METHOD FOR OBTAINING OXIDE LAYERS ON THE SURFACE OF A CARBON FIBER MATERIAL UNDER POLARIZATION BY ALTERNATING ASYMMETRIC CURRENT Russian patent published in 2022 - IPC C25D3/02 

FIELD: electrochemistry.

SUBSTANCE: invention relates to the field of technical electrochemistry. The invention relates to a method for producing oxide layers on the surface of a carbon fiber material, consisting in the fact that the pre-prepared surface of a working electrode made of carbon fiber material is polarized with an alternating asymmetric current of industrial frequency 50 Hz on both sides in an electrolyte solution containing salts of molybdenum, cobalt, iron, boric and citric acid, stainless steel is used as counter electrodes, differing in that the electrolyte additionally contains manganese sulfate and cobalt chloride at the following component ratios (g∙l^-1): ammonium heptamolybdate ((ΝΗ₄)₆Μο₇O₂₄⋅4H₂O) 20.0-40.0, cobalt sulfate (CoSO₄⋅7H₂O) 80.0-100.0, iron sulfate (FeSO₄⋅7H₂O) 8.0-10.0, manganese sulfate (MnSO₄⋅5Η₂O) 20.0-30.0, cobalt chloride (CoC1₂⋅6H₂O) 10.0-14.0, boric acid (H₃BO₃) 20.0-30.0, citric acid (C₆H₈O₇) 2.0-4.0 at pH=3.5-4.5, polarization by alternating asymmetric current is carried out at values of the asymmetry coefficient β=1.8÷2.2, at temperature 60°C; the electrolysis time is 40 minutes, with simultaneous co-deposition of oxide compounds of molybdenum, cobalt, manganese, iron.

EFFECT: use of the proposed method makes it possible to reduce energy consumption, since the average current density at a voltage of 40 V was 0.70 A∙dm^-2; to obtain oxide layers on the surface of the carbon fiber carrier; to realize a uniform distribution of oxide compounds over the depth of the carbon fiber material; to increase the content (wt. %) of molybdenum, providing the formation of electrochemically active phases; to ensure high adhesion of the oxide layers to the surface of the carbon fiber carrier, thereby avoiding the addition of a polymer binder capable of swelling and negatively affecting the electrochemical characteristics of such materials.

1 cl, 2 ex