ZnO@S-doped ZnO core/shell nanocomposites for highly efficient solar water splitting

Abstract Prohibiting the rapid holes recombination is a key issue for designing highly efficient photoelectrodes for solar water splitting. Here, we propose a strategy incorporating S atoms in the surface shell of ZnO nanoparticles to generate holes trapper for restraining the electron–hole recombination. The obtained ZnO@S-doped ZnO core/shell-like nanocomposite exhibits a high photocurrent density of 1.08 mA cm −2 with conversion efficiency up to 0.74%, 8 times larger than that of pristine ZnO nanoparticles. Comprehensively, the results from experimental and computational aspects reveal that the S dopants substituting the surface O sites narrow the band gap and introduce a mid-gap impurity band, contributing to the enhanced water splitting activity. This design provides some guides for future optimization of ZnO-based photoelectrodes.