Photocatalytic CO2 reduction vs. H2 production: The effects of surface carbon-containing impurities on the performance of TiO2-based photocatalysts

摘要: Abstract Photocatalytic CO 2 reduction is a useful way to convert solar energy into fuels, mimicking artificial photosynthesis. The gas phase photocatalytic of was investigated with series TiO -based photocatalysts, either bare or modified by Cu(II) grafting and/or Pt nanoparticles deposition and the results obtained in this reaction were compared those production hydrogen photosteam reforming methanol-water mixtures employing same photocatalysts series. rates two reactions largely depend on type photocatalyst exhibit an almost parallel behaviour, both being higher containing noble metal nanoparticles. However, yields CH 4 , other products from still remain very low often decline during runs. Furthermore, methane found be produced under irradiation when contacted water vapour no carbon dioxide. This points major role carbon-containing impurities surface, which may act as hole scavengers source. Two step tests, i.e. cleaning presence followed purging second after addition, allow one discern between gaseous originated . In step, copper grafted surface favours evolution respect fully reduced