Fe(Ⅲ) ions enhanced catalytic properties of (BiO)2CO3 nanowires and mechanism study for complete degradation of xanthate

Abstract

The wire-like Fe3+-doped (BiO)2CO3 photocatalyst was synthesized by a hydrothermal method. The photocatalytic property of Fe3+-doped (BiO)2CO3 nanowires was evaluated through degradation of sodium isopropyl xanthate under UV–visible light irradiation. The as-prepared Fe3+-doped (BiO)2CO3 nanowires were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), UV–visible diffuse reflectance spectroscopy (UV–vis DRS), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) in detail. The results of XRD showed that the crystallinity of (BiO)2CO3 nanowires decreased when Fe3+ ions were introduced into the solution system. XPS results illustrated that xanthate could be absorbed on the surface of Fe3+-doped (BiO)2CO3 nanowires to produce BiS bond at the beginning of the reaction, which could broaden the visible light absorption. FTIR spectra confirmed the formation of SO42− after photocatalytic decomposition of xanthate solution. The Fe3+-doped (BiO)2CO3 nanowires showed an enhanced photocatalytic activity for decomposition of xanthate due to the narrower band gap and larger BET surface area, comparing with pure (BiO)2CO3 nanowires. By the results of UV–vis spectra of the solution and FTIR spectra of recycled Fe3+-doped (BiO)2CO3, the xanthate was oxidized completely into CO2 and SO42−. The photocatalytic degradation process of xanthate followed a pseudo-second-order kinetics model. The mechanism of enhanced photocatalytic activity was proposed as well.