Study On Synthesis And Properties Of Hollow Double-shelled CdS@ZnS Nanocomposites

Core-shell structure materials have been extensively studied in photocatalytic technology.The properties of the core-shell structure materials can be modified by changing either the constituting materials or the core to shell ratio.The core-shell nano composite materials,which is based on CdS,have been widely concerned as a new type of materials in recent years.However,CdS is prone to produce "light corrosion",which not only causes water pollution,but also reduces the photocatalytic activity of the materials.For the above questions,CdS@ZnS nanocomposites with hollow and double-shelled structure will be prepared in this study.The monodisperse polystyrene microspheres were synthesised by using a conventional chemical approach which called emulsion polymerization.The core-shell composite material PS@CdS was synthesized with PS as a template,Cd(Ac)2 and thioacetamide as precursors.The polyvinyl pyrrolidone was introduced as stabilizer and dispersant by different methods.Then the PS@CdS@ZnS double-shelled nano composites were obtained.The different experimental methods,different precursors and the influence of different dosage of PVP on experiment were explored.Finally,the hollow CdS nano materials and hollow CdS@ZnS core-shell nano composite materials were synthesized by being dissolved in toluenetoluene or high-temperature calcination.The size,microstructure and composition of the nanoparticles and light absorbing properties were investigated by SEM,TEM,EDS,XRD,FT-IR and UV-vis.The results showed that the materials possessed hollow and double-shelled structure,favourable monodispersion and high mechanical strength.Its thickness of inner shell range is from 80 to 100 nm,and thickness of outershell is about 40 nm.Its good visible-light degradation ability was demonstrated by degrading for dying wastewater under visible-light irridation.After 160 minutes under visible light irradiation,the degradation rate of 300 mL,10 mg·L-1of RhB solution was 99.7%,which was degraded by 0.2 g·L-1 of hollow double-shelled CdS@ZnS nanocomposites.Meanwhile,the catalyst can be reused and its degradation rate was stable at 98% around.The experiments showed that the materials can reduce the water pollution caused by Cd2+,which revealed a great potential in the treatment of dying wastewater.