Revealing different depth boron substitution on interfacial charge transfer in TiO2 for enhanced visible-light H2 production

Visible-light catalytic H 2 production is being actively studied as a promising route to replace fossil fuel and improve the environment. Anion doped TiO 2 is a kind of modified semiconductor with great research potential. However, the depth of anion substitution is difficult to control and hence its impact on photo-generated carriers is controversial. In addition, the effect of interfacial anion doping on the deposition behavior of co-catalyst is not clear. Herein, only bulk B-doped TiO 2 (OB/TiO 2 ) and surface to bulk B-doped TiO 2 (STB/TiO 2 ) were prepared successfully. They exhibited excellent visible-light catalytic H 2 production rate, which were 73 times (488.4 μmol/g/h) and 26 times (171.6 μmol/g/h) higher than that of the Blank TiO 2 (6.7 μmol/g/h), respectively. By multiple characterizations, directional deposition of Pt induced by electron-deficient structure was observed and photo-generated hole trapping site (Ti 4+ O 2- Ti 4+ O •- ) was identified in subsurface of TiO 2 . Surface B would accelerate the recombination of photo-generated carriers, and thus render the photocatalytic performance of OB/TiO 2 superior to STB/TiO 2 . This work provides valuable insights for rationally designing anion doped TiO 2 and maximizing the photocatalytic efficiency via structural optimizations. Revealing different depth boron substitution on interfacial charge transfer in TiO 2 for enhanced visible-light H 2 production. We designed two kinds of TiO 2 with different B doping depth, and they showed excellent visible-light catalytic H 2 production activity. Through comparison, we revealed the influence of B-doped site on photo-generated charge transfer. • Two kinds of TiO 2 with different B doping depth showed excellent visible-light catalytic H 2 production activity. • A behavior that directional deposition of Pt induced by electron-deficient structure was observed. • Photo-generated hole trapping site (Ti 4+ O 2- Ti 4+ O •- ) was identified in subsurface of TiO 2 . • Surface doping may also inhibit the photocatalytic activity compared to bulk doping.