Preparation And Properties Of BiOBr Based Photocatalytic Materials

Photocatalytic technology,as a green strategy that can effectively improve and solve environmental pollution,has shown great application potential in pollutant treatment and energy conversion.The preparation of nanomaterials with high catalytic activity has always been the main research direction.BiOBr materials have attracted the attention and favor of researchers because of their suitable bandgap value and unique 2D layered structure.But the single BiOBr still remain visible absorption capacity and electronic-hole to compound of high rate of significant problems.In this paper,BiOBr composites were synthesized by improving the light absorption capacity and the electron-hole pair separation rate,so as to improve their photocatalytic activity.In this paper,β-SiC/BiOBr and Pt/I-BiOBr composites were prepared based on BiOBr.The structure,microstructure and photoelectrochemical properties of the catalyst were analyzed and tested.The possible mechanism of the combination ofβ-SiC and BiOBr was discussed,and the role of iodide ion and Pt nanoparticles in the composite photocatalyst was discussed.The main research contents are as follows:(1)Study on the photocatalytic activity ofβ-SiC/BiOBrIn this paper,a novel photocatalyst ofβ-SiC/BiOBr was prepared by hydrolysis-calcining method.The structure and photochemical properties of the composite catalyst were investigated by means of a series of characterization tests.The results confirmed the successful combination ofβ-SiC and BiOBr.In addition,investigated its photocatalytic activity by experiments on BPA under visible light.The experimental results showed that the photocatalytic activity of BiOBr could be enhanced by the addition ofβ-SiC to a certain extent,and the catalytic activity reached the optimum after the addition of 2.77 wt%β-SiC.In addition,the photocatalytic degradation activity was still high after 4 cycles under visible light.By means of capture agent experiment,ESR,DRS and other detection methods,we can speculate that p-n heterojunction is formed betweenβ-SiC and BiOBr,which promotes the transfer ability of electrons and holes,inhibits the photogenerated electron-hole recombination rate,and improves the catalytic ability of catalysts in visible light.(2)Study on the photocatalytic activity of Pt/I-BiOBrThe Pt/I-BiOBr composite photocatalyst was prepared by hydrolyzation-calcination assisted photoreduction.The structure and morphology were analyzed by means of XRD,XPS and SEM to proved the successful combination of Pt,I~-and BiOBr.The photocatalytic activity of the composites was investigated by degrading of BPA under visible light,and the experimental results shown that Pt/I-BiOBr exhibited the highest photocatalytic activity,which was 5.8,1.5 and 1.3 times of BiOBr,I-BiOBr and Pt/BiOBr,respectively.Through PC,PL and DRS tests,it has been confirmed that I~-doping can broaden the visible light absorption range of BiOBr,and the Pt loading can promote the separation of BiOBr photoelectron-hole pairs and provide more reaction sites for the reaction.The previous synergistic effect of the two aspects greatly enhanced the photocatalytic activity of BiOBr.