过硫酸铵在氧化石墨烯表面的吸附机理研究

Adsorption Mechanism of Ammonium Persulfate on Graphene Oxide Surface

过硫酸胺(APS)可通过氢键与氧化石墨烯(GO)表面的氧化基团产生相互作用,为聚苯胺(PANI)的聚合反应提供活性位点,并可引发PANI在GO表面的规则堆积,从而改善聚苯胺/石墨烯复合材料的电化学性能。本文使用石英晶体微天平(QCM)研究了APS在GO层片表面吸附机理。实验结果表明,吸附过程在大部分时间符合一级吸附动力学,298K的理论吸附量为164.18μg·mg^-1,且GO对APS的吸附由物理扩散控制。通过吸附动力学过程分析可推测出APS在GO层片表面的吸附过程为两段式吸附,即吸附率先发生在GO氧化基团处,该吸附过程达到饱和后仍可继续发生APS在GO表面六元环处的吸附。

Ammonium persulfate(APS)can interact withoxygen groups in graphene oxide(GO)through hydrogen bonding,which provided active sites for polymerization of polyaniline(PANI)and initiated regular stacking of PANI on GO surface.This canimprovethe electrochemical performance of polyaniline/graphene composites.In this work,the adsorption mechanism of APS on GO sheet has studied by quartz crystal microbalance(QCM).The results show that the adsorption process can be described byfirst-order adsorption kinetic modelfor most of the time,and the theoretical saturated adsorption capacity of APS on GO sheet is 164.18μg mg^-1 under 298 K.Theprocess ofGO adsorption for APS is controlled by physical diffusion.It can be concluded form the analysis of adsorption kinetics process that the adsorption of APS on GO surface belong tothe process of two-stage adsorption.APS adsorbedon the oxygen groupsofGO surfacefirstly,and then adsorbedonhexatomic rings of GO surface continually when former adsorption process reaches its saturation.