Degradation of Rhodamine B and Bisphenol A using Potassium peroxymonosulfate activated by one-step prepared sulfur-doped carbon nitride as a non-metallic heterogeneous photocatalyst

• Main Authors: Zhi-Yu Zhang, 張志宇
• Other Authors: 林坤儀
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/10473021732817643742

碩士 === 國立中興大學 === 環境工程學系所 === 105 === Advanced Oxidation Processes (AOPs) mainly removes contaminants by free radical oxidation which is produced from oxidants. In this study, Potassium peroxymonosulfate (PMS) was used as the oxidant to produce sulfate radicals (SO4-•) which had stronger redox potential than hydroxyl radical (OH•). However, it shows slow response for PMS producing sulfate radicals. A transition metal catalyst to enhance activate degradation speed is needed. In order to reduce the cost and environmental impact of the metal catalyst, non-metallic catalysts will be seen as a future trend. In this work, one-step preperation for sulfur-doped carbon nitride (CNS) was used as a non-metallic and easily prepared catalyst to activate PMS to degrade target contaminants Rhodamine B (RhB) and Bisphenol A (BPA). CNS was analyzed by FE-SEM, TEM, BET, XRD, XPS and other instruments. Since the prepared CNS exhibits a higher surface area and catalytic activity than the undoped sulfur-based carbonitride (CN). Contaminants degradation by CNS activated PMS exhibits a much higher efficiency than CN activated PMS. Therefore we speculate that the synergistic effect of sulfur and nitrogen co-doping in CNS may lead CNS exhibit higher catalytic and photocatalytic properties. From RhB and BPA degradation test, temperature, pH, co-existing ion simulation of the target contaminants may occur in the environment. It is more conducive for CNS catalyzed PMS to degrade contaminants in high temperature and neutral conditions. When high concentrated NaCl as co-existing ions was added into contaminated water, the effect of CNS catalyzed PMS degradation was not affected. The free radical scavenger test proved that sulfate radicals are the main free radicals in this experiment. Finally, five times CNS recyclability recveals almost the same result to CNS catalyzed PMS degradation batch experiment. These characteristics indicate that CNS is a convenient preparation and effective nonmetallic photocatalyst and is suitable for catalyzing PMS degradation of RhB and BPA.