A particulate (ZnSe) 0.85 (CuIn 0.7 Ga 0.3 Se 2 ) 0.15 (ZnSe:CIGS)-based photocathode modified with RuO 2 and Pt species exhibited improved photoelectrochemical activities and stability for hydrogen evolution as well as production of methylcyclohexane, the promising hydrogen carrier, from toluene using a highly alkaline aqueous solution as a hydrogen source under sunlight with almost 100% of faradaic efficiency. It was revealed that the co-loading of RuO 2 with Pt changed the Pt oxidation state, partly explaining the improved activity and stability, associated with an anchoring effect of Pt. It was also determined that such highly alkaline conditions promote selective MCH production, possibly because of the improved performance of the anion exchange membrane. The present study involving the construction of a surface protective/catalytic layer suggests a novel approach to artificial photosynthesis for solar energy harvesting in the form of organic hydrides.