Regulating crystallinity in cellulose substrate to construct highly and homogeneously dispersed TiO2 for tetracycline hydrochloride adsorption

This work developed a simple and mild strategy for controllable synthesis of highly and homogeneously distributed TiO 2 nanoparticles on a cellulose template via tuning the cellulose crystallinity. As the crystallinity of cellulose increases, the restriction from crystallinity on nanoparticles increases, leading to homogeneous distribution, a decrease in size, and structural changes of TiO 2 from crystalline to amorphous. The carboxyl groups grafted on the periodically arranged hydroxyl groups of crystalline cellulose, which act as anchor sites for metal oxide precursor, restrict the distribution, growth and crystallization of TiO 2 nanoparticles. The amorphous TiO 2 nanoparticles on the cellulose with the highest degree of crystallinity (72.40 %) give the highest adsorption capacity toward tetracycline hydrochloride (152.89 mg/g), which is the state of art among the supported TiO 2 . The high adsorption capacity is proposed to be the oxygen defects caused by the Ti 3+ species, originating from the amorphous TiO 2 nanoparticles.