Effect of particle size and crystal structure of titanium dioxide nanoparticles on the photocatalytic properties

Titanium dioxide nanoparticles with different average diameter of particles (8, 18 and 27 nm) and different crystal structure (anatase and rutile) were used for degradation of C.I. Acid Red 88 (AR88) as a model compound. The degree of degradation of AR88 by TiOz nanoparticles under irradiation of UV-light (254 nm) decreases with reducing Ti02 nanoparticles from 27 to 8 nm in anatase crystal structure. Ti02-P25 anatase and rutile (80:20) showed high photoactivity than other samples TiOz- UVI 00 (8 nm diameter and 100% anatase) and Ti02-Merck (27 nm diameter and 95% anatase).