Electrospun CSNi₃C/Fe₃C@C/NFs-600 Embedded in Porous Carbon shell as an Efficient Electrocatalyst for Water Splitting at Industrial Driven Current Density

Pure-phase carbides suffer from mismatch in H 2 adsorption–desorption kinetics. Herein, we report on heterostructured CSNi 3 C/Fe 3 C@C/NFs-600 consisting of Co 3 C and Ni 3 C nanofibers embedded in a graphitic carbon shell synthesized by the electrospinning-magnesiothermic reduction (MTR) process. The Ni 3 C/Fe 3 C heterojunction core is encapsulated with a porous carbon shell having a large interfacial area, high conductivity, and more exposed active sites, which resulted in moderate hydrogen adsorption energy (E Hads ), increased desorption kinetics, and intriguingly efficient electron transfer. CSNi 3 C/Fe 3 C@C/NFs-600 exhibits low overpotentials (HER/OER) of 115/191 mV with a small Tafel slope of 56/53 mV dec –1 and a stability of over 60 h. The activation energy was calculated for electrolysis using CSNi 3 C/Fe 3 C@C/NFs-600 at 20.00 kJ/mol. The integrated area/number of active sites of CSNi 3 C/Fe 3 C@C/NFs-600 (4.60 × 10 –5 AV/5.730 × 10 16 ) confirmed MOOH* formation. The superaerophobicity was substantiated by fast gas bubble evolution from the catalyst surface. Using CSNi 3 C/Fe 3 C@C/NFs-600, we have produced H 2 efficiently with a lesser power consumption of 651.3 L H2 kW h –1 . The bifunctional electrolyzer of CSNi 3 C/Fe 3 C@C/NFs-600 (1.58 V) released vigorous gas bubbles compared to the benchmark electrolyzer of IrO 2 /Pt/C/NF (1.64 V) with great stability in alkaline solution. The synthetic strategy with catalyst properties demonstrated here provides perceptions into the future growth of robust bifunctional catalysts for scalable water splitting.