纳米银/二维石墨相氮化碳/还原氧化石墨烯复合材料的制备及其光催化降解抗生素

Preparation of Ag/Two-Dimensional Graphitic Carbon Nitride/Reduced Graphene Oxide Composite and Its Photocatalytic Degradation of Antibiotics

为优化石墨相氮化碳(g-C 3 N 4)光催化剂的结构,改善其对污染物的降解性能,本文以三聚氰胺为前驱体,通过高温煅烧和热氧化剥离制备了二维石墨相氮化碳(2D-C 3 N 4),并用光还原法一步合成纳米银/二维石墨相氮化碳/还原氧化石墨烯(Ag/2D-C 3 N 4/rGO)复合光催化剂。通过X射线粉末衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、紫外-可见漫反射光谱(UV-Vis DRS)、光致发光光谱(PL)、X射线光电子能谱(XPS)、氮气吸附脱附等温曲线(BET)等对材料进行表征。以头孢曲松钠为目标污染物,探究pH值、催化剂用量、头孢曲松钠初始浓度等因素对催化剂的吸附、降解性能的影响,并探究降解反应机理。当pH=6.0,催化剂用量为0.3 g/L,头孢曲松钠初始浓度为10.0 mg/L时,复合材料对头孢曲松钠的降解率可达到89.1%。催化剂的稳定性较强,具有实际应用价值,可用于处理含头孢类抗生素的废水。

In order to optimize the structure of graphitic carbon nitride(g-C 3 N 4)photocatalyst and improve its degradation performance to pollutants,two-dimensional graphitic carbon nitride(2D-C 3 N 4)was prepared by high temperature calcination and thermal oxidation stripping with melamine as the precursor.Ag/2D-C 3 N 4/rGO(reduced graphene oxide)composite photocatalyst was synthesized by photoreduction method.The material obtained was characterized by X-ray powder diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),ultraviolet-visible diffuse reflectance spectroscopy(UV-Vis DRS),photoluminescence spectroscopy(PL),X-ray photoelectron spectroscopy(XPS)and nitrogen adsorption desorption isotherm curve(BET).Taking ceftriaxone sodium as the target pollutant,the effects of pH,catalyst dosage and initial concentration of ceftriaxone sodium on the adsorption and degradation properties of the catalyst were investigated,and the degradation reaction mechanism was explored.When pH=6.0,the amount of catalyst is 0.3 g/L,and the initial concentration of ceftriaxone sodium is 10 mg/L,the degradation rate of ceftriaxone sodium can reach 89.1%.The catalyst has strong stability and can be used for treating wastewater containing cephalosporin antibiotics.