Synthesis and characterization of pure BiVO ₄ and zirconium-doped BiVO ₄ nanoparticles for supercapacitor and photocatalytic performance

Abstract This study presents the wet-chemical synthesis and characterization of Zr-doped BiVO 4 ((Zr) x -(BiVO 4 ) 1-x , where x = wt.0 %, wt.2 %, wt.4 %, wt.6 %) nanoparticles, showcasing dual functionality in boosting supercapacitor applications and photocatalytic efficiency. X-ray diffraction (XRD) analysis verified zirconium incorporation into the BiVO 4 lattice without altering its monoclinic crystal structure. Field Emission Scanning Electron Microscopy (FE-SEM) analysis revealed significant morphological alterations with varying zirconium concentrations, emphasizing variations in particle shape and size. Energy Dispersive X-ray Analysis (EDAX) validated the stoichiometric composition and confirmed the precise integration of zirconium into the BiVO 4 lattice. Fourier Transform Infrared Spectroscopy (FT-IR) confirmed vibrational modes and X-ray Photoelectron Spectroscopy (XPS) revealed active sites and oxidation states driving the dual functionality nanomaterials. Diffuse Reflectance Spectroscopy (DRS) indicated that the band gap values decrease with an increase in dopant concentration. Raman spectra showed a characteristic peak at 827 cm −1 , confirming the successful formation of BiVO 4 . The Zr-doped electrode achieved a specific capacity of 47 C g −1 , surpassing among all other electrodes. Optimal wt.6 % Zr doping achieved 91.14 % methylene blue removal within 120 min of light exposure. Pseudo-first-order kinetics and reusability tests further confirmed that Zr incorporation enhances long-term stability and photocorrosion resistance through synergistic effects.