Preparation And Photocatalytic Properties Of (Ag,Cu)/BiOBr As Visible Light Compound Photocatalyst

Scientists have gradually paid attention to energy and environment issues in the 21 st century,including the degradation of environmental pollutants.Photocatalytic technology become one of the important methods for dealing with the challenge.Semiconductor photocatalyst is the heart of photocatalytic technology.BiOBr becomes more and more popular due to its unique layered and suitable band gap.However,application has been limited because of the lower solar energy utilization rate.Therefore,we adopt different methods to improve the BiOBr photocatalytic efficiency in this paper.The detailed works as follows:Firstly,Ag/BiOBr photocatalyst was studied.Ag/BiOBr catalysts was prepared by using ultraviolet light deposition method,ultrasonic-assisted-xenon lamp light deposition and liquid hydrazine hydrate reduction method,respectively.The prepared samples were characterized by UV-vis DRS,XRD,SEM,TEM/HRTEM and SPS.The photocatalytic activities were analyzed.No matter what kind of preparation method of catalyst was used,the surface plasmon resonance(SPR)peak of Ag was clearly observed at about 500 nm in the visible light region.Visible light response range of BiOBr was broadened effectively and the visible light photocatalytic efficiency of BiOBr was enhanced.The results show that preparation methods had important influence on the catalytic performance for final samples.Secondly,Cu/BiOBr photocatalyst was studied.Cu/BiOBr was prepared by using liquid hydrazine hydrate reduction method and ultrasonic assisted Fe metal reduction method,respectively.The reaction temperature,pH,the speed of dropping of CuCl2,the amount of N2H4·H2O and the mole ratio of Cu and BiOBr were discussed in terms of Cu/BiOBr synthesized by liquid hydrazine hydrate reduction method.And ultrasonic time,ultrasonic power,the mole ratio of Cu and BiOBr were discussed in terms of Cu/BiOBr synthesized by ultrasonic assisted Fe metal reduction method.The crystalline structure,morphology,photoabsorption performance,photovoltaic property and stable performance were characterized.The results show that deposition of Cu nanoparticles expanded the light absorption of BiOBr to visible light area,and photocatalytic efficiency were improved.Theoretical simulation results show that the Cu/BiOBr energy band was reduced.The samples degraded the organic dyes and reflected its selectivity.Thirdly,(Ag,Cu)/BiOBr photocatalyst was studied.(Ag,Cu)/BiOBr catalysts were prepared by using liquid hydrazine hydrate reduction method.The crystal structure,morphology,photoabsorption performance and photovoltaic property were characterized.Results show that the deposition of Cu and Ag nanoparticles(NPs)effectively broadened visible light response range of BiOBr,enhanced the photocatalytic efficiency of BiOBr.(Ag,Cu)/BiOBr,which the molar of metal and BiOBr is 0.06:1,and the molar ratio of Cu and Ag is 2:1,was superior to the single load in photocatalytic degradation of MO.The photocatalytic efficiency increased by means of silver partially replaced by copper,at the same time,the preparation cost of catalyst has decreased.