Microwave-assisted synthesis of ZnO decorated acid functionalized carbon nanotubes with improved specific capacitance

Abstract

The fabrication and testing of new materials for energy storage applications is slowly gaining impetus amidst the constantly developing technological sector. Carbon-based materials have been extensively used for their high surface area, conductivity and good mechanical properties. Here, acid functionalized carbon nanotubes and its ZnO composite have been prepared using a facile microwave assisted technique and their electrochemical performances have been compared. The samples have been characterised using spectral techniques such as UV–Visible, FTIR and Raman spectroscopy. Their surface morphology has been studied using Scanning electron microscopy. X-ray diffraction analysis has been performed on the samples to further characterise the synthesised nanomaterials. Their electrochemical properties were investigated using cyclic voltammetry, chronopotentiometry and AC impedance techniques. The samples exhibit enhanced specific capacitance and good cycling stability. A high value of specific capacitance was achieved for CNT-COOH/ZnO thereby reinforcing the improvement of electrochemical characteristics of acid functionalized carbon nanotubes through composite formation.