Advances in iron-based electrocatalysts for nitrate reduction

Excessive nitrate has been a critical issue in the water environment, originating from the burning of fossil fuels, inefficient use of nitrogen fertilizers, and discharge of domestic and industrial wastewater. Among the effective treatments for nitrate reduction, electrocatalysis has become an advanced technique because it uses electrons as green reducing agents and can achieve high selectivity through cathode potential control. The effectiveness of electrocatalytic nitrate reduction (NO3RR) mainly lies in the electrocatalyst. Iron-based catalysts have the advantages of high activity and low cost, which are well-used in the field of electrocatalytic nitrates. A comprehensive overview of the electrocatalytic mechanism and the iron-based materials for NO3RR are given in terms of monometallic iron-based materials as well as bimetallic and oxide iron-based materials. A detailed introduction to NO3RR on zero valent iron, single-atom iron catalysts, and Cu/Fe-based bimetallic electrocatalysts are provided, as they are essential for the improvement of NO3RR performance. Finally, the advantages of iron-based materials for NO3RR and the problems in current applications are summarized, and the development prospects of efficient iron-based catalysts are proposed.

Automated summary

Excessive nitrate in water is a significant problem caused by fossil fuel combustion, inefficient nitrogen fertilizer use, and wastewater discharge. Electrocatalysis, utilizing electrons as green reducing agents, has become an effective method for nitrate reduction due to its high selectivity through cathode potential control. Iron-based catalysts, with advantages of high activity and low cost, are widely used in electrocatalytic nitrate reduction. This article provides a comprehensive overview of the electrocatalytic mechanism and iron-based materials for nitrate reduction, including monometallic iron-based materials, bimetallic iron-based materials, and iron oxide-based materials. It also focuses on the introduction of zero valent iron, single-atom iron catalysts, and Cu/Fe-based bimetallic electrocatalysts, which are essential for improving the performance of nitrate reduction. Finally, the advantages of iron-based materials for nitrate reduction and the current problems in applications are summarized, and the development prospects of efficient iron-based catalysts are proposed.