Effect of pH in the bismuth vanadate nanorods for their supercapacitor applications

The different pH-varied bismuth vanadate nanorods have been synthesized through a solvothermal method and utilized for XRD, HRTEM, SEM and electrochemical studies. The XRD spectra of BV-5 and BV-7 samples show the monoclinic structure. Both electrodes show rod-like morphology. Also, when the pH 7 the bismuth oxide shows large size nanorods compared with pH 5. The interspacing distance of the samples were reduced while the pH was increased. The electrochemical performance of the prepared BV-5 and BV-7 shows higher capacitance values of 235 and 167 F/g for BV-5 and BV-7 electrodes, also these electrodes show a maximum energy density value of 13.4 and 18.8 Wh/kg and related power density values are 720 and 867 W/kg, respectively. The power density value of the BV-7 electrode was increased without affecting the energy density value. Moreover, the cyclic retention of BV-7 shows 93 % at the 1000th cycle. Also, the capacitance and Rct values of BV-7 electrode are comparatively higher than pure BV-5 electrode.