Characterization of the visible-light-driven BiVO4 photocatalyst synthesized via a polymer-assisted hydrothermal method

BiVO₄ photocatalyst was synthesized by a polymer-assisted hydrothermal method at different temperatures and reaction times. Sodium carboxymethylcellulose was used in order to assist the formation of BiVO₄ oxide. The resulting samples were characterized by X-ray powder diffraction, scanning electron microscopy, diffuse reflectance spectroscopy, and adsorption–desorption N₂ isotherms (BET). The predominant BiVO₄ phase of the system within the 160–200 °C range was the monoclinic crystalline structure, which was obtained in pure form only under certain experimental conditions. Short reaction times promoted the formation of linear arrays of BiVO₄ formed by particles with irregular form ranging in size between 100 and 200 nm. The photocatalytic activity of BiVO₄ samples was evaluated in the degradation of rhodamine B (rhB) under visible-light irradiation. The samples exhibited a higher activity when they were synthesized at higher temperatures and longer times of hydrothermal reaction. The total organic carbon analysis of a sample irradiated for 100 h revealed that mineralization of rhB by the BiVO₄ photocatalyst is feasible.