Directional electron migration in heteroatom-engineered MoS2 nanoflower structures boosts visible-light photocatalytic purification of sulfonylurea herbicides

Strategic engineering of heteroatomic doping configurations to precisely regulate the directional migration efficiency of photogenerated charge carriers has been demonstrated as a pivotal approach to overcome inherent kinetic limitations in semiconductor-based photocatalytic systems. Li/Co co-doped MoS 2 nanoflower structures (MLC2) were synthesized via a single-step hydrothermal protocol and applied for the photocatalytic degradation of chlorsulfuron in aqueous environments. Density functional theory analysis revealed that Li and Co atoms occupied Mo sites, generating electron-deficient centers that modified photogenerated electron transfer pathways. This strategic doping engineering enhanced charge separation efficiency, as evidenced by transient photocurrent response, electrochemical impedance spectroscopy, and Tafel curves. The optimized MLC2 catalyst demonstrated exceptional degradation performance, achieving 89.72 % chlorsulfuron removal within 360 min under visible light irradiation (λ ≥ 420 nm; 300 W), corresponding to quasi-first-order rate constants (k) 52.46-fold and 3.37-fold higher than those of undoped MoS 2 (k = 1.22 E −4 min −1 ) and Li-MoS 2 (k = 0.0019 min −1 ), respectively. The dominant role of photogenerated electrons, along with their generation and transfer pathways, had been experimentally validated. Furthermore, MLC2 demonstrated considerable potential in practical applications.