Preparation and property for hydrogen evolution of AC ( activated char) /Ni-Co composite electrode materials

The AC/ Ni-Co composite elect rode was prepared by means of composite-elect rodeposition. The surfacemorphology and microst ructure of the elect rode coating were observed by XRD and SEM. The result s show that thecomposition of AC does not change the crystal st ructure of the Ni-Co alloy elect rode , but the surface roughness andreal surface area of the coatings increase. Catalytic abilities for hydrogen evolution of different elect rodes in1 mol·L^-1 NaOH solution were evaluated on the basis of elect rochemical steady-state polarization curves andalternating current impedance spect rum technology. The result s show that the AC/ Ni-Co composite elect rode ( theamount of AC is 3 g·L^-1 in bath ) is catalytically more active than the Ni and Ni-Co alloy elect rode. The polarizationpotential for hydrogen evolution of the composite elect rode is 230 mV lower than that of the Ni elect rode and is140 mV lower than that of the Ni-Co alloy elect rode at the current density of 0. 03 A·cm^-2 . The apparent exchangecurrent density of the composite elect rode is 30 times as much as that of Ni elect rode , and 6 times that of the Ni-Coalloy elect rode. The increasing catalytic activity for hydrogen evolution of the AC/ Ni-Co composite elect rode ismainly due to the increase in the real surface area of the elect rode.