Constructing large-size and ultrathin NiCoP nanosheets on an Fe2O3 photoanode toward efficient solar water splitting

Abstract

The sluggish surface oxygen evolution reaction (OER) kinetics at the photoanode/electrolyte interface severely restrict the photoelectrochemical (PEC) performances for water splitting. Herein, we demonstrated the construction of large-size and ultrathin NiCoP nanosheets on hierarchical Fe₂O₃ nanorod photoanodes for significantly promoting the PEC water oxidation activity. Specifically, the obtained NiCoP/Fe₂O₃ photoanodes exhibited an excellent photocurrent density of 3.8 mA cm⁻² at 1.23 V versus the reversible hydrogen electrode (RHE). Comprehensive investigations reveal that the tight interfacial interaction could effectively facilitate the rapid transfer of photogenerated holes from Fe₂O₃ to NiCoP, and the abundant surface active sites on large-size and ultrathin NiCoP cocatalysts dramatically enhance the OER kinetics. These findings may offer a new insight into rational regulation of the photoanode/cocatalyst interface for highly efficient PEC water splitting.