Photo Catalytic Properties And First-principles Calculation Of BiOCl_xI_1-x And BiOBr_xI_1-x Solid Solution

Semiconductor photocatalytic degradation of organic pollutants is a "green,low efficiency and efficiency" strategy,in the treatment of organic dyes has a broad application prospects.Common organic pollutants are methyl orange(MO),methyl blue,phenol,formaldehyde,Rhodamine B(RhB)and so on.RhB can cause subcutaneous tissue sarcoma growth,suspected to be carcinogenic.The MO structure contains a benzene ring,and N and S heteroatoms,the molecular structure is representative.RhB and MO meet Lambert’s Law.Therefore,the degradation target of this experiment was identified as RhB and MO.Bismuth oxyhalide(BiOX)photocatalyst due to the unique open layered structure,the internal easy to produce internal electrostatic field,and for the indirect bandgap semiconductor,because the price of the top(VBM)and the baseband(CBM)is not the same cloth At the same time,there must be a certain degree of spin,which makes the photogenerated electrons and holes recombination greatly reduced.Is conducive to the improvement of photocatalytic activity,by the researcher’s favorite.This paper mainly includes the following aspects:(1)BiOX(X=Cl,Br,I)were successfully synthesized at room temperature by controlling the initial Cl/I molar ratio and Br/I molar ratio,the successful synthesis of BiOClxI1-x and BiOBrcI1-x two kinds of solid solution series,they are beautiful three-dimensional flower-like microsphere structure.The catalysts of these semiconductors exhibit different bandgap,enabling bandgap controllable synthesis.(2)The structure,adsorption,morphology,composition and optical properties of the catalysts were characterized by XRD,Raman,BET,SEM,TEM,XPS and DRS.(3)In order to evaluate the catalytic effect of photocatalysts,the RhB and MO mentioned above were used to simulate the degradation of pollutants.Since these two organic pollutants were representative and compound Lambert’s law,The photocatalytic degradation of the first-order reaction kinetics is measured by measuring the absorbance at the maximum absorption wavelength during the degradation process,and their first-order reaction kinetics k is measured to measure their ability to degrade the pollutants The The results show that BiOCl0.1I0.9 exhibits a great adsorption capacity and catalytic ability to degrade 30 mg L-1 methyl orange in the BiOClxI1-x solid solution series.The adsorption rate is 65.1%,and the reaction kinetic energy k=3.3636 h-1,and BiOCl0.9I0.1 showed high adsorption and photocatalytic degradation ability to 50 mg/L RhB,the adsorption rate was 70.0%and the reaction dynamic constant k was as high as 18.96 h-1.Photocatalytic degradation experiments show that the sample is selective for organic pollutants.Represents a different degradation mechanism.(4)The model structure is calculated and analyzed by using the plane wave super soft pseudopotential method based on density functional theory(DFT).The electron-electron interaction exchange can be used to optimize the configuration of BiOClxI1-x and BiOBrxI1-x by using PBEsol(Perdew-Burke-Ernzerhof for soild)in GGA,Generalized Gradient Approximation,and the band of crystal structure Structure and electron density were calculated.