Preparation of high surface area nickel electrodeposit using a liquid crystal template technique

Abstract

We show in this work that template electrodeposition of nickel at room temperature from a nickel sulphamate bath prepared in a new hexagonal liquid crystalline phase of water–Triton X-100–poly (acrylic acid) results in a highly porous surface. The roughness factor value of about 3620 obtained for this coating is the highest value reported in the literature for any electrodeposited nickel. The scanning electron microscopy (SEM) and scanning tunneling microscopy (STM) pictures show the formation of porous deposit with granular features in between the pores. The single electrode double layer capacitance value measured for the deposit is 338 mF cm−2, which translates into a specific capacitance of 50 F g−1 without any post-thermal treatment of the electrode, suggesting its utility in super capacitors. Electrochemical studies using cyclic voltammetry (CV), Tafel plots and electrochemical impedance spectroscopy (EIS) and comparison of these results with some existing high surface area Ni catalysts show that the material has potential application as an excellent hydrogen evolving cathode.