Carbonized Ce/Cu Metal–Organic Framework-Derived Porous Nanorods for High-Performance Adsorption of Organic Pollutants

Metal-organic framework (MOF)-derived materials have attracted growing interest for wastewater treatment, owing to their tunable compositions and structural versatility. In this study, bimetallic cerium/copper benzene-1,3,5-tricarboxylate (Ce/Cu-BTC) nanofibers were synthesized at room temperature using sodium-BTC (Na-BTC) as the organic linker, followed by carbonization to obtain a Cu-doped CeO₂/C hybrid material (denoted as Ce/Cu-BTC-C). The adsorption performance of both Ce/Cu-BTC and Ce/Cu-BTC-C toward Congo red (CR) and methyl blue (MB) was systematically evaluated. The Ce/Cu-BTC-C adsorbent exhibited markedly enhanced adsorption capacities and reached 1460.4 mg·g⁻¹ for CR and 1906.9 mg·g⁻¹ for MB, approximately 18.4- and 17.7-fold higher than those of the pristine Ce/Cu-BTC precursor (79.4 mg·g⁻¹ and 107.6 mg·g⁻¹, respectively). The significant improvement is attributed to carbonization-induced structural rearrangement and the increased exposure of redox-active Ce/Cu sites, as confirmed by XPS analysis. Kinetic results indicate that CR adsorption follows a pseudo-first-order model, whereas MB adsorption fits a pseudo-second-order model, consistent with distinct interaction strengths. The Ce/Cu-BTC-C adsorbent also demonstrated good reusability, retaining over 85% of its initial adsorption capacity after five successive regeneration cycles. Overall, this work provides an effective room-temperature synthetic route for producing MOF-derived metal-oxide/carbon hybrids with strong potential for organic dye removal.