Lycium ruthenicum stem extract mediated green synthesis of MnO₂/Mn₃(PO₄)₂ composite nanowire electrocatalyst for oxygen evolution reaction

Abstract A composite of manganese oxide (MnO 2 ) and Mn 3 (PO 4 ) 2 decorated nanowires (MnO 2 /Mn 3 (PO 4 ) 2 ) was prepared using Lycium ruthenicum stem-extract mediated green synthesis. This composite material functions as an efficient and long-lasting electrocatalyst for water-splitting reactions, which could significantly improve the performance of oxygen evolution reaction (OER). The OER activity of MnO 2 /Mn 3 (PO 4 ) 2 -based nanowires is boosted by blending with a conducting support, such as manganese oxide (MnO 2 ). The x-ray diffraction pattern and Fourier transform infrared data indicate that the nanowires are highly crystalline. The MnO 2 /Mn 3 (PO 4 ) 2 composite material demonstrates superior stability compared to its individual constituents and generates a current density of 10 mA cm −2 at a low overpotential of 244 mV for OER in alkaline media. This research may lead to the development of MnO 2 /Mn 3 (PO 4 ) 2 composite materials as electrocatalysts for overall water-splitting reactions.