Amino-functionalization of graphene nanosheets by electrochemical exfoliation technique

作者：Gu, Si-Yong; Hsieh, Chien-Te^*; Yuan, Jun-Yao; Hsueh, Jen-Hao; Gandomi, Yasser Ashraf

来源：Diamond and Related Materials, 2018, 87: 99-106.

DOI：10.1016/j.diamond.2018.05.014

• Graphene sheets
• Electrochemical exfoliation
• Amino functionalization
• Amidation level

An electrochemical exfoliation route to functionalize graphene nanosheets (GNs) directly from a graphite electrode exposed to N-containing electrolyte is explored under constant-voltage (5-12 V) model. The selection of electrolytes (i.e., (NH4)(2)HPO4, (NH4)(2) SO4, and NH4NO3) used herein turns out to be a crucial factor in affecting the amidation level and amino group distribution on as-prepared GNs. The low-potential exfoliation assists an in-situ amino-functionalization reaction, imparting high N-surface coverage on GNs. The electro-chemical exfoliation in (NH4)(2) HPO4 is prone to the chemical doping of N element into sp(2) domain, whereas using (NH4)(2)SO4 and Na4NO3 electrolyte takes parallel pathway: chemical N doping and decoration of amino and amide-carbonyl groups at edges of GNs. The N/C ratio on the GN sample can reach as high as 8.4 at%, confirmed by X-ray photon spectroscopy. The tunable photoluminescence response of GN dots due to the amino functionalization is investigated, using a band-gap structure model. Accordingly, the efficient approach exhibits a controllable processing method for producing GN product because of its well-defined amidation extent and one-step process without any surface modification treatment.

• 出版日期2018-8
• 单位厦门理工学院