FeOOH as hole transfer layer to retard the photocorrosion of Cu2O for enhanced photoelctrochemical performance

Photocorrosion of Cu2O photoelectrode regarded as a serious factor extremely restricts its photoactivity. So far, nonetheless, there are few comprehensive reports on the mechanism affecting the stability of Cu2O photocathode in photoelctrochemical (PEC) water splitting. In this work, we firstly explore the influence mechanism for the stability of Cu2O photocathode, revealing that self-oxidation caused by accumulation of photogenerated holes is the main reason to the occurrence of Cu2O photoelectrode photocorrosion. By knowing the dominant deactivation mode of Cu2O photoelectrode, we firstly select FeOOH as a hole transfer layer (HTL) to promote the extraction of photogenerated holes from the bulk of bare Cu2O photoelectrode and thus suppress the self-photooxidation of Cu2O. Furthermore, restraint of photocorrosion combined with increase in its total photoelectrochemistry activity can be accomplished after the surface of FeOOH/Cu2O photoelectrode activated with Pt co-catalyst. This work provides a novel strategy and method for improving the stability of photoelectrodes due to self-redox reactions.