One-Step Hydrothermal Method Realizing Oxygen Vacancy Construction and P Doping of MnO2 to Optimize Its Oxygen Evolution Performance

MnO2 is considered one of the most potential catalysts for the oxygen evolution reaction, but its activity, which is determined by its electronic structure, crystal phase, and morphology, needs to be improved further. However, it is difficult to realize these multiscale structural regulations of MnO2 simultaneously during the preparation. In this study, α-MnO2 nanomaterial with a lot of oxygen vacancies (OVs) and Mn3+ is prepared by a one-step hydrothermal method, during which the protons of HCl can take the oxygen atom away from MnO2 to form a lot of OVs. The introduction of NH4H2PO4 can realize P doping in MnO2 to stabilize the product in the α-phase. In addition, the OV and P can increase the content of Mn3+ and regulate the Mn-O bond length synergistically to optimize the reaction kinetics. As a result, the product shows obviously enhanced catalytic activity. This study provides a one-step method for multiscale structural regulation of MnO2, which can easily create oxygen vacancies and achieve nonmetallic doping to optimize the oxygen evolution reaction (OER) performance of MnO2.