Color TiO2 Materials as Emerging Catalysts for Visible-NIR Light Photocatalysis, A Review

Titanium dioxide (TiO2), which is a white material, is one of the most practical and prevalent photocatalysts, since it is abundant, chemically stable, nontoxic, and cost-effective. However, white TiO2 absorbs only UV light due to its large band gap, which extremely limits its further development. This has stimulated intensive efforts to tune the band gap of TiO2 for visible-NIR sensitive photocatalysis, creating an emerging material – color TiO2 as one of the most important milestones for photocatalysts. In this review, the recent progress in color TiO2 photocatalysts are discussed with emphasis on strategies of material design and synthesis for visible-NIR light response, including (1) metal-doping, (2) nonmetal-doping, and (3) hydrogen reduction. Applications of color TiO2 are reviewed for photocatalytic degradation of environmental pollutants, production of hydrogen, and photocatalytic CO2 reduction. This review will aid understanding of the advances and challenges in the development of promising visible-NIR light responsive photocatalysts.