Interface engineering in 2D/0D/2D COF@TiO2/MXene S-scheme heterojunction: Decipher charge pathways for antibiotic removal and H2O2 production

Abstract

Interface engineering is gradually emerging as a rational protocol for constructing efficient heterojunction interfaces. In this work, MXene nanosheets, as a platform for in situ growth of ultrafine TiO₂ and simultaneously the confined microenvironment for the decoration of Schiff-base COF, was employed to construct a ternary heterojunction COF@TiO₂/MXene for promoting 2D/0D/2D interface interactions. The optimized heterojunction contributed highly elevated reaction kinetics of up to 0.03423 min⁻¹ for antibiotic degradation along with 69.7 % of mineralization rate under visible light, which were further strengthened to 0.04326 min⁻¹ through photocatalytic self-fenton process due to its commendable H₂O₂ generation capacity. In situ XPS and DFT calculations revealed the formation of S-scheme heterojunction, so as to achieve sufficient production of reactive oxygen species. It is believed that such bi-functional heterojunction possesses an anticipated potential in environmental remediation and solar energy conversion, driving the advancement of S-scheme heterojunctions.