Facile cubic Nd doped MnO nanostructure synthesis as effective electrocatalyst for oxygen evolution reaction

Abstract

Development of an effective electrocatalyst for the electrochemical water splitting to store electrical energy as H2 fuel and improve sluggish oxygen evolution reaction (OER) is the need of the time. For H2 production and making it more accessible, developing a low-cost fabrication method for an efficient OER catalyst with characteristics including a large surface area, an abundance of active sites, and exceptional stability is necessary. In this study, neodymium-doped manganese oxide (Nd-MnO) with a larger specific surface area (32.6 m2/g), small size particles (84 nm), and most crucially high concentration of oxygen vacancies fabricated via a simple solution reduction method using NaBH4 as a reductant. Nd-MnO has an overpotential of 394 mV and a Tafel slope value of 84 mV/dec reaching 10 mA/cm2, superior to RuO2 and MnO. The potential results of the Nd-MnO are due to a unique structure consisting of nanocubes that may enhance OH ion mass diffusion/transport and offer a large number of active sites for catalysis of OER, as well as oxygen vacancies which are also validated by DFT that may enhance the electronic conductivity and provide H2O adsorption on the surface of neighboring Mn3+ sites.