Hierarchically Structured NH2‐MIL‐125/TiO2/Cellulose Composite Membranes With Enhanced Photocatalytic Performance

Hierarchical nanofibrous MOF/TiO₂/cellulose composite membranes were fabricated, showing enhanced photocatalytic performances towards the photodegradation of RhB under UV light.

Abstract

A cellulose-based photocatalytic membrane was fabricated by in situ growth of the NH₂-MIL-125 nanoparticles onto the surfaces of the ultrathin titania (TiO₂) gel layers pre-coated cellulose nanofibres of natural cellulose substance (commercial laboratory filter paper). The NH₂-MIL-125 nanoparticles were grown on the surface of the titania gel coated cellulose nanofibres via a one-step solvothermal method. The resultant composite membranes maintained the initial hierarchical network structures of the bulk cellulose substance, consisting titania gel layer coated cellulose nanofibres with NH₂-MIL-125 nanoparticles anchored on the surfaces. Owing to the hierarchical porous structure of the cellulose substrates as well as the effective heterostructure formation between the NH₂-MIL-125 particles and the TiO₂ layers, the composites showed enhanced photocatalytic performances. The NH₂-MIL-125/TiO₂/cellulose composite composed of 15.82 wt% NH₂-MIL-125 content with nanoparticles sizes of 100–200 nm showed an apparent rate constant of 0.032 min⁻¹ in photocatalytic degradation of Rhodamine B (RhB), which was higher than those of the NH₂-MIL-125/cellulose composite and the TiO₂/cellulose composite. It was demonstrated that pre-coating of the cellulose nanofibres with ultrathin titania gel layers was essential for the growth of the NH₂-MIL-125 nanoparticles thereon.

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