Research On Photocatalytic Degradation Of Rh B And Xylene By CQDs/Clinoptilolite Composites

At present,water pollution caused by large amount of printing and dyeing wastewater discharge and air pollution caused by VOCs are seriously troubling people's production life,therefore,for the treatment of printing and dyeing wastewater and VOCs pollution,photocatalytic technology is considered as an efficient method.However,photocatalysts are not widely used in the treatment of wastewater and waste gases due to their high cost and complicated preparation.Therefore,Therefore,carbon quantum dots loaded with clinoptilolite as a carrier were designed and CQDs/clinoptilolite composites were prepared to provide a simple to prepare,inexpensive and non-toxic photocatalytic material for photocatalysis technology.The main studies in this paper are as follows.(1)Different ratios of CQDs/clinoptilolite composites were chosen to be prepared by hydrothermal method,and the influence of the relative content of carbon quantum dots on the morphology,structure and surface functional groups of clinoptilolite was investigated by using SEM,TEM,XRD and XPS characterisation methods to analyse the microscopic morphology,crystal structure and elemental composition of the composites.The results showed that the hydrothermal method was successfully used to uniformly load the clinoptilolite with carbon quantum dots,and the loading of carbon quantum dots increased with the increase of carbon source ratio.(2)Rh B was selected as the target for the photocatalytic degradation of CQDs/clinoptilolite composites,and the degradation mechanism of Rh B was investigated.The results showed that the loading of carbon quantum dots on the clinoptilolite zeolite could effectively enhance the photocatalytic performance of the material.During the synthesis of carbon quantum dots,the composite achieved the best photocatalytic performance with 100% degradation of Rh B at a carbon source dosage of 2.475 g.The radical capture experiments showed that superoxide radicals and hydroxyl radicals played a major role in the degradation of Rh B.Combined with the characterisation of the composites,the loading of carbon quantum dots effectively improved the efficiency of the production of these two active substances.(3)The photocatalytic degradation study of CQDs/clinoptilolite composites was carried out to investigate the degradation mechanism of xylene gas.The results showed that the loading of carbon quantum dots on the clinoptilolite zeolite could enhance the photocatalytic performance of the material and achieve effective degradation for the more difficult to degrade xylene gas pollutant.The composite reached its optimum performance when the glucose dosage was 2.475 g,with a degradation rate of 97.4% for xylene.Free radical capture experiments showed that hydroxyl radicals and superoxide radicals are also active in the photocatalytic degradation of xylene.In this thesis,the photocatalytic degradation of Rh B and xylene was investigated,and it was found that the CQDs/clinoptilolite composites could achieve good degradation in both liquid and gas phases as the catalytic reaction system environment,with good adaptability to the reaction conditions.In addition,the results provide data support for the degradation of dye wastewater and VOCs by CQDs/clinoptilolite composites,which is of great significance for the research of photocatalytic materials with clinoptilolite as the main material.