Role of walnut ac-based Si-ZrO2: investigation of rietveld refinement, optical and electrochemical properties for pseudo-capacitor applications

Abstract In this current project, silicon substituted zirconia matrixes with the general formula of SixZr(1-x)O2 at x = 0.1–0.6, step size 0.1 have been fabricated through powder metallurgy route. All the samples have been sintered at 1200 °C for four hours in an air furnace. The structural, refinement, 3-dimensional view, functional groups, optical and electrochemical properties have been investigated using x-ray diffractometer (XRD), Rietveld refinement, diamond and Vista software, Fourier Infrared spectroscopy (FTIR), Diffuse reflectance spectroscopy (DRS), and Cyclic voltametric (CV) respectively. The XRD and Rietveld refinement exhibit sharp peaks which are matched with JCPD card no 07-0343, the single monoclinic phase is achieved in all samples. The goodness of fit clarifies the proper growth of the crystal. Furthermore, the theoretical evaluation is cross-matched with refinement data. The ATR-FTIR analysis indicates the characteristic bands of monoclinic zirconia. Due to the creation of active sites on the electrode surface, the average surface area of these oxides as determined by SEM is in the range of 58–63 m2 g−1. The lowest band gap and higher ionic conductivity values reveal the higher compatibility rate of charge carriers. The maximum specific capacitance (Csp) obtained from CV, GCD, and EIS analyses using walnut shell a.c is 903.1 A g−1, which are excellent materials for pseudocapacitive electrodes.