Single-nanoparticle measurements of charge transport in SrTiO3:Rh and BiVO4 photocatalysts for Z-scheme water splitting

Abstract

Solar-powered water splitting using nanoparticle photocatalyst suspensions is a promising route to a clean hydrogen economy. A key step in the water-splitting process is the transport of photo-excited electrons and holes to the photocatalyst surface, where they undergo redox reactions. Here we characterize charge transport in individual SrTiO3:Rh and BiVO4 nanoparticles using a nanoprobe within a scanning electron microscope, and directly map photocarrier diffusion lengths with electron-beam induced current. We find that performance in this system is limited by poor e-h transport within the hydrogen-evolving SrTiO3:Rh nanoparticles.