Department of Chemical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016, India.
Center for Environmental Science and Engineering, Indian Institute of Technology Kanpur, Kanpur 208016, India.
Chemosphere. 2020 Jun;248:126030. doi: 10.1016/j.chemosphere.2020.126030. Epub 2020 Jan 27.
Gradually increasing concentrations of diclofenac (DCF), a widely used anti-inflammatory drug, in water bodies is an emerging concern because of the persistent characteristics and harmful environmental impact of the drug molecule. In this study, electro-oxidation using a novel copper (Cu) - reduced graphene oxide (rGO) electrode is indicated to be an efficient technology for treating DFC-laden wastewater. The Cu-rGO dispersed carbon film (∼1 mm thickness) is synthesized by carbonization and H-reduction of a phenolic polymeric film in situ dispersed with a Cu salt and GO. The synthesized self-standing carbon film electrode is used for electro-oxidation of aqueous DCF. Analytical microscopic techniques are used to study the physicochemical properties of the material. Cyclic voltammetry analysis shows the prepared electrode generating a high oxidative current response. Approximately 100% DCF degradation is measured within 1 h at 1 V constant biased potential. Dual roles of Cu-rGO are presented as rGO facilitating direct oxidation via enhanced electron mobility at the electrode surface and Cu nanoparticles (NPs) participating in indirect oxidation by generating OH radicals in aqueous phase. The Cu NPs show an over-potential of -0.5 V vs. Ag/AgCl (100 mM KCl) for oxygen evolution, indicating indirect oxidation of DCF. The high non-faradic current density of 4 mA cm generated at the positive potential (1 V) indicates direct oxidation of DCF. This study clearly indicates electro-oxidation using the Cu-rGO-dispersed carbon film electrode to be an efficient technique for remediation of pharmaceutical pollutants-contaminated wastewater.
水体中广泛使用的抗炎药物双氯芬酸（DCF）浓度逐渐增加，这是一个新出现的问题，因为该药物分子具有持久性特征和对环境的有害影响。在这项研究中，使用新型铜（Cu）还原氧化石墨烯（rGO）电极的电氧化被表明是处理含 DCF 废水的有效技术。Cu-rGO 分散碳膜（约 1mm 厚）是通过原位碳化和 H 还原酚醛聚合物薄膜合成的，该薄膜中分散有 Cu 盐和 GO。合成的自支撑碳膜电极用于电氧化水溶液中的 DCF。采用分析显微镜技术研究材料的物理化学性质。循环伏安分析表明，所制备的电极产生高氧化电流响应。在 1V 恒偏压下，大约 100%的 DCF 在 1 小时内降解。Cu-rGO 具有双重作用，即 rGO 通过增强电极表面的电子迁移率促进直接氧化，而 Cu 纳米颗粒（NPs）通过在水相中生成 OH 自由基参与间接氧化。Cu NPs 的析氧过电位为-0.5V 相对于 Ag/AgCl（100mM KCl），表明 DCF 的间接氧化。在正电位（1V）下产生的 4mA cm 的高非 Faradaic 电流密度表明 DCF 的直接氧化。这项研究清楚地表明，使用 Cu-rGO 分散碳膜电极的电氧化是修复受药物污染物污染的废水的有效技术。
