In-situ formation of unsaturated defect sites on converted CoNi alloy/Co-Ni LDH to activate MoS2 nanosheets for pH-universal hydrogen evolution reaction

Developing non-Pt based electrocatalysts that are highly active and stable has attracted much attention to realize the blueprint of the “hydrogen economy”. Herein, an efficient 3d hybrids electrocatalyst, consisting of in-situ reduced CoNi (CN) alloys and CoNi layered double hydroxides (CNL) activated 1T/2H molybdenum disulfide (MoS2), on carbon paper (CP) was proposed. Benefited from the interface effect for water activation and phase engineering for fast electron transfer, the CN/CNL/MoS2/CP exhibits excellent electrocatalytic activity for hydrogen evolution reaction (HER) with low overpotentials in a wide pH range (overpotential at −10 mA/cm2 (η10)= 112 mV in 0.5 M H2SO4, 106 mV in 1 M KOH and 145 mV in 1 M PBS, respectively). Moreover, the mechanisms of HER in alkaline and neutral media have been discussed in detail. It was discovered that the edge-sides of CN/CNL can promote the water dissociation to generate H protons to facilitate the subsequent steps on CN and MoS2 for the release of H2.