Facile synthesis of WO3.H2O nanostructures for efficient photocatalytic and electrochemical properties

Abstract

WO₃·H₂O nanostructures have fascinated momentous consideration due to their distinctive properties such as small bandgaps as compared to WO₃, tunable morphology, and distinct photocatalytic properties. These nanostructures were successfully fabricated by the hydrothermal method (by varying solvent volume) and characterized by X-ray diffraction (XRD), EDX, and FESEM to analyze the crystallinity, chemical composition, and morphology which indicated the average size of 140–190 nm. The presence of O-W-O and O = W chemical bonds, and O–H stretching vibrations in FTIR spectrum demonstrate the fabrication of WO₃·H₂O nanostructures. The UV–Visible spectroscopy and PL study were conducted which presented that the optical bandgaps lies in the range (2.16–2.5 eV) which were beneficial for photocatalytic activity. To assess the photocatalytic response, rhodamine B, methyl orange, reactive orange 16 dyes and additionally industrial wastewater were used. It was noted that the photodegradation efficiency of sample 1 was higher than other samples for all dyes. The percentage degradation for RhB (99.5 %), MO (97.5 %), RO16 (88.7 %), and IW (99.5 %) and the reaction rate constants are RhB (0.0768 min⁻¹), MO (0.03991 min⁻¹), RO16 (0.02363 min⁻¹), and IW (0.0744 min⁻¹). The sample 1 have 1.5 times higher photocatalytic properties than all other samples, attributed to its lowest bandgap 2.16 eV, and lower charge carriers recombination rate. Moreover, the electrochemical properties of WO₃·H₂O nanostructures were also evaluated presenting a specific capacitance of 1209F g⁻¹. This analysis highlights their potential in environmental remediation and supercapacitor applications.