Photocatalytic selective oxidation of biomass-derived 5-hydroxymethylfurfural to 2,5-diformylfuran on WO3/g-C3N4 composite under irradiation of visible light

•5-HMF can be converted to DFF by a green photocatalytic selective oxidation process.•10.5% WO3/g-C3N4 composite catalyst exhibits good performance under visible light.•A high DFF selectivity of 87.2% can be achieved under visible light.•The catalytic process follows a Z-scheme mechanism.