Self-assembled BiVO4 nanorods: A fascinating electrode material for highly efficient pseudocapacitors and electrochemical nitrite sensors

Abstract

The design of new assembles at nanoscale is vital in promoting the energy - power density of storage devices. Herein, we have reported the excellent electrochemical properties of novel self - assembled BiVO4 nanorods fabricated by hydrothermal route. The as prepared self - assembled BiVO4 nanorods loaded electrode is probed under various electrochemical characterizations in aqueous electrolyte (2 M NaOH) and found that the electrode has delivered very high capacitive charge storage of 90% (which is analyzed first time for BiVO4 nanostructures) at a scan rate of 100 mV s−1, very high specific capacitance (798 F g−1 at 1 A g−1 and 866 F g−1 at 10 mV s−1 respectively) and excellent cyclic retention (89% of the initial capacitance after 4000 cycles). The self - assembled BiVO4 nanorods based asymmetric supercapacitor configuration has exhibited an extended potential window and demonstrated 98% of the capacitive charge storage, very high specific energy and power density (106 Wh kg−1 and 4200 W kg−1 respectively). Furthermore, as prepared self - assembled BiVO4 nanorods modified electrode tested for nitrite sensing in water based solution (0.1 M PBS) prove highly sensitive and selective sensor which exhibited a higher sensitivity of 56 μA μM−1 cm−2 in the wider range from 1 to 30,000 μM (R2 = 0.99923). The promising electrochemical properties of the electrode can be attributed to the faster ionic insertion/desertion in novel self - assembled BiVO4 nanorods by increase in the number of pore sites due to the presence of ultrafine nanoparticles in basic assembly. This work paves a way for the enhancement of electrochemical performances of energy storage devices.