Experimental study and modeling of the photocatalytic oxidation of NO in indoor conditions

Heterogeneous photocatalytic oxidation (PCO) has shown to be a promising air purifying technology. Nitrogen monoxide (NO) is one common indoor air pollutant. The present paper addresses the PCO reaction in indoor conditions using NO as target pollutant with the gypsum plasterboard as a special substrate and carbon-doped TiO2 as photocatalyst. A photocatalytic reaction setup is introduced for the assessment of the indoor air quality. The PCO effect of the carbon-doped TiO2 is evaluated using different light wavelengths. Furthermore, the influence of the reactor volume on the PCO rate is studied. The Langmuir-Hinshelwood model is applied to describe the photocatalytic reaction mechanism. Experimental results show the validity of the L-H model in the present research. Using this model, a mathematical expression is proposed to describe the concentration change in the reactor

Heterogeneous Photocatalysis Applied to Concrete Pavement for Air Remediation

In the present work the degradation of nitrogen oxides (NOx) by concrete paving stones containing TiO2 to be applied in road construction is studied. A kinetic model is proposed to describe the photocatalytic reaction of nitric oxide (NO) in a standard flow laminar photoreactor irradiated with UV lamps. In addition the influence of several parameters that can affect the performance of these stones under outdoor conditions are investigated, such as irradiance, relative humidity and wind speed. The kinetic parameters present in the NO reaction rate are estimated employing experimental data obtained in the photoreactor. The obtained model predictions employing the determined kinetic constants are in good agreement with the experimental results of NO concentration at the reactor outlet