Tunable Fe+3 and W+6 Co-doped BiVO4 nanohybrids with efficient photocatalytic and electrochemical chemical sensing characteristics

Abstract

Metal-doped inorganic nanohybrids are platitudinous to have enormous prospects for optical, catalytic, sensing, energy, and electronic applications, owing to their inimitable properties associated with their size confinement and anisotropic geometry. In this regard, the present study is focused on the fabrication of tunable Fe+3 and W+6 co-doped BiVO4 nanohybrids for photocatalytic and electrochemical sensing applications. We synthesized Bi1-xFexV1-yWyO4 (BFVWO) nanostructures with varying compositions (x = 0.0, 0.25; y = 0, 0.01, 0.02, 0.04, and 0.06) using a sonication-assisted hydrothermal method. The developed nanostructures were physiochemically characterized by XRD, SEM, EDX, FTIR, XPS, UV–Vis, BET, PL, TOC, EPR, EIS, and CV spectroscopy measurements to investigate the phase purity, morphology, chemical purity, and optical properties. The physicochemical characterization revealed reduced crystallite size (from 89 to 82 nm), a tunable optical bandgap (from 2.42 to 2.13 eV), and an increased surface area with co-doping content. Among the samples, the Bi0.75Fe0.25V0.96W0.04O4 (BFVWO-4) nanohybrid exhibited remarkable potential for photocatalytic decomposition/degradation of water contaminants (CR and MO azo dyes) and showed an outstanding response against the electrochemical detection of methanol in a K2SO4 background. This study emphasizes the significance of selecting an appropriate electrolyte solution for accurate methanol sensing applications. BFVWO-4 exhibited superior analytical parameters compared to previously reported methanol sensors, with exceptional sensor sensitivity and a low limit of detection (LOD) at (S/N = 3) of 0.1 μM with an extended dynamic range spanning from 0.01 to 1 mM. It also offers insights and emerges a novel commencement for the prospective potential of Fe+3 and W+6 co-doped BiVO4 with exceptional photocatalytic degradation of water contaminants and outstanding sensitivity for methanol detection. These attributes position it as a prospective candidate for future applications in environmental and clinical monitoring.