Surface and interface engineering of MoNi alloy nanograins bound to Mo-doped NiO nanosheets on 3D graphene foam for high-efficiency water splitting catalysis

Designing high-efficiency and durable non-noble metal catalysts is essential for the large-scale application of electrocatalytic water splitting. Herein, MoNi alloy nanograins are embedded in Mo-doped NiO nanosheets by partial reduction treatment, which vertically grow on three-dimensional (3D) nitrogen-doped graphene foam substrate ([email protected]@NGF). The hybrid composite demonstrates superb bifunctional electrocatalytic activity towards hydrogen/oxygen evolution reactions. Especially, it possesses the ultra-low hydrogen evolution overpotential of 56 mV at the current density of 10 mA cm−2 in alkaline condition. The excellent catalytic activity and remarkable stability can be attributed to the optimized surface electronic structure of MoNi alloy by Mo doping, the synergy interface interaction between MoNi nanograins and Mo-NiO substrate, and the high conductivity and corrosion resistance of NGF support. Thus, this work provides a new strategy for the high-performance catalyst towards overall water splitting by the dual regulation of surface and interface.