Rational modulation for electron migration in CdS/Au/TiO2 photoanode for efficient photoelectrochemical water oxidation

Abstract Hydrogen production from photoelectrochemical water splitting process to convert solar energy to chemical energy has aroused plenty of attention owing to its carbon-free procedure and economic sustainability. The oxide semiconductors such as nanorods (TNRs) have widely been used as photoanodes materials because of its high stability against photocorrosion, and long minority diffusion length. We design and fabricate a ternary CdS/Au/TNRs photoanode, which exhibits high photocurrent density of 2.78 mA/cm2 at 1.23 V vs RHE and of a further negatively shifted onset potential at −145 mV. The influence of CdS and Au on PEC performance of CdS/Au/TNRs heterojuntion has been systematically studied. We demonstrate that the CdS and Au can effectively enhance the charge separation and improve the conductivity for carrier transport. This work would pave the way towards design heterojunction functional material.