Research Progress of Tungsten Oxide-Based Catalysts in Photocatalytic Reactions

Photocatalysis technology is a potential solution to solve the problem of environmental pollution and energy shortage, but its wide application is limited by the low efficiency of solar energy conversion. As a non-toxic and inexpensive n-type semiconductor, WO₃ can absorb approximately 12% of sunlight which is considered one of the most attractive photocatalytic candidates. However, the narrow light absorption range and the high recombination rate of photogenerated electrons and holes restrict the further development of WO₃-based catalysts. Herein, the studies on preparation and modification methods such as doping element, regulating defects and constructing heterojunctions to enlarge the range of excitation light to the visible region and slow down the recombination of carriers on WO₃-based catalysts so as to improve their photocatalytic performance are reviewed. The mechanism and application of WO₃-based catalysts in the dissociation of water, the degradation of organic pollutants, as well as the hydrogen reduction of N₂ and CO₂ are emphatically investigated and discussed. It is clear that WO₃-based catalysts will play a positive role in the field of future photocatalysis. This paper could also provide guidance for the rational design of other metallic oxide (MO_x) catalysts for the increasing conversion efficiency of solar energy.