Synergistic modulation of phase and doping in Co-N-MoS₂ heterojunctions for pathway-modulated ROS evolution in PMS...

Achieving controlled pathway modulation of reactive oxygen species (ROS) generation during peroxymonosulfate (PMS) activation is a pivotal challenge. Herein, we report a CoN co-doped MoS₂ catalyst with a 1 T/2H heterophase (N-Co-MoS₂) to elucidate the impact of doping and phase engineering on ROS evolution during PMS activation. Characterizations reveal that CoN synergy stabilizes the metallic 1 T phase (47.91%) and enriches graphitic N (31.15%), generating electron-rich Co-N_x sites that facilitate PMS adsorption and OO bond elongation. Crucially, phase/doping modulation steers ROS distribution. While pristine MoS₂ follows mixed pathways, single Co-doping shifts dominance to ¹O₂ (42.36%). The N-Co-MoS₂ heterostructure yields a balanced ROS composition with ¹O₂ (31.44%), O₂^•- (27.83%), •OH (26.91%), and SO₄^•- (13.82%), accompanied by a marked increase in the steady-state concentration of ¹O₂. This is attributed to the synergy between the 1 T-phase electron highway and the regenerative Co/Mo redox cycle. The system also demonstrates effective pollutant detoxification, excellent stability in real water matrices, and promising continuous-flow performance, establishing a clear design principle for pathway-modulated catalysis through electronic structure engineering.