GC 3 N 4 And Manganese Oxide Composites Are Used In The Research Of Photothermal Synergistic Catalysis

Today,the full speed development of science and technology is unprecedented.We find that the whole earth environment mankind depend on for existence can't bear the heavy load more and more.Among the varied environment problems,the water resource problem is undoubtedly the most severe environment problem nowadays and even in the future that the mankind face.Therefore,it is important that photocatalytic oxidation be developed.In these water treatment technologies,advanced oxidation technologies include H2O2 oxidation,photocatalytic oxidation and so on.Photo-thermal synergistic oxidation is a kind of new type of wastewater treatment technology.It has the advantages of high processing efficiency,easy control of operating conditions,non-selective degradation of organic pollutants,no secondary pollution,etc.,and may be wide range of applications.In this paper,Mn3O4 was chosen as the Fenton catalyst and g-C3N4 as the photocatalyst.Mn3O4 as a highly efficient heterogeneous Fenton catalyst can catalyze the reaction under neutral conditions and overcome the shortcomings of the traditional iron Fenton catalyst:(1)the reaction should be carried out under acidic conditions of pH <3 in order to achieve good removal effect;(2)homogeneous iron catalyst will produce a large number of precipitates after the reaction,not only secondary to water pollution,and is not conducive to the recovery of the catalyst and re-use.Mn3O4 with different morphologies was prepared by adjusting the type of alcohol added during the hydrothermal process.The effects of H2O2 addition and different reaction substrates were studied by single factor experiment.In order to further improve the efficiency of pollutant removal,Mn3O4 / g-C3N4 composites were synthesized and used in the study of Photo-thermal synergistic catalysis.g-C3N4 is a typical metal-free polymer which has a suitable bandgap width and visible light absorption properties.It is more conducive to practical application for its excellent visible light adsorption capacity and the characteristics of large-scale preparation.g-C3N4 produces a certain amount of H2O2 through adouble electrons process under visible light irradiation.At the same time,Mn3O4 was found to be a heterogeneous Fenton-like catalyst with excellent performance.The reaction conditions were easy to be achieved and the catalysts could be separated easily.The photocatalytic material g-C3N4 was combined with the thermal catalytic material Mn3O4,and the photocatalytic photocatalysis and Fenton thermal catalysis were carried out under the condition of visible light irradiation,and the photocatalytic catalysis was realized by using the H2O2 produced by the system itself.In this paper,the morphological structure,the interaction between the materials and the charge transfer were studied by FESEM,XRD,XPS and PL.In order to investigate the photo-thermal synergisticperformance of Mn3O4/g-C3N4 composites,we applied it to liquid organic pollutant removal,volatile organic compounds(VOC)degradation,selective oxidation of benzyl alcohol and other catalytic processes.The composite exhibits excellent catalytic performancethat achieved high catalytic activity while avoiding additional H2O2,reducing energy consumption.The excellent catalytic performance of Mn3O4/g-C3N4 composites is possible for its practical application.