Fabrication of Co-Grafted g-C₃N₄/CdSe-NiO Photocathode for Hydrogen Evolution under Visible Light

A photocathode for driving water splitting under visible light was constructed using mesoporous nickel oxide as a substrate, two-dimensional g-C₃N₄ nanosheet/zero-dimensional CdSe quantum dots as a composite photocatalyst, and cobalt oxime catalyst as an economical cocatalyst. The Co-g-C₃N₄/CdSe-NiO cathode displayed a high photocatalytic current density of −56 μA cm^-2 at a bias of −0.1 V vs NHE in the absence of electron sacrifice, which was about 4 times greater than that of the photocathode using only CdSe quantum dots (−15 μA cm^-2) as the photosensitizer. Simultaneously, the Faraday efficiency of the photocathode was about 90.7%.