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

• Published in: Applied catalysis. B, Environmental Environmental, 2022-10, Vol.315, p.121570, Article 121570
• Main Authors: Ma, Kangwei, Zhang, Meiyu, Sun, Wanjun, Dong, Congzhao, Dong, Yinjuan, Hao, Weichang, Ding, Yong
• Format: Article
• Language: English
• Subjects: Bulk-doped; H2 production; Photocatalysis; Surface-doped; TiO2
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2022.121570

Visible-light catalytic H2 production is being actively studied as a promising route to replace fossil fuel and improve the environment. Anion doped TiO2 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 TiO2 (OB/TiO2) and surface to bulk B-doped TiO2 (STB/TiO2) were prepared successfully. They exhibited excellent visible-light catalytic H2 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 TiO2 (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 (Ti4+O2-Ti4+O•-) was identified in subsurface of TiO2. Surface B would accelerate the recombination of photo-generated carriers, and thus render the photocatalytic performance of OB/TiO2 superior to STB/TiO2. This work provides valuable insights for rationally designing anion doped TiO2 and maximizing the photocatalytic efficiency via structural optimizations. [Display omitted] •Two kinds of TiO2 with different B doping depth showed excellent visible-light catalytic H2 production activity.•A behavior that directional deposition of Pt induced by electron-deficient structure was observed.•Photo-generated hole trapping site (Ti4+O2-Ti4+O•-) was identified in subsurface of TiO2.•Surface doping may also inhibit the photocatalytic activity compared to bulk doping.