Single-site Sn-grafted Ru/TiO2 photocatalysts for biomass reforming: Synergistic effect of dual co-catalysts and molecular mechanism

Abstract This work offers an engineering guide to obtaining highly efficient photocatalysts for hydrogen production. Synergetic enhancement of photocatalytic hydrogen evolution from biomass/water solution is achieved by co-modifying anatase TiO 2 with single-site Sn-oxo species and RuO 2 nanoparticles. Detailed characterization and analysis clearly reveal that such TiO 2 -based composites can function as photoelectrolysis cells, where RuO 2 and SnO x species serve, respectively, as an anode and a cathode and TiO 2 is mainly responsible for the conversion of photons into electrical energy and the OH formation. Electron paramagnetic resonance and infrared spectroscopy studies suggest a free radical reaction pathway triggered by the hole oxidation for the photocatalytic reforming of biomass. The C x H y O z renewables undergo one or more processes for the sequential oxidation of alcohol to aldehyde, acid, and finally CO 2 and CO. The activity results indicate that proton reduction is the controlling-rate step of the overall photoreforming reaction.