Post annealing temperature-dependent morphological and electrochemical properties of copper hydroxide thin film electrodes obtained by anodization of copper
Anodization of copper substrates was made in 1 M aqueous sodium hydroxide solution to prepare copper hydroxide thin films. The prepared samples (at 0.9 V) were annealed in air for 1 h by varying the annealing temperature from 523 to 673 K. XRD study confirms the orthorhombic crystal structure for copper hydroxide, whereas cubic to monoclinic crystal structure transformation was observed for copper oxide with increasing annealing temperature. The increase in granular size of copper oxide with temperature was clearly endorsed from morphological study. Electrochemical study reveals the pseudocapacitive behavior for the sample annealed at 598 K with optimum-specific capacitance of 6000 F/g at the scan rate 2 mV/s in 1 M NaOH. The Specific energy, Specific power, and Columbic efficiency (η) were calculated by using chronopotentiometric technique. Electrochemical impedance spectroscopy carried out in the frequency range of 1 mHz–1 MHz gives internal resistance which is about 1.75 Ω/cm2. The Randles equivalent circuit and its circuitry parameters are reported.
KeywordsSpecific Capacitance Cu2O Copper Oxide Deposition Potential Thin Film Sample
The authors thank the DST-SERB for providing financial support through the project scheme 2014/DST-SERB/4688.
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