Visible light-driven simultaneous H₂ production by water splitting coupled with selective oxidation of HMF to DFF catalyzed by porous carbon nitride

In this study, we have demonstrated photocatalytic H₂ evolution by water splitting coupled with biomass derived 5-(hydroxymethyl) furfural (HMF) oxidation to a more valued platform chemical, 2,5-diformylfuran (DFF), under visible light using porous carbon nitride (SGCN) for the first time. Simultaneously, a H₂ production rate of 12 μmol h^-1 m^-2 was obtained with a DFF yield of 13.8% with >99% selectivity after 6 h under visible light. The selectivity of DFF was maintained >99% even after longer runs (48 h) with an improved DFF yield of 38.4% and H₂ production rate of 36 μmol h^-1 m^-2. In addition, a H₂ production rate of 6.2 μmol h^-1 m^-2 with 0.15 light-to-fuel efficiency (LFE) and DFF (7.2% yield) were obtained under natural sunlight after 6 h. Thus, this study describes an effective way to utilize both photogenerated electrons and holes for simultaneous H₂ production by water splitting and biomass derived HMF oxidation to DFF, respectively, under natural sunlight.