Felycia Edi Soetaredjo, Suryadi Ismadji, Shella Permatasari Santoso, Jessica Chrisanta Soegianto, Jindrayani Nyoo Putro, Darwin Kurniawan, Michael Suryananda Ismadji, Alfin Kurniawan, Jenyfer Sugianto
A bifunctional Fe-modified titanium metal–organic framework, MIL-125(Ti)@Fe, was rationally designed to integrate adsorption preconcentration and photo-Fenton degradation for efficient removal of anionic azo dyes from textile wastewater. Structural characterization confirmed that low-level Fe incorporation preserves the MIL-125(Ti) framework while narrowing the band gap from 3.20 to 2.28 eV, thereby extending light absorption into the visible region. Compared with pristine MIL-125(Ti), MIL-125(Ti)@Fe exhibited substantially enhanced adsorption capacities toward CI Direct Blue 1 and CI Direct Yellow 4, as well as near-complete degradation of the residual dye after adsorption equilibrium under UV/visible irradiation in the presence of H2O2. Kinetic analysis revealed pseudo-first-order degradation behavior with thermally assisted reaction rates. The synergistic enhancement arises from adsorption preconcentration coupled with Fe-assisted H2O2 activation, as supported by radical trapping experiments showing an •OH-dominated degradation pathway. Potential interfacial electron-transfer effects are discussed as a plausible contribution rather than as directly confirmed charge-separation evidence. The catalyst retained over 90% of its activity after five consecutive cycles, demonstrating excellent structural robustness. This work establishes a design principle for Fe-assisted Ti-MOF platforms that couple adsorption and photo-Fenton catalysis, offering a sustainable and reusable strategy for advanced wastewater treatment. Unlike conventional Fe oxide-loaded MOFs or photocatalysis-focused Ti-MOF systems, the present low-level Fe-modified MIL-125(Ti) couples high adsorption capacity, •OH-dominated photo-Fenton degradation, low Fe leaching, and stable recyclability within a single framework-preserved material. © The Author(s), under exclusive licence to the Institute of Chemistry, Slovak Academy of Sciences 2026.
Department of Chemical Engineering, Widya Mandala Surabaya Catholic University, Kalijudan 37, Surabaya, 60114, Indonesia; Department of Chemical Engineering, Master Study Program, Widya Mandala Surabaya Catholic University, Kalijudan 37, Surabaya, 60114, Indonesia; Department of Chemical Engineering, National Taiwan University of Science and Technology, No. 43, Section 4, Keelung Rd, Da’an District, Taipei City, 106, Taiwan; Research Group for Advanced Materials and Sustainable Catalysis (AMSC), State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou, 310032, China