Local O2 concentrating boosts the electro-Fenton process for energy-efficient water remediation

• 成果类型: Article
• 署名作者: Xu, Bincheng; Lin, Ze; Li, Fengting; Tao, Tao; Zhang, Gong; Wang, Ying
• 署名单位: Tongji University; Shanghai Institute of Pollution Control & Ecological Security; Tsinghua University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-8653
• DOI: 10.1073/pnas.2317702121
• 发表日期: 2024-03-12
• 关键词: hydrogen-peroxide; h2o2 production; diffusion; oxygen; generation; impedance; single; plant; atom

摘要

The electro-Fenton process is a state-of-the-art water treatment technology used to remove organic contaminants. However, the low O-2 utilization efficiency (OUE, <1%) and high energy consumption remain the biggest obstacles to practical application. Here, we propose a local O-2 concentrating (LOC) approach to increase the OUE by over 11-fold compared to the conventional simple O-2 diffusion route. Due to the well-designed molecular structure, the LOC approach enables direct extraction of O-2 from the bulk solution to the reaction interface; this eliminates the need to pump O-2/air to overcome the sluggish O-2 mass transfer and results in high Faradaic efficiencies (similar to 50%) even under natural air diffusion conditions. Long-term operation of a flow-through pilot device indicated that the LOC approach saved more than 65% of the electric energy normally consumed in treating actual industrial wastewater, demonstrating the great potential of this system-level design to boost the electro-Fenton process for energy-efficient water remediation. Significance The electro-Fenton process which generates reactive oxygen species by O-2 reduction is one promising approach for water remediation, but to guarantee adequate O-2 supply, energy-intensive aeration is always needed, greatly increasing the costs for industrialization. Herein, inspired by the respiratory systems of fish, we developed a local O-2 concentrating (LOC) strategy to increase O-2 utilization efficiency (OUE) by in situ constructing O-2 concentrating reticular frameworks (RF) on the cathode. Amino-functionalization of RF further enhanced the interactions between organic linkers and O-2 molecules, rendering the cathode much higher OUE. The LOC approach represents an innovative, simple, yet effective strategy for reducing or even eliminating the need for an external O-2 supply, providing a conceptual advance to design an energy-efficient electro-Fenton process.