High 1 T-phase molybdenum disulfide induced by L-cysteine as cocatalyst for Fenton-like reaction to enhance organic pollutant degradation

Molybdenum disulfide (MoS₂) is a promising inorganic co-catalyst for Fenton processes due to its structural durability and avoidance of secondary organic pollution. However, the conventional 2H-phase MoS₂ suffers from intrinsically low conductivity, severely limiting Fe 3+ reduction in the Fenton reaction. Herein, L-cysteine served as a multifunctional precursor during the preparation of MoS₂, promoting a slow-release sulfur supply, carbon‑nitrogen co-doping, and the prevention of restacking. The carbon and nitrogen co-doped molybdenum disulfide (CN-MoS 2 ) architecture was fabricated via a single-step hydrothermal reaction mediated by sodium molybdate, thiourea, and L-cysteine. Remarkably, benefiting from the introduction of L-cysteine, the resulting CN-MoS 2 exhibited a high 1 T-phase content (68%), abundant sulfur vacancies, and a substantially reduced particle size. CN-MoS 2 accomplished near-complete elimination of carbamazepine (CBZ) within merely 3 min, yielding a prominent apparent rate constant of 0.7111 min −1 , which is a 19-fold kinetic acceleration over thiourea-derived MoS 2 . CN-MoS₂ also exhibited high TOC removal, broad-spectrum degradation, and robust CBZ removal under various water conditions. Additionally, electrochemical analyses further verified that CN-MoS₂ reduced charge-transfer resistance and enriched electron density, thereby facilitating rapid electron shuttling to Fe 3+ . Concurrently, quenching experiments and electron paramagnetic resonance (EPR) diagnostics unambiguously validated SO 4 •- , 1 O 2 and O 2 •- as the driving reactive forces. Moreover, a continuous-flow device incorporating a CN-MoS 2 -based membrane exhibited outstanding performance in wastewater purification. This work offers a new strategy for designing high-activity co-catalysts for advanced oxidation processes.