Photodeposited metal clusters for photocatalytic conversion of CO2 to methanol

Public concern has been heightened by the climatic consequences of the greenhouse effect caused by combustion of fossil fuel. Photocatalysis is a suitable approach for the abatement of contaminants. Two aspects have dominated the research of photocatalysts, namely improvement of visible light absorption and minimization of charge recombination. The later can be improved by a decrease in the particle size and by the addition of small metal clusters that work as electrons sinks. The electron transfer phenomenon is vital to the catalytic cycle and a key aspect in processes such artificial photosynthesis. EPR experiments under UV irradiation were carried out on nano-sized metal supported on TiO2 revealed that the presence of a metal leads to the loss of signal related to the stabilized electrons on the pure TiO2 (Ti3+) when a hole scavenger is present. We are testing the catalysts in methanol production in a photoelectric-reactor, which removes the photogenerated holes electronically.