Bimetal-modified g-C3N4 photocatalyst for promoting hydrogen production coupled with selective oxidation of biomass derivative

The solar-driven coproduction of hydrogen (H 2 ) fuel and value-added chemicals from biomass derivatives represents a promising strategy to address the energy and environment issues. Herein, the Ni-Au bimetal modified g-C 3 N 4 photocatalyst was synthesized by a step-by-step photodeposition method and used to promote the photocatalytic coproduction of H 2 and furfural from furfural-alcohol aqueous solution. In the designed Ni-Au/g-C 3 N 4 photocatalyst, g-C 3 N 4 was the main light-harvesting material for generating electron-hole pairs which were separated efficiently by metal/g-C 3 N 4 interface, plasmonic Au nanoparticles further increased the light utilization efficiency, and Ni acted as both electron trap and the active sites for H 2 evolution. Beneficial from the synergy of three components, the Ni-Au/g-C 3 N 4 photocatalyst exhibited 3-folds activity of Au/CN sample toward photocatalytic coproduction of H 2 and furfural. Both photoluminescence spectroscopy and photoelectrochemical measurements demonstrated the more efficient separation and transfer of photogenerated charge carriers in Ni-Au/g-C 3 N 4 photocatalyst. In situ electron spin resonance revealed the generations of hydroxyl radical and carbon center radical in the photocatalytic reaction. Based on the systematic characterizations, a photocatalytic mechanism was proposed and discussed. This work provides a rational construction of photocatalysts for coproduction of H 2 and value-added chemicals from biomass derivatives as well as explores the synergistic effect of bimetallic cocatalyst on enhancing the photocatalysis.