School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China.
School of Metallurgy, Northeastern University, Shenyang, 110819, China.
Environ Pollut. 2024 Jun 15;351:124090. doi: 10.1016/j.envpol.2024.124090. Epub 2024 Apr 30.
Indoor formaldehyde poses a significant carcinogenic risk to human health, making its removal imperative. Electro-Fenton degradation has emerged as a promising technology for addressing this concern. In the electro-Fenton system, ·OH is identified as the primary active species responsible for formaldehyde removal. Hence, its generation and utilization are pivotal for the system's effectiveness and economy. Experimental and quantum chemical methods were employed to investigate the effects and mechanisms of nitrogen doping on various aspects influencing ·OH generation and utilization. Results indicate that nitrogen doping synergistically enhances the generation and utilization of ·OH, leading to an improved formaldehyde removal efficiency in nitrogen-doped cathodic systems. The dominant nitrogen type influencing ·OH generation and utilization varies across different stages. Pyridinic nitrogen facilitates HO adsorption through hydrogen bonding, while pyrrolic and graphitic nitrogen contribute to formaldehyde adsorption and catalyze the conversion of HO to ·OH. Both pyridinic nitrogen and pyrrolic nitrogen boost the degradation of formaldehyde by ·OH. In comparison to the unmodified system, the modified system with NAC-GF/700C as cathode exhibits remarkable improvements. The formaldehyde removal efficiency has increased twofold, and energy consumption reduced by 73.45%. Furthermore, the system demonstrates excellent cyclic stability. These advancements can be attributed to the activation temperature, which leads to the appropriate types and high content of nitrogen elements in NAC-GF/700C. The research represents an important step towards more economical and efficient electro-Fenton technology for indoor formaldehyde removal.
室内甲醛对人体健康构成重大致癌风险，因此必须加以清除。电芬顿降解技术已成为解决这一问题的一种有前途的技术。在电芬顿系统中，·OH 被确定为去除甲醛的主要活性物质。因此，其生成和利用对于系统的有效性和经济性至关重要。本研究采用实验和量子化学方法，研究了氮掺杂对影响·OH 生成和利用的各个方面的影响和机制。结果表明，氮掺杂协同增强了·OH 的生成和利用，从而提高了氮掺杂阴极系统中甲醛的去除效率。不同阶段影响·OH 生成和利用的主要氮类型不同。吡啶氮通过氢键促进 HO 的吸附，而吡咯氮和石墨氮促进甲醛的吸附，并催化 HO 转化为·OH。吡啶氮和吡咯氮都能促进·OH 降解甲醛。与未改性系统相比，NAC-GF/700C 作为阴极的改性系统表现出显著的改善。甲醛去除效率提高了两倍，能耗降低了 73.45%。此外，该系统还表现出优异的循环稳定性。这些改进可归因于活化温度，这导致了 NAC-GF/700C 中适当类型和高含量的氮元素。这项研究是朝着更经济、更高效的室内甲醛去除电芬顿技术迈出的重要一步。
