NiFe@CN/VS ₂ /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 H 2 production and industrialize its application. Among them, a 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 VS 2 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[Formula: see text]C catalyst exhibited an overpotential of 146[Formula: see text]mV at 10[Formula: see text]mA cm[Formula: see text] and a Tafel slope of 48.3[Formula: see text]mV dec[Formula: see text], substantially lower than NiFe@CN/CC−400[Formula: see text]C (335[Formula: see text]mV, 70.2[Formula: see text]mV dec[Formula: see text] and commercial RuO 2 (270[Formula: see text]mV, 57.5[Formula: see text]mV dec[Formula: see text], with excellent stability over 20[Formula: see text]h of operation. The DFT calculations showed that the 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.