Comparison of the Adsorption–Desorption Kinetics of Limonene and Carvone on TiO₂ and SiO₂ Surfaces under Different Relative Humidity Conditions

Adsorption and desorption of volatile organic compounds (VOCs) on indoor material surfaces can impact VOC concentrations in air. In this study, we investigate the adsorption kinetics limonene one its oxidation products, carvone, at 297 ± 1 K using situ Fourier transform infrared (FTIR) spectroscopy. particular, carvone two model indoor-relevant surfaces, TiO2 (a component paint self-cleaning surfaces) SiO2 for window glass), are compared low relative humidity as well higher humidity. Carvone readily partitions to both with slower limonene. Under dry conditions, is about 40 times faster than that from TiO2, four SiO2, respectively. high presence adsorbed water generally increases yet has no effect carvone. The K2-SURF been previously applied adsorption/desorption here, it used obtain a detailed mechanism interactions function explain observed kinetics. Importantly, combined experimental results kinetic modeling classical ab initio molecular dynamics simulations provide mechanistic insights into heterogeneous implications air quality.