Dissolved organic matter source-dependent ROS dynamics in covalent triazine framework photocatalysis

HA greatly suppresses ·OH and halves 1 O 2 formation compared with plastic-derived DOM. • PS-DOM shows over threefold stronger ·O 2 − inhibition than PE-DOM. • Aromatic ketones in plastic-derived DOM prolong 3 DOM ⁎ lifetime while HA moieties quench ROS. • Energy and electron transfer pathways define DOM-controlled ROS dynamics. Porous carbon-based photocatalysts offer a promising platform for visible light-driven water treatment, yet dissolved organic matter (DOM) from natural and anthropogenic sources can substantially modulate reactive oxygen species (ROS) dynamics, affecting pollutant degradation. A systematic understanding of how DOM composition and molecular structure influence ROS generation remains limited. Here, a boron-doped covalent triazine framework (B-CTF) was employed as a model photocatalyst, with humic acid (HA) and microplastic-derived DOM (PE-DOM, PS-DOM) representing natural and anthropogenic coexisting components. Adsorption experiments revealed that B-CTF exhibited enhanced maximum adsorption capacities ( q m ) for HA, PE-DOM, and PS-DOM and accelerated intraparticle diffusion, demonstrating efficient DOM-catalyst interfacial interactions. ROS analysis identified 1 O 2 and ·OH as dominant species, strongly modulated by DOM. HA suppressed ·OH generation by 2.00 × 10 −2  h −1 , ∼1.0 order of magnitude higher than PE-DOM and PS-DOM, and reduced 1 O 2 formation nearly twofold relative to plastic-derived DOM. PS-DOM caused the strongest ·O 2 − inhibition (8.34 × 10 −2  h −1 , 3.3-fold higher than PE-DOM), while PE- and PS-DOM moderately suppressed overall ROS. Fluorescence component analysis indicated that aromatic ketones in plastic-derived DOM facilitate ROS persistence, while humic-like substances in HA promote ROS quenching, highlighting the decisive role of DOM composition in interfacial ROS regulation. These findings elucidate the mechanistic pathways by which distinct DOM types regulate energy and electron transfer at the B-CTF interface, thereby controlling ROS yields, lifetimes, and spatial distribution. They also provide quantitative guidance for designing DOM-resilient photocatalysts and developing targeted water treatment strategies. Natural and anthropogenic DOM (HA, PE-DOM, PS-DOM) critically regulate ROS formation, reactivity, and persistence in B-CTF photocatalytic systems via distinct energy- and electron-transfer pathways. Specific structural components within DOM quench or sustain ROS, thereby reshaping degradation routes and pollutant removal efficiency. These mechanistic insights highlight the structure-activity relationship governing DOM + B-CTF interactions and provide guidance for developing photocatalysts with resilience to DOM interferences in complex aquatic environments. Download: Download high-res image (154KB) Download: Download full-size image