Single-atom/defect-interface drives synergistic photothermal oxidation of long-chain alkanes from cooking emissions

Cooking fumes pose threats to ecological health and have a complex composition, among which long-chain alkanes are hard to be removed via the deep oxidation. Synergistic photothermal catalysis provides an efficient and energy-saving approach. Yet, the synergistic interplay of multiple active sites and the bond-cleavage dynamics are not fully understood. In this study, the Pt 1 /Co 3 O 4 /GCN (GCN refers to two-dimensional ultrathin graphitic g-C 3 N 4 nanosheets) catalyst was obtained by modifying a p-n heterojunction with trace (0.05 wt%) Pt single atoms via electrostatic self-assembly and in-situ ice crystal-assisted photoreduction strategy. Under the photothermal reaction condition, the T 90% for the catalytic oxidation of 3000 ppm heptane was as low as 195 °C, and its high TOF Pt value (0.053 s –1 ) indicated that the present catalyst outperformed most Pt-based materials. By integrating in-situ spectroscopy and kinetic analysis, the synergistic mechanism between photogenerated carrier separation and thermal effects was uncovered. The built-in electric field of the Co 3 O 4 /GCN heterojunction drives the directional separation of charges, accelerating the generation of ·O 2 ⁻. Furthermore, interfacial interactions induce the formation of oxygen vacancies (O v ) on the Co 3 O 4 side, enhancing the adsorption capacity for reactants. The Pt 1 sites and O v collaboratively optimize the C–H bond activation and C–C bond cleavage pathways, promoting the reaction towards deep oxidation. This study introduces a single-atom/defect-interface synergistic strategy, providing a novel perspective for the rational design of high-performance and stable photothermal catalysts for VOCs abatement.