Confined-expansion strategy of energetic MOF-derived 1D carbon nanofibers for ultraefficient ozone catalysis: unraveling preparation and mechanistic insights.

Ozone oxidation technology has emerged as a highly effective advanced oxidation process for water treatment, demonstrating remarkable efficiency in degrading persistent and hazardous organic pollutants. However, the traditional single ozone system suffers from the problem of low efficiency, which seriously limits its practical application. We developed a confined expansion pore-making strategy using high-energy MOFs (MET-6), in which metal acetylacetonates (Mn(acac)₂, Fe(acac)₃, Co(acac)₂) were doped into a MET-6 matrix and pyrolyzed under controlled conditions to yield hierarchically porous Mn-, Fe-, and Co-MPC-9 carbon nanofiber. Characterization revealed that the confined pyrolysis induced directional expansion of the MET-6 framework, generating a 3D interconnected pore structure rich in meso- and macropores. For the degradation of Sulfamethoxazole (SMT), Mn-MPC-9 exhibited outstanding catalytic activity, achieving 92 % removal within 20 min with a rate constant (k) of 0.13 min-1, significantly surpassing reference catalysts. The superior performance was attributed to: (i) the 1D nanofiber morphology enhancing surface area and active-site accessibility, (ii) the MET-6-derived carbon skeleton ensuring structural/chemical stability, and (iii) the multilevel pores facilitating ozone diffusion and activation. This work not only presents a novel approach to designing high-efficiency ozone catalysts but also expands the potential of 1D MOF-derived nanomaterials in environmental applications.