Recent Advances in the Use of Black TiO ₂ for Production of Hydrogen and Other Solar Fuels

Black TiO 2 has emerged as one of the most promising photocatalysts recently discovered. The reason behind its catalytic activity is considered to be due to the presence of defects and Ti 3+ species at the surface of black TiO 2 nanostructures, which are crucial for its diverse applications. Moreover, disordered/crystalline surface layers and bulk regions have been identified and appear to influence the intrinsic properties of the material. Here, we present the latest studies on the use of black TiO 2 for metal free hydrogen production, as well as for CO 2 photoreduction and N 2 photofixation. After highlighting the structure/property relations, we conclude with some critical questions and suggest further topics of research in order to better understand the underlying mechanisms of light absorption in black TiO 2 , especially towards solar fuels production.