Preparation Of Tin Disulfide Nanomaterials And Study On Their Photocatalytic Properties

Among many metal sulfides,tin disulfide(SnS₂)has the advantages of narrow band gap,good stability,non-toxic,cheap,and visible light response.Therefore it has a great development prospect in the field of photocatalysis.However,the low separation efficiency of photogenerated electrons and holes greatly restricts its photocatalytic activity.In recent years,the composite of nanometer SnS₂and two-dimensional graphene has been proved to be a material with high photocatalytic performance.The existence of graphene can effectively disperse SnS₂nanosheets to avoid agglomeration and transfer electrons simultaneously.In addition,construction of semiconductor heterojunctions enhance the visible light absorption of materials,effectively separate photogenic holes and electrons,and improve their photocatalytic activity.In this paper,we prepared pure SnS₂and binary materials SnS₂/rGO and SnS₂/SnO₂,and discussed their photocatalytic performance.On this basis,in order to obtain materials with higher catalytic activity and stability,we propose to introduce both graphene and SnO₂into SnS₂.The synergistic effect of the two can further accelerate the separation of electron and hole.The photocatalyst was characterized by XRD,SEM,TEM,XPS and UV-Vi S.The specific research contents are as follows:(1)Hydrothermal method was used to prepare SnS₂materials.Firstly,the influences of thiourea,KSCN and thioacetamide on the morphology and properties of SnS₂were investigated.From the degradation efficiency of Rhodamine B(Rh B),SnS₂prepared with thiourea as the sulfur source has good photocatalysis.Then the effects of type and initial concentration of dyes,and the amount of catalyst on SnS₂photocatalytic reaction were explored.The experimental results showed the optimal reaction conditions:MO had the better photocatalytic degradation,catalyst dosage was 40mg,concentration of MO was 10mg/L.(2)Binary photocatalytic materials SnS₂/rGO and SnS₂/SnO₂were prepared by hydrothermal method.In the SnS₂/rGO study,it was found that the addition of graphene could provide a large growth surface for nano-SnS₂,and its photocatalytic efficiency was slightly improved.In the analysis of the SnS₂/SnO₂heterojunction,different mole ratios of tin source and sulfur source were used to compound materials.when the ratio was 1:1.5,SnS₂and SnO₂could form more heterojunction structures to accelerate electron transport,and greatly improve photocatalytic activity.(3)Ternary SnS₂/SnO₂/rGO materials were prepared by one-step hydrothermal method.The results of SEM and TEM showed that SnO₂was grown in situ on SnS₂nanocrystals and dispersed on graphene.In the photocatalytic experiments,the degradation rate of MO was 94%,which was far higher than that of SnS₂,SnS₂/rGO and SnS₂/SnO₂materials.SnS₂/SnO₂/rGO nanocompound has a certain cycling stability,indicating that it could be used as a high efficiency catalyst.