摘要
在各类半导体光催化材料中,反尖晶石结构的锡酸锌(Zn_(2)SnO_(4))因传导率良好、电子迁移率高、物化性质稳定且无毒而成为研究热点。近年来,随着研究的不断深入,人们采用(微波)水热法合成出具有不同形貌结构的Zn_(2)SnO_(4)。但因合成条件对Zn_(2)SnO_(4)形貌的影响很大,且缺乏系统性总结,因而本文概述了(微波)水热合成方法中水热时间、合成温度以及原材料、矿化剂与表面活性剂类型和浓度对Zn_(2)SnO_(4)晶体构型、表面电子结构、形貌特征、粒径尺寸及催化性能的影响,以期指导Zn_(2)SnO_(4)特定形貌的可控合成。此外,本文还介绍了提升Zn_(2)SnO_(4)光催化活性的改性策略,即元素掺杂、构建异质结、单质负载(贵金属沉积)、形貌调控和缺陷工程,系统总结了各种改性策略对能带结构、光吸收、光生载流子分离迁移、表面催化反应和光催化性能的影响。最后,展望了Zn_(2)SnO_(4)基半导体光催化材料在各类光催化应用中所面临的挑战与机遇。
Solar energy utilization is a significant way to solve the environmental and energy problems accompanying with the fossil fuel economy development,while artificial photosynthesis imitated semiconductor photocatalysis is one of important solar energy utilization strategies.As a sustainable tactics can be qualified for solving the issues of energy crisis and environmental pollution,semiconductor photocatalysis holds a comparably significant role among various treatment technologies.The core of semiconductor photocatalysis is inseparable from the development of efficient photocatalysts.In fact,there are a large number of binary metal oxides (TiO_(2),Fe_(2)O_(3),ZnO,CdS,SnO_(2),etc.) and even more stable ternary Ⅱ-Ⅳ-Ⅵ metal oxides (SrTiO_(3),CaTiO_(3),Zn_(2)GeO_(4),ZnIn2S4) can work as photocatalytic materials.Among various semiconductor photocatalytic materials,zinc stannate (Zn_(2)SnO_(4)) with inverse spinel structure has become a research hotspot due to its good conductivity,high electron mobility,stable physicochemical properties and non-toxicity.The development of Zn_(2)SnO_(4)contributes to the environmental alleviation and the energy production to some extent,of which has been considered as a rising star photocatalyst.However,the unmodified Zn_(2)SnO_(4)can only respond to UV-light,in the meantime,the recombination rate of photogenerated electron-hole pairs is quite fast,the surface-active sites are relatively limited,resulting in its poor photocatalytic behavior and stability during the reaction process.Up to now,much effort has been devoted to the enhancement of photocatalytic performance over Zn_(2)SnO_(4),including doping,semiconductor heterojunctions,metallic loading and morphological or defect engineering.Amongst,doping requires the introduction of alien elements into Zn_(2)SnO_(4)via physical or chemical approaches,leading to the formation of new charges within the crystal,producing defects or altering the lattice types,and thus changing the electronic structure and the distribution of photo-generated carriers of Zn_(2)SnO_(4).As for semiconductor heterojunctions,combining with two or more kinds of semiconductor materials in a certain way on the micro/nano scale is needed,which would be a modification of the charge of one semiconductor to the another.By combination of the advantages of two or more materials can effectively regulate the performance of a single semiconductor.Whilst for the metallic loading,a single metallic or bimetallic element loading is indispensable,and thereby expanding the light absorption range and accelerating the diffusion of photo-generated electrons to the particle surface to participate in the subsequent catalytic reaction.By comparison,morphological engineering seems to be achieved in an easy manner.Morphology,in face,directly determines the physical properties of catalytic materials such as grain size,specific surface area and pore structure.As for defect engineering,it can endow the modified Zn_(2)SnO_(4)photocatalysts with the positive effects on the energy band structure,light absorption and utilization,separation and migration of photogenerated carriers,surface catalytic reactions,and photocatalytic performance.However,one problem is that there is a lack of comprehensive overview on the influence of the microstructure,crystal configuration and internal electronic structure arrangement on the catalytic performance.Herein,in this review,the synthesis methods including(microwave) hydrothermal treatment of Zn_(2)SnO_(4)photocatalysts with micro/nano frameworks were firstly summarized.And then,the effects of the synthesis conditions on the crystal configuration,surface electronic structure,morphological characteristics,particle size and catalytic performance of Zn_(2)SnO_(4)were systematically overviewed.In addition,the abovementioned four modification strategies for Zn_(2)SnO_(4)were introduced accordingly,and the effects of different modification methods on the structure and performance of photocatalytic materials were also well expounded.On the grounds of experimental and theoretical results,it was found that the aforesaid modification tactics can effectively improve the visible light utilization and carrier separation efficiency over Zn_(2)SnO_(4)-based materials.At the same time,three important processes containing the light absorption,carrier dynamics and surface catalytic reaction were carefully analyzed.Importantly,the applications in photocatalysis over Zn_(2)SnO_(4)were also briefly introduced,including photocatalytic reduction of CO_(2),photocatalytic H2evolution by splitting H2O,removal of liquid pollutants,dye-sensitized solar cell,degradation of dyes and photocatalytic oxidation of gaseous contaminants.Although good results had been achieved in the modified Zn_(2)SnO_(4)photocatalysts,there were still challenges in revealing the reaction mechanism on the catalyst surface.For example,different metals (ions/atoms/clusters) doping and co-decoration of doping and defect configurations were more complex cases,of which the corresponding mechanism in the catalytic process had not been clarified.In addition,combining theory with experiment was inevitable to have a better understanding of the reaction mechanism.Even more importantly,research interest had been directed to the obtainment of Zn_(2)SnO_(4)with a greatly improved photocatalytic behavior by a facile modification method under the simulated real environmental condition,which could be expected to accomplish the industrial applications.As a result,to cover the aforementioned concerns in a feasible manner,the prospects and opportunities of the modified Zn_(2)SnO_(4)as an efficient photocatalyst in various photocatalytic applications were outlooked.This review provided some new ideas and directions for the controllable synthesis and modification of Zn_(2)SnO_(4)-based catalytic materials with high catalytic performance.
作者
李宇涵
任自藤
段有雨
欧阳平
吕康乐
Li Yuhan;Ren Ziteng;Duan Youyu;Ouyang Ping;Lv Kangle(Engineering Research Center for Waste Oil Recovery Technology and Equipment,Ministry of Education,Chongqing Key Laboratory of Catalysis and New Environmental Materials,College of Environment and Resources,Chongqing Technology and Business University,Chongqing 400067,China;Key Laboratory of Resources Conversion and Pollution Control of the State Ethnic Affairs Commission,College of Resources and Environmental Science,South-Central Minzu University,Wuhan 430074,China;College of Physics,Chongqing University,Chongqing 401331,China)
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2023年第1期73-89,共17页
Chinese Journal of Rare Metals
基金
国家自然科学基金青年基金项目(51808080,21707036)
重庆市教委科学技术研究计划项目(KJQN201800826,KJZDK201800801,KJQN202000818)
重庆市博士后出站留渝和校内高层次人才引进项目(1856039,1956044)资助。
作者简介
李宇涵(1989-),女,重庆合川人,博士,副研究员,研究方向:纳米材料合成与应用,E-mail:lyhctbu@126.com;通信作者:吕康乐,教授,电话:027-67841369,E-mail:lvkangle@mail.scuec.edu.cn。
