钒酸铋可见光催化材料的改性研究进展

Research Progress on Modification of Bismuth Vanadate Visible Light Photocatalytic Materials

环境污染和能源短缺是21世纪人类迫切需要解决的两大难题,太阳能取之不尽、用之不竭,如何利用太阳能治理环境污染以及缓解能源短缺问题成为人们关注的焦点。钒酸铋(BiVO_(4))因其低成本、无毒、光稳定性好、带隙较小、对可见光具有良好的响应等诸多优势,是一种非常有前景的太阳能驱动的半导体光催化剂,成为光催化领域研究的热点。在BiVO_(4)的三种晶体类型中,单斜相BiVO_(4)由于较小的带隙以及特殊的电子结构具有更高的可见光催化活性。但由于纯BiVO_(4)能隙较窄,导致光生载流子极易快速复合,加之材料存在吸附性以及比表面积较小等缺陷,限制了其光催化活性的提高和实际应用。为了提高BiVO_(4)的可见光催化活性,科研工作者主要从两个方面对BiVO_(4)进行改性修饰,一方面从纯BiVO_(4)入手,通过对BiVO_(4)微/纳米结构的可控合成来提高材料的比表面积和吸附性以及对光生载流子的传导能力等;另一方面通过构筑复合材料,以促进光生电子-空穴对的分离,降低其复合概率,进一步拓宽可见光响应范围,提高材料的吸附性和稳定性等,这些研究已经取得了可喜的成果,目前BiVO_(4)材料的光催化效率大幅提升。本文根据提高BiVO_(4)光催化性能的方法不同对BiVO_(4)可见光催化材料的研究进行了综述,主要包括BiVO_(4)微/纳米结构的可控合成、贵金属沉积、元素掺杂、半导体复合以及BiVO_(4)负载五种改性方法,重点介绍了材料在废水中有毒有机污染物降解、光解水制氢、CO_(2)还原以及有机合成等方面的应用。最后针对该领域的研究现状展望了未来的发展方向,并指出了当前研究中亟待解决的问题,以期为开发稳定高效的BiVO_(4)光催化材料提供参考。

Environmental pollution and energy shortage are the two major problems that need to be solved urgently in the 21st century.Solar energy is inexhaustible energy,how to use solar energy to control environmental pollution and alleviate energy shortage has become the focus.Bismuth vanadate(BiVO_(4))is a promising solar-driven semiconductor photocatalyst due to its low cost,non-toxicity,high photostability,narrow band gap,good response to visible light,and has become a hotspot in photocatalyst field.Among the three crystal types of BiVO_(4),the monoclinic phase BiVO_(4) exhibits the best photoactivity due to the smaller band gap and special electronic structure.However,the fast recombination of photoinduced carriers of pure BiVO_(4) as a result of narrow energy gap,coupled with its low adsorption and small specific surface area,limit the improvement of photocatalytic performance and practical application.In order to improve the visible light photocatalytic activity of BiVO_(4),researchers mainly focus on modifying BiVO_(4) from two aspects including the controlled synthesis of BiVO_(4) micro/nanostructure so as to improve the specific surface area and adsorption,as well as the conductivity of photogenerated carriers or constructing composite materials to promote the separation of photogenerated electron-hole pairs,thus reduce their recombination probability,further broaden the visible light response range and improve the adsorption and stability of materials,etc.The research has achieved encouraging results.At present,the photocatalytic efficiency of bismuth vanadate material has been improved greatly.This article provides a review on the recent advances of bismuth vanadate photocatalytic materials based on different modification methods,including the controlled synthesis of BiVO_(4) micro/nanostructure,noble metal deposition,element doping,semiconductor coupling,and BiVO_(4) loading,which mainly focus on the application of the materials in the degradation of toxic organic pollutants in wastewater,hydrogen production from water splitting,CO_(2) reduction and organic synthesis,etc.Finally,some problems that need to be solved and the future development direction are pointed out,so as to provide a reference for the development of stable and efficient BiVO_(4) photocatalytic materials.