Broadband Light Harvesting and Unidirectional Electron Flow for Efficient Electron Accumulation for Hydrogen Generation.

Abstract

The efficiency of solar hydrogen evolution closely depends on the multiple electrons accumulation on the catalytic center for two-electron-involved water reduction. Herein, we report an effective approach to enable broadband light absorption and unidirectional electron flow for efficiently accumulating electrons at active sites for hydrogen evolution by rationally engineering the nanostructure of Pt nanoparticles (NPs), TiO2 , and SiO2 support. In addition to Schottky-junction-driven electron transfer from TiO2 to Pt, Pt NPs also produce hot electrons by recycling the scattered visible and near-infrared (vis-NIR) light of the support. Unidirectional electron flow to active sites is realized by tuning the components spatial distribution. These features collectively accumulate multiple electrons at catalytic Pt sites, thereby affording enhanced activity toward hydrogen evolution under simulated sunlight.