Development of MoS₂-stainless steel catalyst by 3D printing for efficient destruction of organics via...

Herein, a novel MoS₂-stainless steel composite material was first synthetized via a 3D printing method (3DP MoS₂-SS) for peroxymonosulfate (PMS) activation and organics degradation. Compared with MoS₂-SS powder/PMS system (0.37 g/(m²/min)), 4.3-fold higher k_FLO/S_BET value was obtained in 3DP MoS₂-SS/PMS system (1.60 g/(m²/min), resulting from the superior utilization of active sites. We observed that 3DP MoS₂-SS significantly outperformed the 3DP SS due to the enhanced electron transfer rate and increased active sites. Moreover, Mo⁴⁺ facilitated the Fe²⁺/Fe³⁺ cycle, resulting in the rapid degradation of florfenicol (FLO). Quenching experiments and electron paramagnetic resonance spectra indicated that •OH, SO₄•^-, O₂•^- and ¹O₂ were involved in the degradation of FLO. The effect of influencing factors on the degradation of FLO were evaluated, and the optimized degradation efficiency of 98.69% was achieved at 1 mM PMS and pH of 3.0. Six degradation products were detected by UPLC/MS analyses and several possible degradation pathways were proposed to be the cleavage of C-N bonds, dechlorination, hydrolysis, defluorination and hydroxylation. In addition, 3DP MoS₂-SS/PMS system also demonstrated superior degradation performance for 2-chlorophenol, acetaminophen, ibuprofen and carbamazepine. This study provided deep insights into the MoS₂-SS catalyst prepared by 3DP technology for PMS activation and FLO-polluted water treatment.