Hierarchical ZnO nanorod/ZnFe2O4 nanosheet core/shell nanoarray decorated with PbS quantum dots for efficient photoelectrochemical water splitting

Abstract The construction of a uniform heterojunction photoelectrode with rational band alignment and component control has been proved to improve the performance of photoelectrochemical water splitting. Here we prepared ZnO nanorod/ZnFe2O4 nanosheet core/shell nanoarray photoanodes, and PbS quantum dots were further decorated to promote charge transport and act as light absorber. The optimized ZnO/ZnFe2O4/PbS photoanode displays a significantly enhanced photocurrent density and excellent photoelectrochemical stability, and its photoconvertion efficiency is 1.34 and 3.54 times higher than that of ZnO/ZnFe2O4 and ZnO nanorod array photoanodes, respectively, and 87.4% of the initial photocurrent density is obtained after 2 h light irradiation. This work provides a facile strategy for the design of highly efficient and stable photoelectrodes in photoelectrochemical water splitting.