Abstract: Mesoporous nanosize TiO₂ spheres (SP-TiO₂) were prepared using natural polymer nanocrystalline cellulose (NCC) as template. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction, ultraviolet-visible diffuse reflection spectroscopy, and N₂ adsorption-desorption were used for the characterization of the SP-TiO₂ photocatalyst. The results showed that SP-TiO₂ was uniform in size with a diameter of 100–200 nm. SP-TiO₂ was composed of smaller crystal particles (10–20 nm). The average mesoporous pore diameter of SP-TiO₂ was 8.2–13.5 nm, which increased with increasing calcination temperature. A nano-scale reactor that was formed by bonding between the hydroxyl groups of NCC long-chain can inhibit the growth and aggregation of the TiO₂ precursor, promote its self-assembly into spherical structure, and inhibit the phase transformation from anatase to rutile. SP-TiO₂ prepared at 600 ºC exhibited the highest activity with the phenol degradation percentage of 89%.

Key words: sphere, mesopore, titania, nanocrystalline cellulose, template, hydrolysis