title: Microwave-enhanced catalytic degradation of 4-chlorophenol over nickel oxides under low temperature.
abstract: Microwave-enhance catalytic degradation (MECD) of 4-chlorophenol (4-CP) using nickel oxide was studied. A mix-valenced nickel oxide was obtained from nickel nitrate aqueous solution through a precipitation with sodium hydroxide and an oxidation by sodium hypochlorite (assigned as PO). Then, the as-prepared PO was irradiated under microwave irradiation to fabricate a high active mix-valenced nickel oxide (assigned as POM). Further, pure nanosized nickel oxide was obtained from the POM by calcination at 300, 400 and 500 degrees C (labeled as C300, C400 and C500, respectively). They were characterized by X-ray (XRD), infrared spectroscopy (IR) and temperature-programmed reduction (TPR). Their catalytic activities towards the degradation of 4-CP on the efficiency of the degradation were further investigated under continuous bubbling of air through the liquid-phase and quantitative evaluation by high pressure liquid chromatography (HPLC). Also, the effects of temperature, pH and kinds of catalysts on the efficiency of the degradation have been investigated. The results showed that the 4-CP was degraded completely by MECD method within 20 min under pH 7, T=40 degrees C and C=200 g dm(-3) over POM catalyst. The relative activity was affected significantly with the oxidation state of nickel.
authors.affiliation: Department of Applied Chemistry and Materials Science, Chung Cheng Institute of Technology, National Defense University, Tahsi, Taoyuan, Taiwan, ROC.
authors.forename: Teh-Long
authors.initials: TL
authors.lastname: Lai
authors.forename: Jyong-Yue
authors.initials: JY
authors.lastname: Liu
authors.forename: Kim-Fui
authors.initials: KF
authors.lastname: Yong
authors.forename: Youn-Yuen
authors.initials: YY
authors.lastname: Shu
authors.forename: Chen-Bin
authors.initials: CB
authors.lastname: Wang
mesh_terms: D002384:Catalysis; D002733:Chlorophenols / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008872:Microwaves; D009532:Nickel / Q000737:chemistry*; D010316:Particle Size; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D002733:Chlorophenols; D014874:Water Pollutants, Chemical; C029107:4-chlorophenol; D009532:Nickel; C028007:nickel monoxide