Hg-0(g) is known to undergo photo-catalytic oxidation by UVA-irradiated TiO2 surfaces. One micrometre layers of TiO2 on quartz glass were irradiated within the 240-800 nm range. Gaseous mercury was measured by mass spectrometry single ion monitoring. The surface configuration and elemental characterization of TiO2 layer was evaluated using scanning electron microcopy with energy dispersive spectroscopy. The LH adsorption constant of was found to be K-Hg = (5.1 +/- 2.4) x 10 (14) cm(3) and an apparent surface deposition rate of k = (7.4 +/- 2.5) x 10(14) min (1) cm (2) under experimental conditions. Water did not affect the rate constant. We show TiO2 could be employed to reduce mercury concentrations in gas streams, even at very high Hg-0 concentrations. (C) 2010 Elsevier B.V. All rights reserved.