The effect of various capping agents on V2O5 morphology and photocatalytic degradation of dye

Abstract

Different morphologies of vanadium pentoxide (V2O5) nanostructures were successfully obtained using various capping agents including polymer polyvinyl pyrrolidone (PVP), polysorbate 80 (Tween 80) and ethylene diamine tetra acetic acid (EDTA), through a hydrothermal process. Different morphologies of V2O5 were achieved by changing capping agent or mineralizer. The characterization of various obtained nanostructures was examined applying scanning electron microscopy (SEM), UV–Vis absorption, X-ray powder diffraction (XRD), UV–Vis diffuse reflectance spectroscopy (DRS) and Brunauer–Emmett–Teller (BET). The photocatalytic activity of the samples was investigated according to methylene blue removal (MB) under a solar simulator lamp. Based on the experiments, the photocatalytic performance of V2O5 can be improved by utilizing various capping agents as a result of band gap reduction and the improvement of electron–hole separation. DRS spectra revealed that absorption edge of samples was in the visible region of spectrum. Also, the produced catalysts were employed to degrade methylene blue under simulated sunlight irradiation. The impact of different operating parameters including solution pH, catalyst dosage and initial MB concentration on degradation efficiency was also investigated. Optimization investigation was fulfilled with the method of response surface methodology (RSM) employing the Box–Behnken design (BBD). Consequently, the maximum degradation percentage of 96.97% was achieved using PVP–V2O5 under optimum operating condition of pH 9, catalyst dosage = 0.66 g/L and initial MB concentration = 10 ppm.