Titanium Oxide Based Photocatalysts: From Research to Applications

Lianzhou      Wang; Gao   Qing   (Max) Lu

Abstract

The increasing concerns for climate change and exhausting supply of traditional energy sources have triggered world-wide research efforts in developing alternative energy generation systems. Photocatalytic process for clean electricity/H2 generation and environmental pollution purification has been considered as one of the most promising solutions to address these key challenges that mankind faces. Among various semiconducting photocatalysts, TiO2 has been recognized as the best candidate to date. In this review, we first introduce the basic mechanisms of photocatalytic reactions addressing the processes of electron-hole generation, recombination, charge transfer and surface redox reactions; followed by the preparation of nanostructured TiO2 and their band-gap/surface modification towards visible light response photocatalytic activity, with a main focus on representative research works and patenting activities. The second part overviews some typical applications of TiO2 which include water splitting for H2 production, air and water pollutant purification, self-cleaning coating and dye-sensitized solar cells. Directing the future scientific and applied research efforts toward rational design of this photocatalyst will play a key role in achieving efficient utilization of solar energy for environmental and energy conversion applications.

Keywords: Titania dioxide, photoctalyst, synthesis, nanostructure, visible light response, band-gap engineering, metal-ion doping, non-metal doping, water splitting, air pollutant purification