银掺杂对石墨烯/CdTe量子点复合物荧光发射性能的影响

Effect of Silver Doped on Fluorescence Emission Properties of Graphene/CdTe Quantum Dot Composites

在氮气保护下,水相中以巯基丙酸与巯基石墨烯为稳定剂,制备得到银掺杂石墨烯/CdTe量子点复合材料.荧光发射光谱表明:掺杂银离子后,石墨烯/CdTe量子点复合物的最大荧光波长发生明显红移,且随加热时间的增加而增大,直至平衡,该平衡过程符合二级反应动力学吸附模型的规律;当银离子初始质量浓度为18.75,37.50,56.25 mg/mL时,利用二级吸附动力学公式可推算最大荧光发射波长分别684.93,735.29,746.27 nm.可见银离子初始质量浓度越大,达到平衡后最大荧光发射波长越大,最大荧光发射强度依次减小.为得到较大的荧光发射波长及荧光发射强度适中的量子点,最优银离子添加量为37.50 mg/mL.

Silver doped graphene/CdTe quantum dot composites were prepared by using mercaptopropionic acid and mercaptographene as stabilizers in aqueous phase under the protection of nitrogen.The fluorescence emission spectra show that after doping silver ions,the maximum fluorescence wavelength of the graphene/CdTe quantum dot composites significantly red-shifts,and increases with the increasing of heating time until equilibrium,which conforms to the law of the second-order reaction kinetic adsorption model.The maximum fluorescence emission wavelengths can be calculated as 684.93,735.29,746.27 nm by using the second-order kinetic adsorption model when the initial mass concentrations of silver ions are 18.75,37.50,56.25 mg/mL.Therefore,the greater the initial mass concentration of silver ions,the greater the maximum fluorescence emission wavelength after reaching equilibrium,but the maximum fluorescence emission intensity decreases in turn.In order to obtain quantum dots with large fluorescence emission wavelength and moderate fluorescence emission intensity,the optimal amount of silver ions is 37.5 mg/mL.