FABRICATION OF BISMUTH OXYIODIDE (BiOI) PHOTOELECTRODES VIA SOLVOTHERMAL METHOD FOR PHOTOELECTROCHEMICAL APPLICATIONS

Abstract

Bismuth oxyiodide (BiOI) thin films were successfully synthesized from Bi(NO₃)₃ and KI precursors via a solvothermal method in an ethylene glycol ((CH₂OH)₂) medium. In this study, the morphology and thickness of BiOI nanosheets were uniformly formed on conductive FTO substrates at different temperatures. X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM) were employed to investigate the crystal structure and surface morphology of the BiOI films. UV–vis–NIR absorption spectra were measured using spectroscopy in the wavelength range of 300–700 nm to clarify the optoelectronic properties of the BiOI photoanode. The photoelectrochemical characteristics of the electrode were studied through Mott-Schottky (M-S) analysis and linear sweep voltammetry (LSV) using a three-electrode electrochemical system. The electrode prepared with a 30 mM Bi(NO₃)₃ precursor concentration exhibited a maximum photocurrent density of 0.35 mA·cm⁻², demonstrating the material's potential for photoelectrochemical applications.