Enhanced CO evolution for photocatalytic conversion of CO 2 by H 2 O over Ca modified Ga 2 O 3 .

Artificial photosynthesis is a desirable critical technology for the conversion of CO 2 and H 2 O, which are abundant raw materials, into fuels and chemical feedstocks. Similar to plant photosynthesis, artificial photosynthesis can produce CO, CH 3 OH, CH 4 , and preferably higher hydrocarbons from CO 2 using H 2 O as an electron donor and solar light. At present, only insufficient amounts of CO 2 -reduction products such as CO, CH 3 OH, and CH 4 have been obtained using such a photocatalytic and photoelectrochemical conversion process. Here, we demonstrate that photocatalytic CO 2 conversion with a Ag@Cr-decorated mixture of CaGa 4 O 7 -loaded Ga 2 O 3 and the CaO photocatalyst leads to a satisfactory CO formation rate (>835 µmol h -1 ) and excellent selectivity toward CO evolution (95%), with O 2 as the stoichiometric oxidation product of H 2 O. Our photocatalytic system can convert CO 2 gas into CO at >1% CO 2 conversion (>11531 ppm CO) at ambient temperatures and pressures.