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Developing active, durable, and inexpensive electrocatalysts for the oxygen evolution reaction (OER) is drawing increased interest. Here, a mild hydrothermal–electrodeposition two-step route is designed for the preparation of Ce-doped Ni–S@NiMoO4 micropillar composites on nickel foam (CeNiS@NiMoO4/NF). The as-constructed CeNiS@NiMoO4/NF electrode shows an ultralow overpotential, fast kinetics, superb intrinsic activity and excellent long-term stability for the OER. In 1 M KOH solution, 187 mV overpotential is required to deliver a current density of 10 mA cm−2 with a Tafel slope of 35.28 mV dec−1, and in a saline-alkaline solution of 1 M KOH and 0.5 M NaCl, only 260 mV overpotential is needed to reach 100 mA cm−2, demonstrating its excellent OER performance. The above outstanding electrocatalytic activity is attributed to the influence of CeNiS nanosheets on the surface microstructure of NiMoO4 micropillars, which not only improves the conductivity of the catalyst, but also increases the surface area, as well as accelerates the escape of gases produced. Compared with other non-precious metal OER electrocatalysts, the as-prepared CeNiS@NiMoO4/NF presents stronger or close electrocatalytic activity and better durability, which provides a new electrocatalyst selection in practical applications. [ABSTRACT FROM AUTHOR]

FeNi-layered double hydroxide (LDH) is thought to be an excellent electrocatalyst for oxygen evolution reaction (OER) but it always shows extremely poor electrocatalytic activity toward hydrogen evolution reaction (HER) in alkaline media. Hence, it is significant to improve its HER activity to make it a bifunctional electrocatalyst for the decomposition of water. Here, a simple galvanostatic electrodeposition method was designed for the successful construction of the bifunctional FeNi3@FeNi LDH electrocatalyst. The as-prepared catalyst displayed excellent electrocatalytic activity for HER/OER in 1.0 M KOH. To drive the current density of 10 mA cm−2 for HER/OER, an overpotential of 106/199 mV was needed, respectively. In a two-electrode system with the FeNi3@FeNi LDH/NF as the anode and the cathode simultaneously, the overpotential hardly changed after continuously working for 168 h at 10 mA cm−2. Compared with other FeNi-based catalysts, the present catalyst possessed close or better electrocatalytic activity. [ABSTRACT FROM AUTHOR]