电位调控制备还原氧化石墨烯的电催化性能研究

本文通过控制电位还原氧化石墨烯,可控制备不同含氧官能团的石墨烯纳米材料。以多巴胺、Fe(CN)_6]~(3-)、NADH为电活性探针,研究了石墨烯表面含氧官能团、缺陷、表面荷电性质以及导电性等对石墨烯电催化性能的影响。研究发现,低还原程度的氧化石墨烯表面含有大量缺陷和丰富的官能团,能够促进多巴胺自催化反应,也有利于K_3Fe(CN)_6]在电极表面的电子转移;随着氧化石墨烯还原程度提高,其导电性逐渐得到改善,且其表面官能团和缺陷位点数量逐渐减少,对NAD~+的吸附变弱,因而能促进NADH发生电催化氧化。

Study on the Electrocatalytic Behavior of Electrochemically Reduced Graphene Oxide

A potentiostatic approach to the preparation of electrochemically reduced graphene oxide(GO) with different surface oxygen functional groups was proposed via adjusting the Femi energy level of electrode.After careful characterization of the prepared samples,the influence of surface oxygen functional groups,defects,conductivity and surface charges of the modified electrodes on the electrochemistry of electrochemical probes including dopamine,Fe(CN)6]3 andβ-nicotinamide adenine dinucleotide disodium salt hydrate (NADH,reduced form) was studied.It was found that the electrochemically reduced graphene had a large number of defects and rich functional groups when the reduction extent of graphene oxide was low,which could promote the self-catalysis of dopamine and electron transfer of K3 Fe (CN)6].At more negative reduction potentials,most of the oxygenated functional groups would be reduced,which could reduce the adsorption of NAD+,as a result,the electrochemical oxidation of NADH was accelerated due to the decreased electrode fouling.