提高二氧化钛可见光吸收的研究进展

随着社会工业化的发展,环境污染问题日益严重,控制与治理环境污染已经成为人类社会亟待解决的重大科学问题。在众多治理方法中,半导体光催化材料以其独特的性能成为一种理想的环境污染治理清洁材料,主要应用于降解有毒物质、光催化分解水和光电转化等方面。二氧化钛(TiO_2)作为一种应用广泛的宽带隙半导体光催化材料,因其催化活性高、化学稳定性好、对人体无毒害、成本低廉等优点,被认为是最重要的光催化剂之一。然而,TiO_2的禁带宽度较宽(3.2 e V),对光的利用率较低,只能吸收波长较短的紫外光,直接制约着TiO_2的应用。围绕如何拓宽TiO_2的光谱吸收范围,从化学和物理两个方面对近年来实现TiO_2可见光光催化的途径和方法进行了简要总结。化学方面主要对表面光敏化、元素掺杂进行总结,物理方面主要对慢光效应、米氏散射效应及表面等离子体共振进行综述。此外,还在深入理解现有TiO_2可见光体系的光催化机理,发现更高效的体相掺杂剂和表面敏化剂,设计和控制掺杂剂和表面敏化剂存在形态,进一步提高TiO_2光催化效率等方面做了展望。

Progress of TiO2 Photocatalysis Enhanced under Visible Light Irradiation

With the development of industrialized society, environmental pollution has become increasingly serious. Pollution control and management has been the major scientific issue urgently need to be addressed. Among various pollution management methods, semiconductor photocatalytic material, as an ideal cleaning material for pollution control and management due to its unique properties, is mainly used to degrade toxic substances, photocatalytic water splitting and photoelectric conversion, etc. Titanium dioxide (TiO2), as a common wide-band gap semiconductor, is considered as one of the most vital photocatalysts because of its highly photoactivity, chemical stability, non-toxicity, low cost, etc. However, the application of TiO2 is directly restricted by such key scientific and technological problems as low light utilization efficiency and wide band gap (3.2 eV) of TiO2. Approaches and methods of realizing TiO2 visible light catalysis recently were summarized from chemical and physical perspectives. Chemical and physical methods including slow light effects, Mie scattering effect and surface plasma resonance were reviewed. In addition, the work has given prospect regarding deepening photocatalytic mechanism of existing TiO2 visible light system, exploring effective volume phase dopant and surface sensitizer, designing and controlling existing forms of dopant and surface sensitizer, and further improving TiO2 photocatalytic efficiency.