The Combination of Hydrogen and Methanol Production through Artificial Photosynthesis-Are We Ready Yet?

Because 100 % quantum efficiency for the photosynthetic production of H2 from H2 O under visible illumination has been achieved recently, the oxidation of H2 O to O2 remains the bottleneck to the overall water-splitting reaction. Oxidation of CH4 to CH3 OH might be combined with water reduction instead, so that H2 and CH3 OH chemical fuels can be simultaneously produced through a one-step process under solar illumination. This combination would be a promising approach towards a more sustainable future of chemistry, in which developing different strategies for artificial photosynthesis is of paramount importance. By using free and adsorbed HO. radicals on the semiconductor surface, CH4 can be activated to H3 C. radicals and converted into CH3 OH, respectively, with great selectivity up to 100 %. The present lack of efficient photosynthetic systems for the formation of H2 and CH3 OH from abundant H2 O and CH4 motivates future research for basic science and industrial applications.