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