Mesoporous graphitic carbon nitride (g-C₃N₄) with open channels and high electron transport properties is in the limelight to serve as a catalyst support for environmental and energy applications. Herein, we have developed novel and environmentally friendly Fe/Ni@g-C₃N₄ nanocomposites for dual application in hydrodechlorination of trichloroethylene (TCE) and the consecutive oxygen reduction reaction (ORR). A homogeneous distribution of 2–3 nm Ni nanoparticles aligned onto the Fe⁰ nanoparticles is observed to form bimetallic Fe/Ni nanocomposites. The decoration of Fe/Ni onto a few layers of lamellar g-C₃N₄ provides large surface area and accelerated electron transfer properties, resulting in the enhanced hydrodechlorination efficiency and rate of TCE. An 8-fold increase in the rate constant for TCE dechlorination by Fe/Ni@g-C₃N₄ is observed when the external voltage of −0.4 V is applied. Moreover, the generated iron oxides on the surface of Fe/Ni@g-C₃N₄ after the dechlorination exhibit superior electrocatalytic ORR activity with an electron transfer number of 3.9. In addition, the current density and onset potential of Fe/Ni@g-C₃N₄ are 3.6 mA cm⁻² and 0.84 V, respectively, which are close to those of standard Pt/C electrode materials. Results obtained in this work clearly demonstrate the excellence of Ni/Fe@g-C₃N₄ nanocomposites in consecutive applications to dechlorination and the ORR, which can open an avenue to design multifunctional metal@carbon nanocomposites as excellent electrochemical activity materials for water-energy nexus applications.

中文翻译：

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功能化的Fe / Ni @ g-C3N4纳米结构，可增强三氯乙烯的脱氯作用和连续的氧还原反应活性

具有开放通道和高电子传输性能的中孔石墨碳氮化物（gC ₃ N ₄）成为人们关注的环境和能源应用的催化剂载体。在这里，我们已经开发出新颖且环保的Fe / Ni @ gC ₃ N ₄纳米复合材料，可用于三氯乙烯的加氢脱氯（TCE）和连续的氧还原反应（ORR）。观察到在Fe ⁰纳米颗粒上排列的2–3 nm Ni纳米颗粒的均匀分布，形成了双金属Fe / Ni纳米复合材料。Fe / Ni在几层片状gC ₃ N ₄上的装饰具有较大的表面积和加速的电子转移性能，从而提高了加氢脱氯效率和三氯乙烯的转化率。当施加-0.4 V的外部电压时，观察到Fe / Ni @ gC ₃ N ₄对TCE脱氯的速率常数增加了8倍。而且，脱氯后在Fe / Ni @ gC ₃ N ₄表面上生成的氧化铁表现出优异的电催化ORR活性，电子转移数为3.9。此外，Fe / Ni @ gC ₃ N ₄的电流密度和起始电位为3.6 mA cm ^-2和0.84 V，分别接近标准Pt / C电极材料。这项工作获得的结果清楚地证明了Ni / Fe @ gC ₃ N ₄纳米复合材料在连续用于脱氯和ORR中的卓越表现，这可以为设计多功能金属@碳纳米复合材料作为水能联系的优良电化学活性材料开辟一条道路。应用程序。