Visible light responsive heterostructured α-bi2 o3/zno doped β-bi2 o3 photocatalyst for remediation of organic pollutants

Abstract

Novel visible-light active α-Bi2 O3/ZnO doped β-Bi2 O3 (ZB) photocatalyst was synthesized at different temperatures 400°C (ZB4), 500°C (ZB5), and 600°C (ZB6) by modified sol–gel method. The struc-tural, morphological, compositional, and optical properties of synthesized photocatalyst were characterized using X-ray powder diffraction, field emission scanning electron microscopy, energy dispersive X-rays spectroscopy, Fourier transform infrared spectroscopy, and UV-vis spectroscopy. With an increase in calcination temperature, the bandgap of the prepared photocatalyst increases, and metastable β-phase Bi2 O3 changes to α-phase. The photocatalytic activity was evaluated using Alizarin Red S (ARS) as a model organic compound. The rate of degradation was estimated from residual concentration spectrophotometrically. The results revealed that with an increase in calcina-tion temperature, the photocatalytic activity of synthesized ZB photocatalyst decreases. Maximum decolorization efficiency (88%) was shown by the photocatalyst prepared at 400°C which is 29% and 37% higher than that of photocatalyst prepared at 500°C and 600°C, respectively.