Nitrogen-doped Sr2Fe1.5Mo0.5O6-δ perovskite as an efficient and stable catalyst for hydrogen evolution reaction

It is of considerable significance to rationally design electrocatalysts with high efficiency for electrochemical water splitting. Perovskite oxides have received great attention as a prospective type of noble-metal-free candidates for hydrogen evolution reaction (HER) at the cathode, because of the intrinsic activity, distinctive physicochemical properties, and abundant compositions. In addition to the conventional metal element doping approach, non-metal element doping is a significant avenue to strikingly enhance the electrochemical performance of perovskite oxides. Herein, nitrogen-doped Sr2Fe1.5Mo0.5O6-delta (SFMON), synthesized by ammonolysis of Sr2Fe1.5Mo0.5O6-delta (SFMO), is exploited as an outstanding electrocatalyst toward catalyzing HER in alkaline media. With the partial substitution of O by N, the increased contents of oxygen vacancy and high-valence Fe in the SFMON are considered to be favorable for enhancing the HER performance. As such, the overpotential of the optimized SFMON-450 is approximately 149 mV less than that of the parent SFMO at a current density of 10 mA cm(-2), along with higher mass/specific activity, faster HER kinetics, and increased electrochemical active area. More importantly, the constant hydrogen production prolongs to 40 h at a current density of 50 mA cm(-2), much superior to the benchmark Pt/C catalyst, making the SFMON a potential cathode material for water electrolysis devices. (C) 2021 Elsevier Ltd. All rights reserved.