The Study Of Rhodamine B Degradation By Photocatalytic Under Different Systems

In the21st century, we are facing two major problems, the energy andenvironmental issues. Photochemical catalysis have great application prospect to solvethe energy shortage and environmental pollution. However, the traditionalphotochemical materials, such as TiO2, ZnS and ZnO are wide band gap photocatalysts,and can only absorb ultraviolet light. Ultraviolet light accounts for only4%of naturallight energy, but the visible light accounts for46%of natural light energy. So, the firstkey problem needed to solve is developing and researching photochemical catalysisprocess to visible light response. Sulphide photocatalysis technology and light catalyticFenton reagent have a certain similarity, because their reaction will generate hydroxylfree radical (HO·). Metal sulfide is considered to be excellent visible light catalyst andits narrow band gap width makes the metal sulfide have potential application prospect inthe field of visible light catalytic oxidation. Fenton reagent has the very high oxidationability, and is extensively studied at home and abroad in industrial wastewatertreatment.Graphene (GO) is a material which has a two-dimensional layered structure, andthere are a large number of polar functional groups on every layer, and it can react witha variety of substances, embedding them into grapheme. By in-situ growth of grapheneintegration with the sulfide to form a composite material，it can be a good solution to theproblem of metal sulfide aggregates, and through this composite effect, it helps makethe composite material to get better photoelectrochemical function than a single material.First this paper uses the method of the secondary oxidation oxidating natural graphite,successfully prepared graphene oxide processing. By this method, loading the metal sulfide CdS, ZnS particles to the grapheme, making ZnS/GO, CdS/GO andZnS+CdS/GO compounds. Using graphene’s unique physical characteristics studies theeffect of the catalytic performance of metal sulfides, and explores the catalystcharacteristics of the rhodamine B degradation. The conclusion is that photocatalyticactivity of Rhodamine B degradation of metal sulphides and graphene composite wassignificantly better than a single sulfide photocatalytic materials. The reasons of sulfideand graphene composites have better photocatalytic activity are: graphene has superiorelectron transfer ability and higher specific surface area, graphene can make carrier lightquickly migrate to the surface of the catalyst, and participate in the light reaction. Butpure ZnS does not have good photocatalytic performance. Between different metalsulfide materials, CdS/GO has the best catalytic activity.The current study mainly investigates the influences of the light and nonlightcondition, different kinds of quinone containing organic matter, ferric iron, radicalquencher and hydrogen peroxide on the characteristics of Fenton degradation ofRhodamine B. The results showes the simulated solar irradiated organic matterscontaining quinone structure can enhance the Fenton reaction process and consequentlystrengthen the degree of Rhodamine B degradation. The acceleration of Fenton reactionprocess is attributed to the recycle between the two species of iron, Fe() and Fe(),which is driven by the interaction process between the organic matters containingquinone structure and simulated solar light irradiation.