NiOx nanoparticles as active water splitting catalysts for the improved photostability of a n-GaN photoanode

Abstract In this article, we propose a scheme using the conformal coating of p-NiOx nanoparticles on the n-GaN photoanode to prevent the photoelectrodes from corrosion and thereby enhance conversion efficiency. Furthermore, the various weight ratios of NiOx (1:5 and 3:2) are explored to optimize the study. NiOx nanoparticles avoid corrosion on the n-GaN surface, decrease the solar water-splitting reaction overpotential, and enhance the photocurrent density at a working electrode applied bias of 1 V in the two-electrode system. Finally, in the stability test, the hydrogen evolution rate of NiOx (3:2) is more effective than that of pristine n-GaN even after 5 h. These results indicate that NiOx nanoparticle-decorated n-GaN gains higher photostability and hydrogen production performance in PEC cells.