Electrolytic graphene oxide and its electrochemical properties
Electrolytic graphene oxide and its electrochemical properties
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DOI：
10.1016/j.jelechem.2013.06.012
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发表时间：
2013-09-01
影响因子：
4.5
通讯作者：
Funatsu, Asami
中科院分区：
文献类型：
--
作者：
Matsumoto, Yasumichi;Tateishi, Hikaru;Funatsu, Asami
低成本的氧化石墨烯（GO）和相关材料被认为是超级材料，因为它们对于许多受氧化程度和掺杂剂（杂质）影响很大的应用具有独特和优异的性能。传统的Hummers法制备的GO氧化程度和杂质含量难以控制。在这里，我们展示了一种简单的一步法，通过在高压下在纯水中电解在石墨基底[即玻璃碳（GC）、高取向热解石墨基底平面表面（HOPG-b）和高取向热解石墨边缘表面（HOPG-e）]上制备纯GO;所得GO称为电解GO（eGO）。通过调整施加电压和电解时间，可以容易地控制eGO中的氧化程度，并且通过在电解期间在基板上使用对尖端电极，可以获得小尺寸的eGO。光电化学还原的eGO（r-eGO）具有大的双电层充电电容和高的氧还原反应（ORR）电催化活性，并作为n型半导体电极。在HOPG-b上形成的r-eGO具有比在HOPG-e上更大的电容和更高的ORR活性。通过X射线光电子能谱和拉曼光谱证明，r-eGO的优异性能是由于碳缺陷和/或通过在基面处形成的环氧基团的还原产生的OH基团。金属氧化物或氢氧化物在r-eGO上的光电化学沉积增加了材料的电容和催化活性。(C)2013年由Elsevier B. V.出版
Low-cost graphene oxide (GO) and related materials are considered supermaterials because of their unique and excellent properties for many applications that are greatly affected by oxidation degree and dopants (impurities). Conventional GO prepared by the multistep Hummers' method is unable to control degree of the oxidation and impurities. Here, we demonstrate a facile one-step method for preparing pure GO on graphite substrates [i.e. glassy carbon (GC), highly oriented pyrolytic graphite-basal plane surface (HOPG-b), and highly oriented pyrolytic graphite-edge surface (HOPG-e)] by electrolysis in pure water under high voltage; the resultant GO is called electrolytic GO (eGO). The degree of oxidation in eGO can be easily controlled by adjusting the applied voltage and the electrolysis time, and small-sized eGO can be obtained by using a counter tip electrode on the substrate during the electrolysis. Photoelectrochemically reduced eGO (r-eGO) had a large double-layer charging capacitance and high electrocatalytic activity for the oxygen reduction reaction (ORR), and acted as an n-type semiconductor electrode. The r-eGO formed on HOPG-b had larger capacitance and higher activity for ORR than that on HOPG-e. The excellent properties of r-eGO were due to carbon defects and/or OH groups produced by the reduction of epoxide groups formed at the basal plane, as evidenced by X-ray photoelectron spectroscopy and Raman spectroscopy. The photoelectrochemical deposition of metal oxides or hydroxides on r-eGO increased the capacitance and catalytic activity of the material. (C) 2013 Published by Elsevier B.V.