Zhou Huaxu, Dong Guotao, Sailjoi Ajabkhan, Liu Jiyang
Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018, China.
Heihe Water Resources and Ecological Protection Research Center, Lanzhou 730030, China.
Nanomaterials (Basel). 2021 Dec 27;12(1):65. doi: 10.3390/nano12010065.
Three-dimensional graphene (3DG) with macroporous structure has great potential in the field of electroanalysis owing to a large active area, excellent electron mobility and good mass transfer. However, simple and low-cost preparation of 3DG electrodes with high electrocatalytic ability is still a challenge. Here, a fast and convenient electrochemical polarization method is established to pretreat free-standing 3DG (p-3DG) to offer high electrocatalytic ability. 3DG with monolithic and macroporous structure prepared by chemical vapor deposition (CVD) is applied as the starting electrode. Electrochemical polarization is performed using electrochemical oxidation (anodization) at high potential (+6 V) followed with electrochemical reduction (cathodization) at low potential (-1 V), leading to exposure of edge of graphene and introduction of oxygen-containing groups. The as-prepared p-3DG displays increased hydrophilicity and improved electrocatalytic ability. As a proof of concept, p-3DG was used to selective electrochemical detection of two isomers of benzenediol, hydroquinone (p-BD) and catechol (o-BD). In comparison with initial 3DG, p-3DG exhibits increased reversibility of redox reaction, improved peak current and good potential resolution with high potential separation between p-BD and o-BD. Individual or selective determination of p-BD or o-BD in single substance solution or binary mixed solution is realized. Real analysis of pond water is also achieved.
具有大孔结构的三维石墨烯（3DG）由于具有较大的活性面积、优异的电子迁移率和良好的传质性能，在电分析领域具有巨大潜力。然而，制备具有高电催化能力的3DG电极且方法简单、成本低廉仍是一项挑战。在此，我们建立了一种快速便捷的电化学极化方法来预处理独立式3DG（p-3DG），以赋予其高电催化能力。采用化学气相沉积（CVD）法制备的具有整体式和大孔结构的3DG作为起始电极。通过在高电位（+6 V）下进行电化学氧化（阳极氧化），随后在低电位（-1 V）下进行电化学还原（阴极化）来进行电化学极化，从而使石墨烯边缘暴露并引入含氧基团。所制备的p-3DG表现出增加的亲水性和改善的电催化能力。作为概念验证，p-3DG被用于对苯二酚的两种异构体对苯二酚（p-BD）和邻苯二酚（o-BD）进行选择性电化学检测。与初始3DG相比，p-3DG表现出氧化还原反应可逆性增强、峰电流提高以及良好的电位分辨率，p-BD和o-BD之间具有高电位分离。实现了在单物质溶液或二元混合溶液中对p-BD或o-BD的单独或选择性测定。还实现了对池塘水的实际分析。
