Study on overpotential of the electrochemical hydrogen storage of multiwall carbon nanotubes

Multiwall carbon nanotubes (MWNTs) hydrogen storage electrode was prepared by composite electro-deposition (CED) method with sulfate electrolyte. The content of multiwall carbon nanotubes is 22.45% (w/w) in the MWNTs electrode. The discharging curves of electrochemical hydrogen storage show that the discharging voltage of the MWNTs–Ni electrode prepared by CED method is higher than that of mixing copper or nickel powder method, and cyclic voltammogram indicates that the peak potential of hydrogen oxidation is at - 706 mV (vs Hg/HgO). Both methods of MWNTs electrodes prepared by CED and mixed with metal powder have different electrochemical characteristics of hydrogen oxidation. Nickel electrodeposited on MWNTs improved the catalysis efficiency of nickel for the electrochemical oxidation of hydrogen.