Carbon-Bridged g-C3N4 Nanosheets for High Hydrogen Evolution Rate by a Two-Step Gaseous Treatment

Carbon nitride (g-C3N4) possesses a bright prospect in transforming solar power into chemical energy by photocatalytic hydrogen production. However, low specific surface area and rapid charges recombination of bulk g-C3N4 obtained by direct thermal polymerization restrict its photocatalytic water splitting efficiency. Herein, carbon-bridged g-C3N4 hybrid nanosheets were synthesized by a two-step gaseous treatment composed of gaseous stripping in wet N-2 ambience and carbon deposition in ethanol ambience. The obtained hybrids possess high optical absorption and low recombination rate at the same time. Furthermore, the deposited carbon acts as the bridge between g-C3N4 and co-catalyst Pt, which facilitates the electron transfer. With 3 wt% Pt as co-catalyst, the optimized C/g-C3N4 (5) hybrid nanosheets achieve the highest hydrogen evolution rate of 8536 mu mol.h(-1).g(-1), which is 11 times that of bulk g-C3N4.