Difunctional electrocatalyst with heterostructure nickel cobalt nitride nanosheet array and preparation and application of difunctional electrocatalyst

The preparation method comprises the following steps: (1) dissolving a soluble nickel salt, a soluble cobalt salt, urea and ammonium fluoride in deionized water to form a uniform solution, transferring the uniform solution into a reaction kettle containing carbon cloth, carrying out a hydrothermal reaction, washing the reaction kettle with water, and drying the reaction kettle to obtain a nickel-cobalt nitride nanosheet array; a nickel-cobalt bimetallic precursor loaded on the carbon cloth is obtained; and (2) placing the nickel-cobalt bimetallic precursor loaded on the carbon cloth in an ammonia atmosphere for high-temperature nitridation to obtain a target product, namely the difunctional electrocatalyst. Based on an in-situ growth strategy and an array structure of the heterojunction nanosheets, rapid electron transfer is facilitated, more active sites are exposed, electron interaction of a heterojunction interface and a synergistic effect of different components are facilitated, and therefore the catalytic activity of the material is facilitated.