Investigation of the photolysis of the surface-adsorbed HNO3 by combining laser photolysis with Brewster angle cavity ring-down spectroscopy

We have investigated the photolysis of HNO3 adsorbed on fused silica surfaces by using excimer laser photolysis at 308 and 351 nm combined with direct probing excited NO2 product retained on surfaces using Brewster angle cavity ring-down spectroscopy. The sensitivity and the capability of this technique in the study of surface photochemical processes have been demonstrated. The quantum yields of the excited NO2 produced from the HNO3 photolysis on surfaces are (1.1 ± 0.2) and (1.0 ± 0.3) at 308 and 351 nm. The disappearance rate of excited NO2 in the presence of H2O vapor was measured to be (2.9 ± 0.8) × 10−13 cm3 molecule−1 s−1 at 295 K.