Papers by Author: Chien Chih Chen

Abstract: This study employs a direct-synthesis method to produce titania (TiO2)/water nanofluid, which is a working fluid involved in the electrophoretic deposition (EPD) of nanophotocatalytic films. In general, using organic solvents and water as the bulk liquids in EPD produces environmental pollution and defective films due to the electrolysis of water. To mitigate water electrolysis, the fabrication method proposed in this study adds an anionic dispersant to the TiO2/water nanofluid. The anionic dispersant changes the surface charge of TiO2 nanoparticles to facilitate their deposition on the anode. For low voltage EPD processes, this method effectively improves defective nanophotocatalytic films. These defects are caused by bubbles from the water electrolysis, as the volume of oxygen produced at the anode amounts to half of the hydrogen produced at the cathode. The objective of this study is to propose empirical equations describing the relationship between film thickness and electric parameters.

Abstract: This study develops a measurement method for testing the efficiency of photocatalysts in the degradation of NH3 gaseous concentrations. The catalysts used in this study are the same as those used previously in our UV/VIS spectrophotometer. Reaction measurements were carried out at 27°C and 17°C under ambient pressure on Heat Ventilating and Air Conditioning (HVAC) system. Quartz plates were coated with TiO2 nanocatalyst. Then the plate was put in the stable reaction cell under different flow rates of circulation. The experiment gives a direct and simple measurement of ammonia flux and hence of overall ammonia emission rate. The results reveal that the Submerged Arc Nanoparticle Synthesis System (SANSS) TiO2 nanocatalyst has excellent degradation efficiency towards NH3, so that when it is exposed to UV irradiation for 60 minutes, the gaseous concentration can be reduced to 10% of the original concentration. In addition, the rate constant of the degradation reaction of the self-made TiO2 nanocatalyst towards NH3 is as high as 0.039min-1.

Abstract: This research carries out an inexpensive, rapid and novel exercise, which is applied to perform the photocatalyst decomposition effectiveness of Methanol and Ethanol in gaseous form. The major devices of this applicable measurement developed by this practice are only utilizing ultraviolet-visible spectrophotometer and quartz cuvette, and the experimental procedures are straightforward and speedy. In the conduct experiments, Methanol and Ethanol with a specific concentration is initially injected into an enclosed quartz cuvette. Then the cuvette is put in ultraviolet- visible spectrophotometer to measure the Methanol and Ethanol concentration, so as to obtain an unique UV absorbance spectrum at its particular concentration. In the conduct experiments of measuring photocatalyst decomposition efficiency, the self-made (SANSS) nanocatalyst TiO2 is initially coated in the quartz plate, and put into the quartz. Then a specific concentration of methanol alcohol and ethanol is injected into the quartz cuvette under the UV irradiation exposure, so as to carry out photodecomposition of Methanol and Ethanol experiment. After that, the cuvettes are then put into the ultraviolet-visible spectrophotometer for measuring the absorbance intensity of UV spectrums in order to produce degradation chart. The preliminary results point out that the self-made nanocatalyst TiO2 has exceptionally outstanding decomposition efficiency which further points out the fact that, when UV irradiation for 60minutes, the gaseous Methanol can be reduced to 3.8% of the original sample, and the gaseous Ethanol can be reduced to 6% of the original sample. But when exercising with commercial nanocatalyst TiO2 to undergo the same process exactly under the same circumstances, the residue gaseous concentration can only be reduced to 17% and 16% of the gaseous Methanol and Ethanol original sample.