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 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 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.

The synergetic enhancement of hydrogen evolution is achieved over Sn, Ru co-modified TiO2 photocatalysts based on efficient charge separation driven by an inner electric field formed between the Sn–O–Ti and Ru–O–Ti heterojunctions. The physical model is extremely similar to an electrolysis cell, where RuO2 serves as an anode and single-site Sn-oxo species act as a cathode as well as TiO2 being mainly responsible for the conversion of photons into electrical energy.Figure optionsDownload high-quality image (129 K)Download as PowerPoint slide