Sn-doped BiOCl for photoelectrochemical activities and photocatalytic dye degradation under visible light

Abstract

In this work, bismuth oxychloride (BiOCl) and Sn-doped BiOCl (SBCl) with improved visible light photocatalytic activity were synthesized via the co-precipitation method. The XRD analysis determined the tetragonal phase of BiOCl, 1 %, 5 %, and 10 % SBCl. The crystallite sizes were in the range of 20–34 nm. These results confirmed that the Sn ion was successfully incorporated into the BiOCl lattice. This was further confirmed by FT-IR and Raman analysis. The optical properties, such as the band gap energy, were studied using UV–vis DRS. It was found that doping BiOCl with Sn has a minor effect on the band gap tuning. BET shows that the SBCl samples have acquired a larger specific surface area (14.66–42.20 m2/g) than BiOCl (13.49 m2/g). The photocatalytic performance showed that SBCl samples have higher photocatalytic activity than BiOCl in degrading Rhodamine B (RhB) dye under visible light irradiation. Among the SBCl samples, 5 % SBCl exhibited the highest photocatalytic efficiency which degraded 91.2 % of the RhB dye in 60 min. Moreover, the photoelectrochemical activities of the as-synthesized BiOCl and SBCl were investigated using linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) in the dark and under visible light irradiation. Both studies showed that SBCl exhibits enhanced photoelectrochemical activities than BiOCl. Hence, it can be suggested that SBCl possesses visible light active properties and can be potentially used as a photocatalyst and photoelectrode material.