rGO/MoS_(2)-CN的制备及可见光催化降解磺胺类抗生素的性能研究

Fabrication rGO/MoS_(2)-CN for photocatalytic degradation of sulfonamides under visible light

以三聚氰胺为前驱体制备了石墨型氮化碳(MCN)材料,并通过超声辅助浸渍法,将MCN与还原氧化石墨烯(rGO)和二硫化钼(MoS_(2))纳米片复合,成功制备了rGO/MoS_(2)-CN三元复合材料.采用SEM、XRD、UV-vis和BET等多种手段对材料进行系统表征分析.以磺胺嘧啶(SDZ)、磺胺甲恶唑(SMX)、磺胺异恶唑(SSX)和磺胺二甲嘧啶(SMZ)四种磺胺类抗生素为目标物,考察了rGO/MoS_(2)-CN在可见光条件下的催化活性.结果表明rGO/MoS_(2)-CN与MCN相比,对SDZ、SSX、SMX和SMZ的降解效率大幅提升,可见光照60 min,降解百分比分别提高51.22%、52.62%、38.47%和45.05%.rGO/MoS_(2)-CN比表面积的增加有利于电子的传输与分离,对可见光吸收利用能力也显著增强.此外,系统研究了催化剂用量、抗生素初始浓度、pH值变化、微塑料颗粒等对目标抗生素降解率的影响.通过活性物种捕获实验,明确了参与抗生素降解的主要活性物种,阐述了降解机理.rGO/MoS_(2)-CN材料的制备和应用有助于减轻水体抗生素残留给环境造成的危害.

Graphitic carbon nitride(MCN)was prepared first using melamine,then a novel rGO/MoS_(2)-CN nanocomposite photocatalyst was synthesized via impregnation method with the assistance of ultrasound.SEM,XRD,UV-vis and BET were used to investigate the structure and properties of the samples.The photocatalytic activities of rGO/MoS_(2)-CN were evaluated by decomposing sulfadiazine(SDZ),sulfamethoxazole(SMX),sulfisoxazole(SSX)and sulfamerazine(SMZ)under visible light irradiation.Compared to MCN,rGO/MoS_(2)-CN composites showed the improved photoactivity with SDZ,SSX,SMX and SMZ degradation percentage of 51.22%,52.62%,38.47%and 45.05%higher after 60 min visible light irradiation.The enhancement activity can be assigned to the larger BET specific surface areas,which can promote light trapping and charge separation.Besides,the effects of catalyst dosage,initial concentration of antibiotics,solution pH and the presence of microplastics on the photodegradation process were discussed.The degradation mechanism of four sulfonamides was proposed based on the results of trapping experiments.This study provides an insight into the rGO/MoS_(2)-CN nanocomposite for antibiotics removal.