Defective S/N co-doped carbon cloth via a one-step process for effective electroreduction of nitrogen to ammonia

Abstract

The electroreduction of nitrogen (N₂) has gained increasing attention as a promising route to achieve green and sustainable ammonia (NH₃) production. However, the construction of an active and durable electrocatalyst for N₂ reduction reaction (NRR) remains a significant challenge. Herein, we, for the first time, report that S/N co-doped carbon cloth (CC) with abundant defects can serve as an efficient NRR electrocatalyst at ambient conditions. The S/N co-doped CC was prepared through a novel one-step method by using ammonium persulfate (APS) as the source of nitrogen and sulfur. The catalyst prepared at 800 °C (CC-APS 800) showed abundant defects and heteroatoms as the active and stable electrocatalytic sites for NH₃ electrosynthesis. Based on this, a sizeable NH₃ yield of 9.87 × 10⁻¹⁰ mol s⁻¹ cm⁻² and high faradaic efficiency of 8.11% were obtained in 0.05 M H₂SO₄ at −0.3 V (vs. reversible hydrogen electrode, RHE), respectively. Furthermore, the electrocatalytic mechanism on CC-APS 800 was elucidated using the electrochemical in situ Fourier transform infrared technique, and follows an associative reaction pathway. Our work would provide a new guideline for designing metal-free self-standing electrocatalysts for the NRR and other applications.