphitic carbon nitride (g-C3 N4) with the merits of high visible light absorption,proper electronic band structure with high conduction band edge and variable modulation,is viewed as a promising photocatalyst for practical use.To alleviate its high recombination rate of photo-excited charge carriers and maximize the photocatalytic performances,it is paramount to design highly effective transfer channels for photo-excited charge carriers.Ferroelectric materials can have the charge carriers transport in opposite directions owing to the internal spontaneous polarization,which may be suitable for constructing the heterostructure with g-C3N4 for efficient charge separation.Inspired by this concept,herein ferroelec tric PbTiO3,which can be the visible-light absorber,is coupled with g-C3N4 to construct PbTiO3/g-C3N4 heterostructure with close contact via Pb-N bond by the facile post thermal treatment.The optimized PbTiO3/g-C3N4 heterostructure exhibited excellent photocatalytic and photoelectrochemical activities under visible light irradiation.Moreover,the simultaneous application of ultrasound-induced mechanical waves can further improve its photocatalytic activities through reinforcing the built-in piezoelectric field.This work proposes a widely applicable strategy for the fabrication of high-performance ferroelectric based photocatalysts and also provides some new ideas for developing the understanding of ferroelectric photocatalysis.