Mesoporous black TiO2 phase junction@Ni nanosheets: A highly integrated photocatalyst system

Abstract

Solar fuels production by using TiO2 nanomaterials has attracted much attention to overcome the energy and environmental crisis. However, it is a big challenge to utilize the visible light, promote charge separation and surface reaction, and efficiently recover nanosized TiO2 photocatalysts without secondary contamination. Here, Ni nanosheets as the non-noble metal co-catalysts are coated on the surface of mesoporous black TiO2 phase junction microspheres (Ni/b–TiO2) for highly efficient H2 evolution. The black TiO2 phase junction core can efficiently harvest the visible light and greatly facilitate the charge transfer. The Ni nanosheet shell can not only serve as a highly efficient collaborative co-catalyst to promote the separation and transfer of photogenerated charge carriers, but also enhance the visible light absorption and improve the utilization ratio of sunlight. The obtained Ni/b–TiO2 exhibits a high hydrogen evolution rate of 166.2 µmol h-1 g-1 under simulated sunlight, which is much higher than that of pristine mesoporous black TiO2 microspheres (80.5 μmol h-1 g-1). More importantly, the obtained photocatalysts can be easily separated through magnetic separation. Such a structure design may provide new insights for fabricating low-cost bifunctional photocatalysts with high-performance.