Morphology tailoring and enhanced electrochemical properties of Cd–Zn co-doped NiO nanorods for high performance supercapacitor

Abstract A systematic approach has been introduced to synthesize Cd–Zn co-doped NiO nanostructures with different ratios such as Cd0.07Zn0.03NiO, Cd0.05Zn0.05NiO, Cd0.03Zn0.07NiO and Cd0.01Zn0.09NiO for supercapacitor applications. The XRD studies has confirmed the phase purity with average crystallite size of 40 nm. The SEM characterization has shown that the morphology of nanostructures was tuned from particles to nano-rods structure with increasing the at. % concentration of Zn doping. Optical properties revealed that band gap and recombination rate have strong co-relation with specific capacitance. The CV results have confirmed the pseudocapacitive nature of the as prepared nanostructures and maximum specific capacitance (1485.19 Fg-1) was measured for Cd0.03Zn0.07NiO which is superior than numerous reported values of NiO. The GCD results of Cd0.03Zn0.07NiO performed at 1 A/g scan rate, exhibited excellent charging-discharging ability with high cyclic retention of 82.8%. High capacitance and superior stability of Cd0.03Zn0.07NiO material indicate it as a potential candidate for supercapacitor applications.