The nanometer and ordinary anatase titanium dioxide(TiO_2) powders were adopted as the sonocatalysts for the degradation of methyl orange used as a model compound for the first time. It was found that the sonocatalytic degradation effect of methyl orange in the presence of TiO_2 powder were much better than that without TiO_2, but the sonocatalytic activity of the nanometer anatase TiO_2 particle was obviously higher than that of ordinary anatase TiO_2 particle. Although there are many factors influencing sonocatalytic degradation of methyl orange, the experimental results showed that the best degradation ratio of methyl orange could be obtained when the experimental conditions were: initial concentration 15 mg/L, nanometer anatase TiO_2 adding amount 750 mg/L, ultrasonic frequency 40 kHz, output power 50 W, pH = 3.0 and temperature 40℃ within 150 min. In addition, the catalytic activity of reused nanometer anatase TiO_2 catalyst was also studied and found to decline gradually comparing with initial nanometer anatase TiO_2 catalyst. All experiments indicated that the method of the sonocatalytic degradation of organic pollutants in the presence of TiO_2 powder was an advisable choice for non- or low-transparent organic wastewaters.
The mixed crystal nanometer TiO2 sonocatalyst was prepared by ultrasonic irradiation in hydrogen peroxide solution. The sonocatalytic activities were validated through the degradation of acid red B solution by ultrasonic irradiation in the presence of the title TiO2 catalyst. The results show that the sonocatalytic activity of the title TiO2 catalyst is obviously higher than that of original rutile and anatase nanometer TiO2 catalysts. The degradation ratio of acid red B in the presence of the title TiO2 catalyst surpasses 75%, while the degradation ratios are only 54.62% and 35.24% for rutile and anatase nanometer TiO2 catalysts, respectively.
The crystal and molecular structures of the Na[Eu Ⅲ (edta) ( H2 O) 3] · 4H2O ( edta = ethylenediaminetetraacetic acid) and Na4[Eu2Ⅲ (Httha)2] · 10H2 O ( ttha = triethylenetetraminehexaacetic acid) complexes were determined by single-crystal X-ray structure analyses.The crystal of Na[ EuⅢ (edta) (H2O)3] · 4H2O belongs to orthorhombic crystal system and Fdd2 space group.The crystal data are as follows: a = 1.9415 (15)nm, b = 3.544(3 )nm, c = 1.203(9)nm, V = 8.327(5)nm3, Z = 16, M = 589.27, Dc= 1.880 g· cm-3, μ= 3.108mm-1 and F(000) = 4704.The final R and wR values are 0.0312 and 0.0750 for 2091[I ＞ 2.0σ (I)] reflections, and 0.0344and 0.0766 for all 3932 unique reflections, respectively.The[EuⅢ (edta) (H2O) 3] - anion has a nine-coordinate pseudo-monocapped square antiprismatic structure in which the nine coordinate atoms, two N and seven O, are from one edta ligand and three water molecules.The crystal of Na4[Eu2Ⅲ (Httha)2] · 10H2O belongs to orthorhombic system and Pccn space group.The crystal data are as follows: a = 2.610(3)nm, b = 2.089(3)nm, c = 2.239(3)nm, V =12.208 ( 28 ) nm3, Z = 8, M = 1548.92, Dc= 1.686g·cm-3,μ = 2.115 mm-1andF(000) = 6272.Thefinal R and wR are 0.0625 and 0.1091 for 9834[I ＞ 2.0σ(I)] reflections, and 0.1608 and 0.1471 for all 37818 unique reflections, respectively.The whole complex molecule is composed of two close parts in which each one has a nine-coordinate structure with distorted monocapped square antiprismatic prism.The ttha ligand in the[Eu2Ⅲ (Httha)2] 4- anion coordinates to one Eu Ⅲ ion with three N atoms and four O atoms and to the other Eu Ⅲ ion with two O atoms.
Wang Jun Wang Yu Liu Xinzhu Liu Zhenrong Zhang Zhaohong Tong Jian
Various affecting factors and degradation mechanism were studied on ultrasonic degradation of methyl orange adopting Y2O3 doping anatase TiO2 catalyst prepared in laboratory.In the experiment, the UV-VIS spectrophotometer was used to follow and inspect the degradation process of methyl orange.The results indicate that the ultrasonic degradation ratios of methyl orange in the presence of anatase TiO2 catalyst are much better than those without catalyst.Moreover, the catalytic performance of Y2O3 doping anatase TiO2 catalyst is obviously higher than that of anatase TiO2 catalyst without doping.The optimal conditions were adopted in this work and the degradation and COD elimination ratio of methyl orange got to98% and 99.0% in 90 min, respectively.
Wang Jun Guo Baodong Pan Zhijun Liu Zhenrong Wen Fuyu Zhang Zhaohong
