Z-scheme photocatalyst plates using antimony-doped tin oxide (ATO) as a conductive mediator for solar water splitting

Abstract

Printable photocatalyst plates have the potential to use in water splitting system for practicality of solar hydrogen production. In this system, transparent conductive nanoparticles can be inserted as a conductive mediator between hydrogen evolution photocatalyst (HEP) and oxygen evolution photocatalyst (OEP) to promote water splitting reaction. In this paper, we propose a printable SrTiO₃:La,Rh/ATO/BiVO₄:Mo photocatalyst plates incorporating a cost-effective ATO nanoparticles as conductive mediator for Z-scheme water splitting. The photocatalyst plates achieve an apparent quantum efficiency of 6.8% at a wavelength of 420 nm, with a solar-to-hydrogen conversion efficiency (STH) of 0.26%. ATO nanoparticles with excellent visible transparency and electrochemically inert facilitate the charge transfer between HEP and OEP particles. These results show that the nanoparticulate ATO is suitable for promising conductive mediator in the low-cost photocatalyst plates for Z-scheme water splitting.