Proceedings of nanoGe Fall Meeting19 (NFM19)
Publication date: 18th July 2019
Atmospheric pollution has been recognized as one of the major threats for modern society. Among the various manmade air pollutants, nitrogen oxides (NOx) induce the ozone production in troposphere and cause acid rains. In addition, NOx, especially nitric oxide (NO) and nitrogen dioxide (NO2) severely affect respiratory and immune systems [1]. Titanium dioxide (TiO2) is the most widely used semiconductor for the photocatalytic decomposition of gaseous and liquid-phase pollutants. Despite its favorable properties like chemical inertness, long-term stability and low cost, TiO2 has a band gap of 3.2 eV. This large band gap enables the harvesting of UV light only, which accounts for 4-5% of incoming solar energy[2] .There have been numerous attempts to extend the photocatalytic efficiency of TiO2 in the broader solar spectrum via nonmetal doping, metal doping, and surface modifications with polymers.
In this study, oleic acid capped CdSe/CdSeTe nanoplatelets (NPLs) were synthesized for the surface functionalization of TiO2. Structural characterizations were carried out by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) , ATR-Fourier-transform infrared spectroscopy, transmission electron microscopy (TEM) to confirm the formation of desired materials. These NPLs/TiO2 composites were then tested in NO photo-oxidation under UVA and visible light, showing a remarkable activity in NOx abatement and a high selectivity for nitrate species as compared to standard benchmark TiO2 photocatalyst. The improved photocatalytic property can be attributed to decrease in bandgap and enhanced photogenerated electron-hole pair separation as a result of incorporation of CdSe/CdSeTe NPLs to TiO2. The stability of composites was investigated by extension of reaction duration. Even though some decrease in photocatalytic activity and selectivity of NPLs/TiO2 composites observed, but their performance was even significantly better than pure TiO2. This facile synthesis approach in combination with a high performance present a valuable material for next generation technologies for the abatement of harmful gaseous pollutants.