Facilitating carrier kinetics in ultrathin porous carbon nitride through shear-repair strategy for peroxymonosulfate-assisted water purification.

Liu, Hao; Yang, Bin; Liao, Guangfu; Huang, Baoyu; Li, Jun; Rodriguez, Raul D; Jia, Xin · Nat Commun · 2025

basic_science · Level V

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Abstract

Achieving high specific surface area (HSSA) in graphitic carbon nitride (g-C<sub>3</sub>N<sub>4</sub>) severely depolymerizes the molecular chain structure, resulting in sluggish carrier kinetic behaviors and thus moderated water purification performance in photocatalytic peroxymonosulfate (PMS) activation system. Herein, we report a versatile shear-repair strategy for fabricating ultrathin porous g-C<sub>3</sub>N<sub>4</sub> nanosheets with a thickness of 1.5 nm, HSSA (138.5 m<sup>2</sup> g<sup>-1</sup>), and highly polymerized molecular chains. This strategy accelerates exciton dissociation and charge carrier separation, with the exciton binding energy decreasing from 65.7 to 47.5 meV. Crucially, the electron-donating pollutant and electron-withdrawing PMS generate a microelectric field at the g-C<sub>3</sub>N<sub>4</sub> surface that activates PMS to generate <sup>1</sup>O<sub>2</sub> sustainably. Consequently, our catalyst exhibits an exceptional imidacloprid (IMD) removal performance with a rate constant of 0.405 min<sup>-1</sup> and remarkable PMS utilization efficiency (90% within 15 min). Moreover, under real conditions of sunlight irradiation, we observe an outstanding pollutants' removal efficiency with a near-100% degradation rate over 20 days of continuous operation. Our work emphasizes the feasibility of synergistic molecular-level structural engineering for refining carrier kinetic behaviors in high-performance photocatalyst design.