Sn2+-Doped Double-Shelled TiO2 Hollow Nanospheres with Minimal Pt Content for Significantly Enhanced Solar H-2 Production

摘要

H-2 evolution by photocatalytic water splitting has attracted a lot of attention due to the global depletion of oil resources. Therefore, much effort is devoted to develop low-cost, highly active photocatalysts. Here, a facile strategy is proposed for the synthesis of low Pt content Sn2+-doped double-shelled Pt/TiO2 hollow nanocatalyst (DHS-PtSn2+) with excellent solar H-2 production properties. After calcination in N-2, DHS PtSn2+ showed highest photocatalytic H-2 production rate of 28 502 mu mol h(-1) g(-1), nearly threefold higher than the Sn4+-doped counterpart, thereby demonstrating better synergistic effect of Sn2+ than Sn4+ in H-2 evolution. The influences of calcination atmosphere, Sn2+ content, and Sn/Pt atomic ratio on H-2 production have been investigated with a series of contrast experiments. Besides, the proposed Sn2+-doping strategy could also be applied in other light-sensitive materials (e.g., homemade TiO2 nanoparticles, commercial P25, and g-C3N4), suggesting its extensive applications in H-2 production. Finally, based on the excellent synergistic effect of Sn2+ in H-2 production, a possible photocatalytic mechanism was tentatively proposed.