NiFe@CN/VS₂/CC ternary heterojunction as a high-performance electrocatalyst for oxygen evolution reaction

The development of low-cost and high-performance OER catalysts is an important way to reduce the effective cost of H2 production and industrialize its application. Among them, heterojunction consists of two semiconductors and relies on interfacial engineering to accelerate electron transfer. In this study, ternary heterojunction NiFe@CN/VS 2 /CC composites were prepared by depositing VS2 and NiFe PBA successively with carbon cloth as the carrier template, followed by high-temperature annealing and calcination, and the oxygen evolution reaction (OER) performance of this composite catalyst was systematically investigated. Electrochemical evaluation showed that the NiFe@CN/VS 2 /CC-400°C catalyst exhibited an overpotential of 146 mV at 10 mA cm −2 and a Tafel slope of 48.3 mV dec −1 , substantially lower than NiFe@CN/CC-400°C (335 mV, 70.2 mV dec −1 ) and commercial RuO2 (270 mV, 57.5 mV dec −1 ), with excellent stability over 20 hours of operation. The DFT calculations showed that the oxygen evolution reaction (OER) of NiFe@CN/VS 2 was much more stable than that of the NiFe@CN and VS 2 in all four steps. steps all require smaller potentials. The formation of heterojunction reduces the Fermi energy level of VS 2 , adjusts the electronic structure, enlarges the interlayer spacing, and generates abundant active sites at both the edge and basal surfaces. This study provides a feasible way to design inexpensive and high-performance OER electrocatalyst materials.