一步热聚合法制备Cu_(2)O/CuO-g-C_(3)N_(4)吸附剂及其对甲基橙吸附的性能

Preparation of Cu_(2)O/CuO-g-C_(3)N_(4)Adsorbent by One-step Thermal Polymerization and Adsorption Properties for Methyl Orange

用一步热聚合法制备了一种铜改性的石墨氮化碳吸附剂,并研究了其对甲基橙的吸附性能。以氧化亚铜、双氰胺为前驱体,以氯化胺作为气体模板,在高温下引发聚合获得了铜改性的石墨氮化碳吸附剂(Cu_(2)O/CuO-g-C_(3)N_(4))。采用扫描电子显微镜(SEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)及全自动比表面及孔隙度分析(BET)等对所制备吸附剂的组成和结构进行了表征,结果表明,该吸附剂由Cu、C、N和O共4种元素组成具有介孔结构的层状材料。引入铜氧化物以后,有效地扩展了g-C_(3)N_(4)的π共轭体系,有利于通过π-π作用吸附带有苯环结构的染料;Cu_(2)O/CuO-g-C_(3)N_(4)吸附剂具有多种孔径的介孔结构增大了其比表面积,为染料的吸附提供了足够的活性位点。通过优化吸附剂的制备条件、投加量、染料浓度、吸附时间、搅拌转速和pH等参数后,获得在最优条件下对甲基橙溶液的吸附率仅需25 min即可达到96.11%。进一步地,在常温常压下,通过动力学分析,该吸附过程更倾向于准一阶动力学模型;通过吸附等温实验验证,该吸附等温线属于Langmuir吸附等温线,在整个吸附实验中,最大平衡吸附容量为241.25 mg/g。

In this paper,Cu_(2)O/CuO graphite carbon nitride adsorbent is prepared by one-step thermal polymerization with cuprous oxide and dicyandiamide as precursors.The introduction of copper oxide expands theπconjugation system of g-C_(3)N_(4)effectively,which is conducive to the adsorption of dyes with benzene ring structure throughπ-πinteraction;Cu_(2)O/CuO-g-C_(3)N_(4)adsorbent has mesoporous structures with various pore sizes,which increases its specific surface area and provides sufficient active sites for dye adsorption.The adsorption influencing factors of methyl orange,such as the preparation conditions of adsorbent,dosage,dye concentration,adsorption time,stirring speed,pH,etc.,are studied.The maximal absorption ratio is 96.11%under the optimal conditions.The kinetic analysis shows that the adsorption process is a quasi first-order kinetic model.According to the adsorption isothermal experiment,the adsorption isotherm belongs to Langmuir adsorption isotherm.In the whole adsorption experiment,the maximum equilibrium adsorption amount is 241.25 mg/g.