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

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.