Wang Jing, Ling Lan, Deng Zilong, Zhang Wei-Xian
State Key Laboratory for Pollution Control, School of Environmental Science and Engineering, Shanghai Institute of Pollution Control and Ecological Security, Tongji University, Shanghai 200092, China.
State Key Laboratory for Pollution Control, School of Environmental Science and Engineering, Shanghai Institute of Pollution Control and Ecological Security, Tongji University, Shanghai 200092, China.
Sci Bull (Beijing). 2020 Jun 15;65(11):926-933. doi: 10.1016/j.scib.2020.02.015. Epub 2020 Feb 19.
Nitrate is the leading cause of eutrophication worldwide and is one of the most challenging pollutants for restoration of polluted surface waters such as lakes, rivers and reservoirs. We report herein a new architecture of iron nanoparticles for high-efficiency denitrification by selective reduction of nitrate (NO) to dinitrogen (N). The iron nanoparticles are doped with nitrogen (FeN) and encapsulated within a thin layer of nitride-carbon (NC). The nanoparticles have high pyrrolic N content (17.4 at.%) and large specific surface area (2040 m/g). Laboratory experiments demonstrated high N selectivity (91%) and nitrate removal capacity (6004 mg N/g Fe) for treatment of nitrate-containing water. This iron-based nanomaterial overcomes shortcomings of conventional catalysts by eliminating the use of precious and toxic heavy metals (e.g., Pd, Pt, Cu, Ni) and minimizing the generation of undesirable byproducts (e.g., ammonia) from the reactions with nanoscale zero-valent iron (nZVI). The multiple electron transfers process from NO to N can be fine-tuned by adjusting the NC shell thickness. Superior electrocatalytic performance, low cost and minimal environmental impact of the iron-derived nanocatalyst offer promising prospects for water purification, waste treatment and environmental remediation.
硝酸盐是全球范围内富营养化的主要原因，也是湖泊、河流和水库等受污染地表水修复中最具挑战性的污染物之一。我们在此报告一种新型铁纳米颗粒结构，用于通过将硝酸盐（NO）选择性还原为二氮（N₂）来进行高效反硝化。铁纳米颗粒掺杂有氮（FeN）并包裹在一层薄的氮化物 - 碳（NC）中。这些纳米颗粒具有较高的吡咯氮含量（17.4 原子%）和较大的比表面积（2040 m²/g）。实验室实验表明，该材料在处理含硝酸盐的水时具有高氮选择性（91%）和硝酸盐去除能力（6004 mg N/g Fe）。这种铁基纳米材料克服了传统催化剂的缺点，无需使用珍贵且有毒的重金属（如 Pd、Pt、Cu、Ni），并最大限度地减少了与纳米级零价铁（nZVI）反应产生的不良副产物（如氨）。通过调整 NC 壳层厚度，可以微调从 NO 到 N₂的多电子转移过程。铁基纳米催化剂卓越的电催化性能、低成本和最小的环境影响为水净化、废物处理和环境修复提供了广阔前景。
