A novel g-C3N4 based photocathode for photoelectrochemical hydrogen evolution

Nowadays, the fabrication of photocathodes with high light-harvesting capability and charge transfer efficiency is a key challenge for photoelectrochemical (PEC) water splitting. In this paper, a novel graphitic carbon nitride (g-C3N4) based photocathode was designed, prepared and used as a photocathode for hydrogen generation from water. Here we employed g-C3N4 as a photosensitizer and co-catalyst for photoelectrochemical hydrogen evolution for the first time. The g-C3N4 based photocathode exhibited superior light absorbance and excellent photoactivity. Under irradiation, the photocurrent response of the g-C3N4/NiO photocathode at a bias potential of 0 vs. RHE is approximately ten times that of the NiO photoelectrode and twenty times that of the g-C3N4 photoelectrode. And the g-C3N4/NiO photocathode has excellent activity for hydrogen production with nearly 100% Faraday efficiency without external co-catalyst and buffer solution. Moreover, the g-C3N4/NiO photoelectrode showed superior stability both in nitrogen-saturated and air-saturated neutral environments.