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

Because 100 % quantum efficiency for the photosynthetic production of H 2 from H 2 O under visible illumination has been achieved recently, the oxidation of H 2 O to O 2 remains the bottleneck to the overall water‐splitting reaction. Oxidation of CH 4 to CH 3 OH might be combined with water reduction instead, so that H 2 and CH 3 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, CH 4 can be activated to H 3 C . radicals and converted into CH 3 OH, respectively, with great selectivity up to 100 %. The present lack of efficient photosynthetic systems for the formation of H 2 and CH 3 OH from abundant H 2 O and CH 4 motivates future research for basic science and industrial applications.