Metal chalcogenide based photocatalysts decorated with heteroatom doped reduced graphene oxide for photocatalytic and photoelectrochemical hydrogen production

Abstract

Heteroatom (N, B and P) doped reduced graphene oxide (RGO)-metal chalcogenide nanocomposites (RGO-Cd0.60Zn0.40S) were prepared by the solvothermal method, and then they were characterized with X-ray diffraction, Raman spectroscopy, transmission electron microscopy, high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, UV–Vis diffuse reflectance spectroscopy and photoluminescence techniques. Doping of RGO with heteroatoms of N, B and P increased charge-transfer capability of nanocomposites and thus, improved both photocatalytic and photoelectrochemical hydrogen production activities of them. N-doped RGO-Cd0.60Zn0.40S photocatalyst exhibited the highest photocatalytic hydrogen production rate (1114 μmolh−1 g−1) in photocatalytic (PC) system amongst other and it was 1.5 times higher than that of RGO-Cd0.60Zn0.40S photocatalyst. Having a current density of 0.92 mAcm−2, photoelectrochemical hydrogen production activity of N-RGO-Cd0.60Zn0.40S electrode was found to be 3 times higher than RGO-Cd0.60Zn0.40S photoelectrode without any applied bias potential under visible light irradiation in photoelectrochemical system. In general, these results clearly showed that heteroatom doping of RGO led to promising materials for renewable hydrogen production in the photocatalytic and photoelectrochemical systems.