V ions implanted ZnO nanorod arrays for photoelectrochemical water splitting under visible light

•V ions were successfully injected into ZnO nanorod arrays by advanced ion implantation.•V ion doping expanded the optical absorption of ZnO nanorod arrays into visible light region.•V ions implanted ZnO nanorod arrays showed considerable photoelectrochemical activity in visible light.

In this work, V ions were doped into ZnO nanorod arrays via an advanced ion implantation method for photoelectrochemical water splitting under visible light. It was indicated that the V dopants were incorporated into ZnO lattice as V4+ and V5+ ions. V ion doping expanded the optical absorption of ZnO nanorod arrays into visible light region and led to considerable photoelectrochemical performance under visible light illumination (λ > 420 nm). The photocurrent density of V ions doped ZnO nanorod arrays could achieve 10.5 μA/cm2 at 0.8 V (vs. Ag/AgCl), which was about 4 times higher than that of the pure ZnO nanorod arrays. The enhancement in photoelectrochemical performances for V ions doped ZnO nanorod arrays should be attributed to the improved visible light absorption ability and the increased charge carrier density induced by V ion doping.

Graphical abstractV ions implantation expands the optical absorption of ZnO into visible light, resulting in considerable photoelectrochemical water splitting performances under visible light irradiation.Figure optionsDownload full-size imageDownload as PowerPoint slide