Preparation Of Metal Sulfides On Nitrogen Doping On Reduced Graphene Photocatalytic Materials And Application Study Of Photodegrading 2,4-dichlorophenol

Phenols and their derivatives are popular in our life.Taking 2,4-dichlorophenol?2,4-DCP?as an example,it is wildly used in the fields of fungicides,insecticides,pesticides.However,it is characteristic for its stability,carcinogen,strong odor.What's more,the remains of it have a potential impact on the ecosystem and lives,even jeopardizing people's health.Therefore,it is effective to deal with 2,4-DCP in the environment,which makes sense to environmental protection and sustainable development.There are a deal of methods to remove the 2,4-DCP in waste water including natural enzymes,photocatalysis,catalytic hydrodechlorination,activated carbon adsorption.Among them,photocatalytic technology that makes use of light energy to produce active species to photodegrade pollutants is characteristic for its green environmental,easy operation traits.Among many photocatalysts,CdS,as a n type semiconductor with relative wide band gap of 2.4 eV,has good photocatalytic performance.However,its applications are confined by high rate of recombination of electron-hole pairs,susceptible to photocorresion.Hence,we take a set of methods to modify it by constructing heterojunction photocatalyst,loading on support,modification of CQDs,and forming ternary metal sulfides.The details are listed below.The graphene oxide?GO?was prepared by modified Hummers method.Then N-rGO nanosheet was obtained by simple hydrothermal method of ammonia and hydrazine hydrate agents to reduce and dope.Then CdTe photocatalyst was fabricated by a hydrothermal method.While the CdTe/CdS/N-rGO composite photocatalyst was prepared in-suit by the solvothermal method.Their physico-chemical properties got characterized by high resolution transmission electron microscope?HRTEM?,X-ray diffraction?XRD?,mass spectrometry?MS?,ultraviolet-visible diffuse reflectance spectra?UV-vis DRS?,Raman,X-ray photoelectron spectroscopy?XPS?,photoelectric test and so on.The photocatalytic performances were measured by photodegradation of 2,4-DCP solution as simulating pollutants under visible light.When the molar ratio of CdTe to CdS was 1:3,it showed good photocatalytic performance.After loading the mass fraction of N-rGO to CdTe/CdS was 5%,the ternary composite showed full solar light response ability,which could photodegrade70%2,4-DCP under visible light.Taking cadmium chloride,indium chloride,L-cysteine as raw materials,we got different morphologies of CdIn₂S₄ by hydrothermal method of adjusting the temperature of synthesis,especially flower-sphere CdIn₂S₄ composed of irregular and looser nansheets at synthesis temperature of 160°C.A CdIn₂S₄/N-rGO composite photocatalyst with two-dimensional/two-dimensional sheet-like interfacial structure was formed by using N-rGO as a carrier to grow flaky CdIn₂S₄ by hydrothermal method.They were characterized by SEM,EDS,TEM,XRD,Raman,UV-vis DRS,XPS tests,photoelectric test and stuff.Their photocatalytic performances were measured by photodegrading 2,4-DCP.The result showed that binary composite photocatalyst could photodegrade 80%2,4-DCP when the mass fraction of N-rGO was 10%.With ascorbic acid,ethylene glycol and deionzed water as raw materials,we got CQDs by simple solvothermal method.Then CQDs modified flower-sphere CdIn₂S₄consisting of octahedron on N-rGO,forming muti-dimensional CQDs/CdIn₂S₄/N-rGO composite photocatalysts.Then the samples got characterized by SEM,EDS,Raman,XRD,BET,UV-vis DRS and their like,and their photocatalytic performances were evaluated by photodegrading 2,4-DCP.The results revealed that 69%2,4-DCP was photodegraded by CdIn₂S₄/N-rGO photocatalyst for 6 h under visible light when the mass fraction of N-rGO was 5%.After 0.5 mL CQDs modifying them further,the photodegradation rate could reach 80%.