Studying the effects of processing parameters in the aerosol-assisted chemical vapour deposition of TiO2 coatings on glass for applications in photocatalytic NOx remediation
Yanda Wong, Yuankai Li, Lin Zhipeng, Andreas Kafizas
Abstract
Herein, we employ an aerosol-assisted method (AA-CVD) to produce TiO2 on window glass and study how the process parameters affect their photocatalytic activity towards NOx (NO + NO2) remediation. A range of process parameters are explored to produce 50 unique TiO2 coatings with wide ranging physicochemical properties. The physicochemical properties were examined using X-ray diffraction (XRD), atomic force microscopy (AFM), UV–visible transmission spectroscopy and transient absorption spectroscopy (TAS), and the photocatalytic activity towards NO gas was measured using protocol akin to the ISO (22197-1:2016). The most active sample showed an NO removal of ∼14.4 ± 1.7 % and NOx removal of ∼5.4 ± 0.77 %, which was ∼40 and ∼25 times higher than that of a commercially available self-cleaning window. The links between the process parameters, physicochemical properties and photocatalytic activity were studied in depth, where it was seen that the three most influential physicochemical properties on the observed activity were surface roughness, charge carrier population and charge carrier lifetime. Therefore, we recommend that these properties be targeted in the rational design of more active coatings for applications in photocatalytic NOx remediation.