Preparation and electrocatalytic performance of novel‐integrated Ni‐Mo sulfide electrode materials for water splitting

Abstract Advanced electrode materials for electrocatalysis of electrolytic decomposition are crucial materials in the field of hydrogen production from renewable energy. In this work, a new type of integrated hydrogen evolution electrode material was synthesized by selective acidification etching and in situ growth technology. A novel‐integrated Ni‐Mo sulfide electrode material with a three‐dimensional network structure was successfully prepared using a two‐step method (convenient surface modification and in situ growth techniques), which involved surface modification at 30% HNO 3 for 10 min and followed by annealing treatment at 600 °C for 1 h with 10 °C·min −1 heating rate. The structure displayed an electrochemical active surface area (ECSA) of 30.125 mF·cm −2 , calculated on 0.10–0.30 V (vs. RHE) CV curves with a 5–50 mV·s −1 sweep rate range. The ECSA of other samples was also tested by aforementioned methods, which had great distinction on ECSA with different samples. The novel‐integrated Ni‐Mo sulfide electrode material appeared to have extremity electrochemical performance in a three‐electrode configuration employing 1 M KOH solution as an electrolyte, including an excellent hydrogen evolution overpotential of 346 mV at the current density of 500 mA·cm −2 , superior Tafel slope with 103 mV·dec −1 . Such outstanding electrochemical performances of the novel‐integrated Ni‐Mo sulfide electrode materials were directly related to the distinctive integrated structure. Therefore, it was facility to find that the successful preparation of novel‐integrated Ni‐Mo sulfide electrode material provided more selection opportunities for alkaline electrolysis of water and offered an innovative mentality for the preparation of other types of electrode materials.