Surface Prechlorination of Anatase TiO2 for Enhanced Photocatalytic Oxidation of Toluene and Hexane

Abstract

Dedicated to Professor Andre¬ M. Braun on the occasion of his 60th birthday We report the influence of prechlorination of TiO 2 powder on the activity for the photocatalyzed oxidation of hydrocarbons (toluene, hexane) and oxygenates (acetone, butan-1-ol). Water-and HCl-pretreated catalyst are prepared by impregnation of TiO 2 powder in H 2 O and in HCl solutions, respectively, followed by drying at room temperature. X-Ray photoelectron spectroscopy (XPS) analysis demonstrates the surface prechlorination efficiency: 1 g of TiO 2 impregnated with 3 ml of 3n HCl solution results in a chlorine surface concentration of 1.6%. Prechlorination results in a photo-oxidation-rate enhancement for toluene and hexane, no change for butan-1-ol, and inhibition for acetone. This pattern is the same as that demonstrated earlier by us when these reactants are co-fed with the chlorine source trichloroethylene (TCE).

Boosting Photocatalytic Performance of Inactive Rutile TiO2 Nanorods under Solar Light Irradiation: Synergistic Effect of Acid Treatment and Metal Oxide Co-catalysts

“…FT-IR spectra of the as-prepared TO-NR and ATO-NR are shown in Figure A. The broad peaks at 3100–3600 cm –1 and a peak at 1634 cm –1 corresponded to stretching vibration of O–H and bending vibration of surface H 2 O, respectively. , As shown in Figure A, the intensity of the peaks of surface hydroxyl groups and surface adsorbed H 2 O was increased with acid concentration (up to 1.0 M) and then decreased at higher concentration of HCl (2.0 M) as shown in Figure A (d) . This decrement is due to that most of the surface sodium ions were removed and the concentration of alkaline chlorine (Cl – ) was increased over the surface of NR.…”

A surface science perspective on TiO2 photocatalysis

“…There are inconclusive results on the effect of surface Cl on photooxidation reactions, exhibiting either an inhibiting influence on surface photooxidation reactions or no influence at all [1296,1302,1472,[1493][1494][1495]. d'Hennezel and Ollis [1494] have shown that surface chlorination enhanced the overall photooxidation of toluene and hexane, had no effect on 1-butanol, and inhibited acetone photooxidation. This diverse behavior points to selective effects by adsorbed Cl − on specific reactants and intermediates.…”

Well Dispersive TiO2 Nanoparticles as Additives for Improving the Tribological Performance of Polyalphaolefin Gel Lubricant

“…TiO 2 possesses photocatalysis in organic media under UV irradiation, which could produce intermediates including ketone, alcohol, aldehyde, and organic acid. , Figure shows the friction coefficients of PAO10–1% MOB–0.5% TTO and PAO10 under the different UV irradiation time. The mean friction coefficients of PAO10 have little change with different irradiation times.…”