A study of TiO2 nanocrystal growth and environmental remediation capability of TiO2/CNC nanocomposites

Green and sustainable cellulose nanocrystals-TiO2 nanocomposite was prepared for environmental applications using a facile method comprised of thermal degradation of aqueous titanium precursors.
Nanocellulose, which can be derived from any cellulosic biomass, has emerged as an appealing nanoscale scaffold to develop inorganic–organic nanocomposites for a wide range of applications. In this study, titanium dioxide (TiO2) nanocrystals were synthesized in the cellulose nanocrystal (CNC) scaffold using a simple approach, i.e., hydrolysis of a titanium oxysulfate precursor in a CNC suspension at low temperature. The resulting TiO2 nanoparticles exhibited a narrow size range between 3 and 5 nm, uniformly distributed on and strongly adhered to the CNC surface. The structure of the resulting nanocomposite was evaluated by transmission electron microscopy (TEM) and X-ray diffraction (XRD) methods. The growth mechanism of TiO2 nanocrystals in the CNC scaffold was also investigated by solution small-angle X-ray scattering (SAXS), where the results suggested the mineralization process could be described by the Lifshitz–Slyozov–Wagner theory for Ostwald ripening. The demonstrated TiO2/CNC nanocomposite system exhibited excellent performance in dye degradation and antibacterial activity, suitable for a wide range of environmental remediation applications.