Titania-based photocatalysts—crystal growth, doping and heterostructuring

Semiconductor photocatalysts have important applications in renewable energy and environment fields. To overcome the serious drawbacks of low efficiency and narrow light-response range in most stable semiconductor photocatalysts, many strategies have been developed in the past decades. This review attempts to provide a comprehensive update and examination of some fundamental issues in titania (TiO2)-based semiconductor photocatalysts, such as crystal growth, doping and heterostructuring. We focus especially on recent progress in exploring new strategies to design TiO2-based photocatalysts with unique structures and properties, elucidating the chemical states and distribution of dopants in doped TiO2, designing and fabricating integrated heterostructure photocatalysts with different charge-carrier transfer pathways, and finally identifying the key factors in determining the photocatalytic efficiency of titania-based photocatalysts.