基于不同前驱体的碳点对重金属吸附性能的比较研究

Carbon dots based on the various precursors for the adsorptive performances of heavy metals:A comparative study

以葡萄糖、蔗糖和果糖为前驱体,利用水热反应分别制备了葡萄糖碳点、蔗糖碳点和果糖碳点,利用TEM、IR、XPS等手段表征其形貌和官能团。实验发现制备的三种碳点的微观形态均呈球状,其粒径均小于5nm,且均含有羟基、羧基等官能团;在竞争和非竞争条件下测定了三种碳点对重金属离子的吸附能力。结果表明,制备的三种碳点能够选择性地结合Cu^(2+)和Pb^(2+)离子;其中蔗糖碳点对Cu^(2+)和Pb^(2+)离子的吸附容量最好,分别为1.02和1.48 mmol·g^(-1)。蔗糖碳点对Cu^(2+)和Pb^(2+)离子吸附的最佳pH值为6;蔗糖碳点对Cu^(2+)和Pb^(2+)离子吸附能力随溶液离子强度的增大而逐渐降低。

Carbon dots based on the glucose,sucrose and fructose as the precursors were prepared by hydrothermal reaction.Their morphology and functional groups of the three carbon dots were characterized by TEM,IR and XPS spectra.The spherical nanoparticles of the three carbon dots with size below 5 nm were observed,and the three carbon dots contained hydroxyl,carboxyl and other functional groups.The adsorption capacities of the three carbon dots for heavy metal ions were measured under competitive and noncompetitive conditions.The results showed that the three carbon dots could selectively bind the Cu^(2+)and Pb^(2+)ions.The carbon dots based on sucrose exhibited a better adsorption capacity for the Cu^(2+) and Pb^(2+) ions,which were found to be 1.02 and 1.48 mmol·g^(-1),respectively.The optimum pH of the carbon dots based on sucrose for the adsorption of the Cu^(2+)and Pb^(2+)ions was 6.The adsorption capacities of Cu^(2+)and Pb^(2+)ions by the carbon dots based on sucrose decreased gradually with the increase of ionic strength in solution.