Diagnosis Of Reverse Vortex Gliding Arc Discharge And Its Application In TiO₂ Powder Synthesis

With the high energy density, electron density and high level of non-equilibrium, gliding arc discharge has a promising prospect in many industrial applications such as volatile organic pollutants treatment, effluent treatment, fuel reforming and material synthesis. Firstly, diagnosis of the discharge using alternating current power supply was performed. Then, the discharge was applied to synthesize TiO2 and Mn-doped TiO2 powder.1. The discharge voltage and current and emission spectra were applied to investigate the discharge process and the influence of discharge power, frequency, flow rate, electrode distance and structure on the discharge were investigated respectively. Within investigated range the results are as follows.The discharge voltage and current show the "arc-ignition", "arc-gliding" and "arc-extinction" stages of the discharge, respectively. The capacitance of the reactor calculated from the discharge voltage and displacement current is about 3.6 pF. The breakdown voltage reduces with the increase of discharge power and frequency respectively and rises while the electrode distance increases and the flow rate increases respectively. The quenching time in every discharge period increases with the increase of frequency, electrode distance and flow rate respectively.The results of emission spectra show that gas temperature rises with the increase of discharge power and frequency, respectively. The gas temperature is different when different ground electrodes were applied while other conditions were the same.2. In this experiment, reverse vortex gliding arc discharge was applied to synthesize TiO2 powder. Tetraisopropoxide (TTIP) was titanium source and air was oxygen source and discharge gas. The influence of discharge conditions was investigated. Within investigated range the results are as follows:the content of anatase increases as the discharge power increases. Frequency and electrode structure influence the powder’s phase content.Finally, manganese acetate was as manganese source to synthesize Mn-doped TiO2 powder in one-step procedure with AC reverse vortex gliding arc discharge for the first time. Within investigated range the results are as follows:When the Mn-doping level is 0.5%, the samples synthesized with different discharge power also show that the content of anatase increases as the discharge power increases. Anatase will decrease with the increase of incorporated Mn. The band gap is narrowed by the increasing incorporated Mn with obvious absorbance of visible light.