A novel strategy for loading metal cocatalysts onto hollow nano-TiO2 inner surface with highly enhanced H2 production activity

Abstract

The loading strategy of cocatalysts affects its activity exerting and atom utilization. Here, a novel strategy for loading precious metal (Pt) cocatalysts by means of ultrathin N-doped carbon layer is reported. The strategy is based on a pyrolysis process of predesigned N-containing polymers and Pt complexes on hard-template surface, during which Pt can be reduced by carbon from pyrolysis at high temperatures. Finally, the hollow TiO2 composite with stable and dispersed Pt on its inner surface was prepared. It shows an ultrahigh photocatalytic H2 production activity as high as 25.7 mmol h−1 g−1 with methanol as sacrificial regent, and displays an apparent quantum yield as 13.2%. The improved photocatalytic activity and stability can be attributed to the highly dispersed and ultrafine Pt nanoparticles, enhanced interaction between Pt-species and carbon support, fast photo-excited electron transport from the high graphitization degree of NC layers, ample oxygen vacancies/defects, as well as the manipulated local charge distribution of Pt/NC-layer configuration. Additionally, the universality of the proposed strategy was demonstrated by replacing metal sources (such as, Ru and Pd). This work presented a promising strategy for the design and development of novel photocatalysts, which shows a broad application prospect.