Graphene oxide reduced and modified by soft nanoparticles and its catalysis of the Knoevenagel condensation
Graphene oxide reduced and modified by soft nanoparticles and its catalysis of the Knoevenagel condensation
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DOI：
10.1039/c2jm15311d
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发表时间：
2012-02
影响因子：
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通讯作者：
Tao Wu;Xingrui Wang;Haixia Qiu;Jian-ping Gao;Wei Wang;Yu Liu
中科院分区：
文献类型：
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作者：
Tao Wu;Xingrui Wang;Haixia Qiu;Jian-ping Gao;Wei Wang;Yu Liu
以氨基封端的聚（酰胺亚胺）（PAMAM）树枝状大分子作为还原剂和稳定剂，制备了一种还原氧化石墨烯（RGO）的方法。考察了PAMAM的生成量、PAMAM/GO的比例、pH值、还原温度等因素对氧化石墨烯（GO）还原的影响。采用紫外-可见吸收光谱、拉曼光谱、X射线衍射光谱、热重分析、X射线光电子能谱和透射电子显微镜对还原后的氧化石墨烯进行了表征。PAMAM树枝状聚合物在短时间内有效地还原了GO，并且它们吸附到RGO纳米片上使得RGO稳定地分散在水和有机溶剂（如N，N-二甲基甲酰胺和二甲基亚砜）中。PAMAM修饰的RGO可以催化Knoevenagel缩合反应，产率高达99%，是一种活性很高的有机催化剂。
An approach to prepare reduced graphene oxide (RGO) was developed using soft nanoparticles, amino-terminated poly(amidoanime) (PAMAM) dendrimers, as both a reducing agent and a stabilizing agent. Several factors that affect the reduction of graphene oxide (GO), including the PAMAM generation, the ratio of PAMAM/GO, the pH, and the reduction temperature were investigated. The reduced graphene oxide was characterized with UV-visible absorption spectroscopy, Raman spectroscopy, X-ray diffraction spectroscopy, thermo-gravimetric analysis, X-ray photoelectron spectroscopy and transmission electron microscopy. The PAMAM dendrimers efficiently reduced GO in a short time, and their adsorption onto the RGO nanosheets allows RGO to stably disperse in water and organic solvents, such as N,N-dimethyl formamide and dimethyl sulfoxide. PAMAM modified RGO can catalyze the Knoevenagel condensation with yields up to 99%, and thus is a very active organocatalyst.