NiMo/Cu-nanosheets/Ni-foam composite as a high performance electrocatalyst for hydrogen evolution over a wide pH range

We designed and fabricated non-precious and highly efficient electrocatalysts of nickelmolybdenum/copper-nanosheets/nickel-foam composites (NiMo/Cu-NS/NF) by step electrodepositions, combining with chemical oxidation method. The catalysts were charaterized by means of SEM, XRD and XPS spectra. Their electrocatalytic activities were assessed by hydrogen evolution reactions (HER) over a wide pH range, where acidic, neutral and alkaline electrolytes were used, respectively. Benefiting from the unique midlayer Cu nanosheets (NS) architecture and optimum Mo–Ni composition at the surface layer which led to high electronic conductivity and large electrochemically active surface area (ECSA), the NiMo/Cu-NS/NF-2 catalyst displayed superior electrocatalytic activities with low overpotentials of η 10 = 43, 86 and 89 mV in 0.5 M H 2 SO 4 , 1.0 M PBS and 1.0 M KOH electrolyte, respectively. Especially in the acidic condition, it exhibited the best electrocatalytic activity with smaller Tafel slope of 54 mV dec −1 and higher exchange current density of 1.93 mA cm −2 . • NiMo/Cu-nanosheets/Ni-Foam catalysts were designed and synthesized successfully. • Cu nanosheets secondary substrate led to higher active area and electron transfer. • NiMo/Cu-NS/NF-2 shows superior pH universal electrocatalytic H 2 evolution activity. • NiMo/Cu-NS/NF-2 has the lowest overpotential and Tafel slope in acidic electrolyte.