An orthophosphate semiconductor with photooxidation properties under visible-light irradiation

Abstract

The search for active semiconductor photocatalysts that directly split water under visible-light irradiation remains one of the most challenging tasks for solar-energy utilization1-6. Over the past 30 years, the search for such materials has focused mainly on metal-ion substitution as in In 1-x Nix TaO4 and (V-,Fe-or Mn-)TiO 2(refs 7,8), non-metal-ion substitution as in TiO2-x Nx and Sm2 Ti2O5S2 (refs 9,10) or solid-solution fabrication as in (Ga1-xZn x)(N1-xOx) and ZnS-CuInS2-AgInS 2(refs 11,12). Here we report a new use of Ag3PO 4 semiconductor, which can harness visible light to oxidize water as well as decompose organic contaminants in aqueous solution. This suggests its potential as a photofunctional material for both water splitting and waste-water cleaning. More generally, it suggests the incorporation of p block elements and alkali or alkaline earth ions into a simple oxide of narrow bandgap as a strategy to design new photoelectrodes or photocatalysts.