Designing a high efficient, cheap and green water oxidation catalyst (WOC) is one of the most important challenges in the sustainable energy field. The CaMn₄O₅ cluster in nature’s photosystem II catalyzes photosynthetic splitting of water into oxygen and protons.¹ Therefore, many researchers focus on modelling this metalloenzyme center by metal complexes with different ligands, as well as through various metal oxides.² According to undeniable role of manganese in the natural water oxidation reaction, manganese oxides are promising as environmentally friendly catalysts.² Their optimization is a sustainable way to robust materials for applications. In this work, molybdenum doped manganese oxide was synthesized and characterized by PXRD, XPS, TGA, FT-IR, Raman, BET, SEM, and HRTEM. In addition, the catalytic activity of doped molybdenum manganese oxide in chemical, photochemical and electrochemical water oxidation reactions are investigated. Results show that molybdenum has a significant effect on the chemical activity of manganese oxide in ceria solution. The water oxidation experiment under the photochemical conditions with Mo doped Mn₂O₃/[Ru(bpy)₃]²⁺/S₂O₈²⁻ also led to promising results (TOF ∼0.83 μmol O₂.m^-2.s^-1).

[1] Yasufumi Umena, Kawakami Keisuke, et al. Nature, 2011, 473, 55-60.
[2] Mohammad Mahdi Najafpour, Renger Gernot, et al. Chem. Rev., 2016 116, 2886-2936.