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

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 TiO2 with single-site Sn-oxo species and RuO2 nanoparticles. Detailed characterization and analysis clearly reveal that such TiO2-based composites can function as photoelectrolysis cells, where RuO2 and SnOx species serve, respectively, as an anode and a cathode and TiO2 is mainly responsible for the conversion of photons into electrical energy and the radical dotOH 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 CxHyOz renewables undergo one or more processes for the sequential oxidation of alcohol to aldehyde, acid, and finally CO2 and CO. The activity results indicate that proton reduction is the controlling-rate step of the overall photoreforming reaction.