Search

• A composite catalyst rGO/NiFe-LDH modified Cu 2 O/TiO 2 heterojunction photocathode has been designed and successfully prepared. • The composite photocathode possesses great photoelectrochemical performance. The photocurrent density is −3.71 mA/cm2 at 0 V vs. RHE and the STE is 0.41%. • The influence of composite catalyst on carrier transport mechanism is discussed by analyzing the variation of the built – in electric field. Cuprous oxide is a highly efficient p-type semiconductor, which has high absorption efficiency in the visible region, making it ideal for the use as a photocathode material for hydrogen evolution reaction. However, the theoretical efficiency of cuprous oxide is still unachievable in practical situations, due to the severe photocorrosion and the high recombination rate of photogenerated electron-hole pairs. In this work, ultra-thin TiO 2 deposited via atomic layer deposition (ALD) was used as a protection layer, and rGO/NiFe-LDH was loaded as a catalyst decoration on Cu 2 O photocathode. The protection layer led to suppression of photocorrosion of Cu 2 O, and the catalyst promoted chemical reaction kinetics. The photo-generated current density reached −3.71 mA/cm2, and the photoelectric conversion efficiency reached 0.41%. The effect of catalyst on the built-in electric field of photocathode and the transport mechanism of carrier were also investigated in detail. This work hereby provides a new idea of the application of Cu 2 O in the domain of photoelectrochemical (PEC) water splitting. [ABSTRACT FROM AUTHOR]