Ultrathin Ru-CdIn₂S₄ nanosheets for simultaneous photocatalytic green hydrogen production and selective oxidation of furfuryl alcohol to furfural

Biomass is an important sustainable carbon source and converting biomass intermediates into value-added chemicals/fuels using a green technology is a promising sustainable pathway. Dual-functional photocatalysis can be used to “hit two birds with one stone” via the simultaneous production of hydrogen (H₂) and valorisation of the biomass intermediates. CdIn₂S₄ (CIS) is an exciting photocatalytic material because of its high visible-light harvesting capacity. Herein, ultrathin CIS nanosheets were fabricated via a solvothermal method with in situ deposition of Ru (Ru-CIS). The photocatalytic performance of Ru-CIS toward the selective oxidation of furfuryl alcohol (FOH, a biomass intermediate), to a value-added product (Furfural, FCHO) with concurrent generation of hydrogen was investigated. Ru incorporation resulted in up to 50-fold enhancement in H₂ production rate and higher FOH to FCHO conversion% and selectivity%. This enhancement was attributed to the enhanced charge separation due to the incorporated Ru species, as supported by density functional theory (DFT) calculations.