Nitrogen-doped few-layer graphene structures were synthesized by the plasma-assisted electrochemical exfoliation of graphite and were used to prepare composites with phosphorene structures obtained as a result of ultrasonic exfoliation of a black phosphorus porous electrode with cobalt preliminarily deposited on it. The catalytic activity towards hydrogen evolution reaction of few-layer graphene and phosphorene structures, as well as their mixtures was studied, and mixed electrocatalysts was shown to demonstrate the highest activity towards hydrogen evolution reaction.