Adsorption and Reactions of CHCl₃on Powdered TiO₂

Abstract

The adsorption and reactions of CHCl3 on three commercially available TiO2 powders have been investigated by Fourier transform infrared spectroscopy in a gas‐solid reaction system. Probably, owing to the difference in surface morphology, CHCl3 is weakly adsorbed on two of the three TiO2 samples at 35 °C. But, as the more reactive TiO2 is exposed to CHCl3 at 35 °C, the surface is found to be covered with CHCl3, HCOO, H2O, and CO. In addition to these surface species, gaseous HCl and CO are generated at higher temperatures. Photoirradiation of CHCl3 on TiO2 in the absence or presence of O2 causes the decomposition of CHCl3. This photoprocess is enhanced in O2.

Nanoscale Investigation of Photoinduced Hydrophilicity Variations in Anatase and Rutile Nanopowders

“…Commercial TiO 2 nanosized powders with two different structures are studied: pure anatase (99.8% pure titanium(IV) oxide from Aldrich Chemical Co.) and pure rutile (99.995% pure titanium(IV) oxide from Aldrich Chemical Co.). BET area and particle size of approximately 10.9 m 2 /g and 48 nm, respectively, for anatase, and 2.5 m 2 /g and 240 nm, respectively, for rutile, were reported in previous studies. , …”

“…BET area and particle size of approximately 10.9 m 2 /g and 48 nm, respectively, for anatase, and 2.5 m 2 /g and 240 nm, respectively, for rutile, were reported in previous studies. 36,37 Powders are dispersed in distilled water by sonication at 40 °C for 1 h (10 −2 mol/L powder concentration); then, a drop of suspension is deposited on a glass slide previously cleansed with ethanol, and dried on a hot plate at 40 °C.…”