In-situ observation of photocatalysis of gaseous trichloroethylene using a fourier transform infrared in the presence of a visible light responding homemade oxynitride doped TiO2 under blue LED and violet LED irradiations

A visible light responding TiO2 photocatalyst was prepared by the hydrolysis of TiCl4 with ammonia. Its structures were characterized to anatase with doping of oxynitride by XRD and XPS followed by drying and heat treatment at 400 °C for 2 h (TiON400). The primary particle size observed by TEM was ~10 nm, and the BET surface area was 320 m2/g. Photocatalytic degradation of trichloroethylene (TCE) over TiON400 under blue light emitting diode (BLED) and violet light emitting diode (VLED) irradiation was tested using a Fourier transform infrared (FTIR) spectrometer. The collected FTIR spectra verified the decrease in TCE concentration and the formation of intermediates such as dichloroacetyl chloride (DCAC) and COCl2 during the photocatalysis of TCE. It is concluded that in-situ FTIR analysis can be a useful and reliable tool to evaluate the photocatalytic performance of materials. A new ISO standard for photocatalysis testing method with FTIR analysis under ultraviolet, visible, or violet irradiation is possible to propose.