Study On Carbon Materials Derived From Co/ni-based MOFs In Catalytic Degradation Of Pollutants

Macromolecular organic pollutants have a wide variety and are difficult to remove by traditional treatment methods.They are often easy to be detected in the water environment and pose a serious threat to the environment.For this reason,scientists have carried out in-depth research on these refractory pollutants,and the emergence of advanced oxidation method has solved the urgent problem of similar pollution.Sulfate radical based advanced oxidation processes（SR-AOPs）has higher potential and half-life compared with hydroxyl radical and more better to contact with pollutants.Metal organic frameworks（MOFs）are formed by self-assembly.Their structures have many advantages,such as periodicity,high porosity,specific surface area and strong stability,and can be widely used in the catalytic field.Although transition metal based MOFs materials have excellent catalytic performance,the secondary spillage of metal ions will lead to irreversible secondary pollution of the water environment.Therefore,improvements should be made on the basis of MOFs materials to reduce the environmental threat caused by secondary pollution.In recent years,nanostructured carbon materials have begun to be widely used in catalytic degradation of pollutants.Carbon coated nanoparticle catalysts obtained by pyrolysis of MOFs as precursors have the characteristics of porous and multi active sites.At the same time,as the carbon source,the ligands in MOF can be uniformly wrapped around metal particles,which can greatly reduce the secondary pollution caused by metal ion spillage.This paper discusses the preparation of carbon derived catalysts based on the pyrolysis of MOFs,and studies the performance of pollutants degradation by activating peroxymonosulfate（PMS）.（1）New cobalt MOFCUST-591（[Co₂（NTB）（DPE）0.5（H₂O）₂]}·4H₂O·DMA）was synthesized by solvothermal method.The carbon material Co/Co O/C was obtained by calcining the crystal in an inert gas environment at 700°C.The catalytic performance was verified by the degradation of different antibiotics.The results showed that the catalyst had good catalytic performance for tetracycline（TC）and oxytetracycline（OTC）.At the same time,the effects of p H,temperature and other factors on the results were studied,and the main free radicals involved in the process and the possible mechanism were studied through the free radical quenching experiment.（2）CUST-593（[Co（NTB）（BIPY）（H₂O）]·0.5H₂O·0.1DMA）,which was synthesized by solvothermal method,is used to study the degradation performance of dyes.The selectivity and high efficiency of the catalytic performance of dyes are explored through factors such as different catalysts,PMS dosage,different temperature,p H,dye types and concentrations.The experimental results show that the catalyst has a good degradation ability for the degradation of methyl orange（MO）and rhodamine B（Rh B）.The removal rate of methyl orange（MO）and rhodamine B（Rh B）can reach 95.7%and 90%respectively in 20 min and40 min.Simultaneously,the free radical quenching experiment proved that SO ₄^·-was the main active free radical,and·OH also participated in the degradation process to a small extent.（3）Cobalt based precursor CUST-594 was synthesized by solvothermal method with triimidazole and 2-bromo-terephthalic acid as ligands,and porous carbon was synthesized by pyrolysis at 600°C under shielding gas.The degradation of antibiotics was studied.Comprehensive experimental results showed that the material had good catalytic degradation ability for tetracycline（TC）and chloramphenicol（CAP）.The influence of different conditions on the degradation ability was also explored.Finally,the mechanism study confirmed that there are free radicals and non-free radicals in the reaction.