Synthesis Of Bismuth-based Semiconductor And MOF Composite Photocatalysts And Their Degradation Of Pollutants

Metal-organic frameworks（MOFs）are three-dimensional porous materials with periodic network structure formed by the bonding of organic ligands to metal ions or metal clusters through coordination bonds.As a new type of layered material,bismuth semiconductor material exhibits excellent photocatalytic performance due to its unique layered structure.This paper mainly studies BiOBr/ZnFe-MOF,Fe-BiOCl/Fe-MOF,Bi-TDC-PVP and BiOBr/Bi-TDC,and the main work is as follows:（1）Bimetallic ZnFe-MOF was synthesized by solvothermal method using Zn²⁺and Fe³⁺as metal sources and 1,4-terephthalic acid（H₂BDC）as ligands.The synthesized ZnFe-MOF was added to the ethylene glycol solution containing Bi（NO₃）₃·5H₂O and CTAB and solved into a 3D wool-ball photocatalytic material with a 3D wool ball structure.The results show that the degradation result of rhodamine B（RhB）solution can reach 99.0%after 90 min of visible light irradiation.（2）Ferric chloride hexahydrate（FeCl₃·6H₂O）,bismuth nitrate pentahydrate Bi（NO₃）₃·5H₂O and 1,4-terephthalic acid（H₂BDC）are used as raw materials.The Fe-BiOCl/Fe-MOF composites were synthesized by one-step solvothermal method by PVP as template agent.At 140°C,12 h,0.4 g and 0.667 mmol,Fe-BiOCl/Fe-MOF catalyst had the best degradation results,and the degradation rates of rhodamine B and tetracycline could reach 99.0%and 90.4%,respectively,at 90 min.（3）A 3D bowl-shaped Bi-DTC catalyst was prepared by solvothermal reaction using Bi³⁺as the metal source and 2,5-thiophenedicarboxylic acid（H₂TDC）as ligand at120°C and heating for 12 h.In addition,a certain amount of PVP was added to design a Bi-TDC material with a unique 3D red blood cell structure.Synergistic degradation of rhodamine B（RhB）solution by ultrasound-assisted photo.The experimental results show that the RhB degradation rate of PVP-assisted Bi-TDC material can reach 99.6%when ultrasound-assisted illumination is 90 min.（4）BiOBr/Bi-BDC and BiOBr/Bi-TDC were prepared by one-step solvothermal method using Bi³⁺as the metal source,terephthalic acid（H₂BDC）and 2,5-thiophenedicarboxylic acid（H₂TDC）as ligands,respectively.BiOBr/Bi-TDC and BiOCl/Bi-TDC were prepared with H₂TDC as ligand,cetyltrimethylammonium bromide（CTAB）and cetyltrimethylammonium chloride（CTAC）as Br^-and Cl^-source,respectively.By degrading rhodamine B（RhB）,BiOBr/Bi-TDC materials were found to have better catalytic activity.Finally,BiOBr/Bi-TDC composites containing different amounts of CTAB were studied.Under ultrasound-assisted illumination,the degradation rates of BiOBr/Bi-TDC-0.50 to RhB and TC could reach 99.8%and 96.1%in 30 min.