A comparative study has been conducted on the cathode electrolysis plasma emission spectra recorded during the plasma-assisted electrochemical exfoliation of black phosphorus and graphite under maximally identical experimental conditions. It has been found that in the case of black phosphorus exfoliation, the concentration of active intermediates (OH radicals and O atoms) in electrolytic plasma is significantly lower than that in the case of the graphite electrode. It has been assumed that this effect is due to the fact that the rate of interaction of the above intermediates with the synthesized phosphorene structures is significantly higher than the rate of interaction with graphene-like particles. This assumption has been confirmed by the detection of a significantly higher oxygen content in the exfoliation products of black phosphorus than the oxygen content in the synthesized carbon nanoparticles.