Electroless deposition of nanosized nickel over graphite substrate with better coating coverage and catalytic activity for fuel cell application

Abstract: Nickel nanoparticles of the size 50�60 nm were deposited on graphite particles by electroless plating. The sensitized and activated graphite powder was used as substrate precursor. The depositions of nickel and under layers of Pd and Sn on graphite particles were characterized by the Field Emission Scanning Electron Microscopy (FESEM), XRD, XPS and Energy Dispersive X-ray (EDX) techniques. The FESEM images have shown the deposition of the nickel nanoparticles. The Zeta particle analyser (ZPA) has inferred about the conductivity and average particle sizes of graphite and nickel/graphite powder. The calculated active surface area and surface coverage of Ni-deposited electrode are 0.15 A� 10�2 cm2 and 2.4409 A� 10�7 mol cm�2, respectively. The Electrochemical studies of graphite and Sn/graphite, Pd/Sn/graphite and finally the Ni�Pd/Sn/graphite were carried out using cyclic voltammetry (CV) in the potential range between �1.0 and 1.0 (V versus SCE) at the scan rate of 50 mV s�1. The electrocatalytic activity of the catalyst substance was investigated for methanol oxidation in KOH medium. Electrochemical Impedance Spectroscopy (EIS) studies of the above electrodes for methanol oxidation in 0.5 M KOH solution have shown a very small arc in the high-frequency region, which corresponds to low charge resistance and high capacitance. This implied that nickel supported on graphite would be a better electrocatalyst for fuel cell application. Graphical Abstract: Nickel nanoparticles of 50�60 nm size were deposited on graphite substrates by electroless nickel plating. The formation of Ni/graphite powders were proven by SEM, XRD, ZPA, XPES and EDX techniques. A significant electrochemical/catalytic activity of the Ni/graphite electrode was observed by impedance spectroscopy and cyclic voltammetry for methanol oxidation. Figure not available: see fulltext. © 2017, Springer Science+Business Media Dordrecht.