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.