Preparation, Modification And Photocatalytic Properties Of BiOBr

Photocatalytic technology can use light to excite semiconductor materials to decompose water and oxidize water pollutants,which has great application prospects for renewable energy replacement and environmental protection.In order to effectively utilize the clean and rich solar energy,searching for efficient photocatalysts that can respond to visible light has becoming a research hotspot.The practical application of visible light responsive catalysts is of great significance in solving existing energy shortages and environmental pollution problems.In this paper,coprecipitation method was used to synthesize the catalyst.The BiOBr catalyst was the core,a series of studies were carried out to design and modify BiOBr photocatalyst with high photocatalytic activity under visible light.The main research contents are as follows:?1?BiOBr was synthesized by a simple co-precipitation method.And based on metal ion doping and non-metal ion dopingion,BiOBr_xCl_1-x and BF complexes were synthesized respectively.Meanwhile the effects of Cl^-and Fe³⁺addition on the photocatalytic performance of BiOBr were investigated.The results were characterized by XRD,SEM and UV-vis.The reason why ion doping improves the photocatalytic performance of BiOBr was systematically analyzed.Photocatalytic test results showed that the degradation rates of methyl orange solution were 95.81%and 98.90%respectively,when BiOBr_0.5Cl_0.5 and BF-10%were irradiated for 4 hours under visible light.?2?BiOBr/CeO₂ heterojunction was constructed by one-step method.XRD,UV-vis and BET were used to characterize the composites.The results showed that the composites formed heterojunction structure.BiOBr/CeO₂ broadens the absorption edge of BiOBr and increases the specific surface area.The existence of heterojunctions accelerates the separation of photogenerated electron-hole pairs and improves photocatalytic degradation.In the experiment of degradation of methyl orange,BC-20%in visible light,within 120minutes,the degradation rate reached 98.19%,which was twice that of pure BiOBr,and the photocatalytic activity was significantly improved.?3?NaBH₄ was used as reductant to reduce noble metal ions,and a series of noble metal-supported BiOBr complexes were prepared.The effects of different precious metal species modification on the photocatalytic performance of BiOBr were investigated by means of modern characterization methods XRD,TEM,UV-vis,etc.The precious metal Pd was selected to investigate the effect of loading on performance.The results show that the noble metal nanoparticles are successfully deposited on the BiOBr.The noble metal/BiOBr composite accelerates photocarrier separation and improves reactivity The photocatalytic test results showed that the methyl orange solution could be completely degraded under visible light after 150 minutes of illumination,and had good cyclic stability.