The Contrastive Research in the Photocatalytic Activity of BiOBr Synthesized by Different Reactants

BiOBr nanoplates, marked as α‐BiOBr and β‐BiOBr, were synthesized via hydrothermal method using cetylpyridinium bromide (CPB) and NaBr as reactants, respectively. X‐Ray Diffraction (XRD), transmission electron microscope (TEM), N2 adsorption/desorption, UV‐visible diffuse reflectance spectroscopy (UV‐Vis DRS), and cyclic voltammetry (CV) were employed to characterize the obtained BiOBr. The results showed that α‐BiOBr and β‐BiOBr can absorb visible light and both the band gaps of them were about 2.76 eV. Under visible light irradiation, the photodegradation of organic dye sulforhodamine (SRB) and salicylic acid (SA) using α‐BiOBr and β‐BiOBr as the catalysts was carried out. The reaction kinetic constants of the degradation of SRB by α‐BiOBr and β‐BiOBr were 0.00602 min−1 and 0.0047 min−1, respectively, which indicated that the photocatalytic activity of α‐BiOBr was higher than that of β‐BiOBr. The UV‐Vis DRS and total organic carbon (TOC) were also monitored, and the TOC removal rate of α‐BiOBr and β‐BiOBr was 86% and 48%, respectively. At the same time, hydrogen peroxide (H2O2) and active radicals were measured and analyzed, which showed that the main active species was  ∙OH during the photocatalytic reaction.