Splendid Intrinsic Activity of NiC/Mo₂C@C Nanocubes for Efficient Water Oxidation

Developing inexpensive, efficient electrocatalysts for hydrogen generation gained much attention for water splitting. Herein, the interface engineering concept was proposed to fabricate a corn husk biomass-derived NiC/Mo2C@C-450 heterostructure consisting of NiC and Mo2C embedded in graphitic carbon synthesized by the mechanochemical calcination/magnesiothermic reduction strategy. The NiC/Mo2C heterojunction encapsulated with porous carbon having more interfacial area and high conductivity with exposed catalytic sites leads to moderate hydrogen adsorption energy, improved desorption kinetics, and assisted rapid electron transfer. The optimum catalyst NiC/Mo2C@C-450 affords a low overpotential (GC/NF) of 291:258 mV with a small Tafel slope of 117:103 mV dec–1 and attains stability over 8 h. The activation energy was calculated for electrolysis using NiC/Mo2C@C-450 as 44.00 kJ/mol. The integrated area/number of active sites of NiC/Mo2C@C-450 (4.97 × 10–5 AV/9.98 × 10–3) confirmed MOOH* formation. The superaerophobicity was substantiated by fast gas bubble evolution from the catalyst surface. Using NiC/Mo2C@C-450, we have produced H2 efficiently with a lower power consumption of 761.50 LH2kWh–1. The two-electrode configuration using NiC/Mo2C@C-450/NF//Pt/C/NF required a cell voltage of 1.60 V with great stability in an alkaline solution. The intriguing synthetic strategy will provide a potential avenue for synthesizing other metal carbide catalysts for extensive electrochemical applications.