Persian buttercup-like BiOBrxCl1-x solid solution for photocatalytic overall CO2 reduction to CO and O2

The photocatalytic overall conversion of CO2 with H2O to chemical fuel and oxygen mimicking natural photosynthesis is a huge challenge in photocatalysis. This work shows the achievement of the solar-driven photocatalytic overall CO2 reduction with H2O to CO and O2 over a Persian buttercup-like BiOBrxCl1-x solid solution. A CO generation rate of 15.86 μmol g−1 h−1 with the approximate stoichiometric O2 evolution is yielded on BiOBr0.6Cl0.4 solid solution under simulated solar light irradiation, which was about 7.5 and 10.2 times higher than that of pure BiOCl (2.11 μmol g−1 h−1) and BiOBr (1.55 μmol g−1 h−1), respectively. The enhanced photoactivity is contributed to the mediate band gap and energy level tuned by the formation of BiOBrxCl1-x solid solution to facilitate the separation of photogenerated charges. Besides the unique electron structure, the photoinduced oxygen vacancy (OV) formed on BiOBrxCl1-x solid solution also plays an important role in the CO2 reduction.