Preparation and photocatalytic performance of TiO2/cellulose aerogel composite materials

Nano-TiO 2 was synthesized by a sol-gel method using tetrabutyl titanate, anhydrous ethanol, and glacial acetic acid as precursors. Subsequently, a TiO 2 /cellulose hydrogel was prepared by in situ polymerization using cellulose and nano-TiO 2 as the matrix materials, ammonium persulfate (APS) as the initiator, and acrylic acid (AA) and acrylamide (AM) as grafting monomers. The obtained hydrogel was converted into a porous aerogel composite by freeze-drying. The structure and surface properties of the composite were systematically characterized by Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Through orthogonal array design and single-factor experiments, three critical parameters affecting the photocatalytic performance were optimized: TiO 2 loading (0.5 g), monomer molar ratio (AM: AA = 1:3.5), and crosslinker dosage (N, N’-methylenebisacrylamide, MBA = 0.04 g). Photocatalytic degradation was evaluated by UV-Vis spectroscopy using methylene blue as a model pollutant. The results showed that the degradation efficiency decreased with increasing methylene blue concentration, whereas the time required to reach equilibrium increased. In comparative experiments, the CQDs/TiO 2 /GO/cellulose aerogel exhibited higher degradation efficiency than the binary TiO 2 /cellulose aerogel, achieving 95.8% methylene blue degradation within 60 min. The composites also showed selective photocatalytic activity, with markedly higher degradation rates for methylene blue than for eriochrome black T and norfloxacin.