High-Efficiency NO conversion via In-Situ grown covalent organic framework on g-C3N4 nanosheets with Single-Atom platinum photocatalyst

This study presents a chemically bonded Pt/TP-BPY-CN/g-C3N4 composite photocatalyst created through an in-situ growth method via Schiff base reaction between g-C3N4 and aldehyde-functionalized TP-BPY-COF. The −H-C-N-H- bonds formed at the g-C3N4 and TP-BPY-COF interface significantly boost electron communication, thereby substantially enhancing transfer efficiency between these two constituents. Besides, single-atom platinum incorporation via coordination establishes a Pt2+/Pt4+ redox cycle, aiding both oxidation and reduction of nitric oxide (NO). Consequently, the Pt/40TPBPY-CN composite achieves 65.3 % NO conversion, with almost 100 % oxidation selectivity towards NO3–. In-situ XPS analysis confirms the robust electron communication between TP-BPY-COF and g-C3N4 facilitated by −H-C-N-H- bonds, and the redox transformation between Pt2+ and Pt4+. In addition, DFT calculation provides a deeper insight into photocatalytic oxidation and reduction pathways, confirming an inhibition of N2 desorption. This research underscores the benefits of chemically bonded heterostructures for improved electronic interactions and highlights the efficacy of bifunctional single-atom platinum in photocatalysis.