Synthesis Of Micro/nano Structural Zno、Zns Complex Materials And Their Photocatalytic Properties

In recent years, due to non-toxic, low cost and possessing unique physical and chemicalproperties, ZnO, ZnS and their complex micro-nano materials have attracted intensiveattentions around the world. Based on its high efficiency, no polution, photochemical stability,the application of ZnO, ZnS complex micro-nano structures on photocatalytic degradation oforganic contaminant is a promising technology for wastewater treatment. However, somedefects of this kind of photocatalyst, such as low quantum efficiency, low degradationefficiency, easily compounded of electron-hole and so on, limit its further applications. In thisarticle, ZnO、ZnS and its complex micro-nano structural materials have been synthesized inthe hydrothermal/sovlvothermal method, and the material morphologies, optical property andphotocatalytic degradation were studied in details. The main contents as follows:⑴ZnO microspheres and ZnS nanospheres were successfully fabricated via a mildsolvothermal/hydrothermal method. The influences of hydrothermal temperature, reactiontime and surfactant addition on the morphology and size of products have been investigated.We found that the diethylene glycol as solvent played an important role on the formation ofthe ZnO microspheres, and surfactant sodium dodecyl sulfate and cetrimonium bromide alsoplayed a key role for the formation of nano ZnS spheres. In addition, the PL properties of ZnOmicrospheres and ZnS nanospheres have been investigated, respectively.⑵Spherical ZnO/ZnS core/shell composites have been successfully synthesized via afacile conversion process from ZnO microspheres precursors. The different sulfur source andZn2+/S2-on the influence of the shell thickness, photoluminescence and photocatalyticdegradation efficiency had been discussed. The results showed best photoluminescence whenZn2+/S2-= 2/1 and high photocatalytic degradation towards Methyl Orange and RhodaminBmodel wastewater when Zn2+/S2-= 1. This strategy may provide more opportunities for thepreparation of core/shell structured micro-nano materials and application in wastewatertreatment.⑶In order to improve the photoluminescence and photocatalytic degradation efficiency,Spherical ZnO:Ag and ZnS:Ag composites have been successfully synthesized via a mildsurface deposition process. ZnO:Ag microspheres of 5% Ag addition showed goodphotoluminescence and photocatalytic degradation towards Methyl Orange and RhodaminBmodel wastewater. And ZnS:Ag nanospheres of 2% Ag addition showed better photocatalyticdegradation towards the same model wastewater. ZnS:Ag photocatalyst have been used manycircles, the results presented that the novel pgotocatalyst was stable and rarely change inphotocatalytic degradation efficiency.