In nature, plants convert solar energy into chemical energy via water oxidation. Inspired by natural photosynthesis, artificial photosynthesis has been gaining increasing interest in the field of sustainability/green science and technology as a non-natural and thermodynamically endergonic (ΔG° >
0, uphill) solar-energy-driven reaction that uses water as an electron donor and a source material. Among the artificial-photosynthesis processes, inorganic-synthesis reactions via water oxidation, including water splitting and CO