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1.
2,9,16,23-四-芳氧基酞菁镍的合成及光谱性质 总被引:2,自引:0,他引:2
用4-苯氧基邻苯二腈、4-(4-羟基-苯氧基)邻苯二腈、4-(β-萘氧基)邻苯二腈和无取代邻苯二腈分别和金属盐、尿素、钼酸铵在熔融状态下合成2,9,16,23-四-苯氧基金属酞菁、2,9,16,23-四-(4-羟基-苯氧基)金属酞菁和2,9,16,23-四-(β-萘氧基)金属酞菁以及无取代金属酞菁,对产物进行了IR、UV-vis光谱测定和表征,并对比3种化合物谱学性质.实验结果表明,对于芳氧基取代的金属酞菁来说,随着苯环数目和苯环上供电子基数目的增加,取代酞菁产生的红移程度都会变大. 相似文献
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先期通过钛酸丁酯、邻苯二腈(磺基邻苯二腈),以Co(Ⅱ)为模板,经溶胶—凝胶过程及300℃,烧结,在纳米颗粒表面直接原位合成CoPc/TiO_2、CoTSPc/TiO_2复合材料(Co:Ti= 1%摩尔分数),通过XRD、Zeta电位、UV-Vis、FTIR、荧光光谱等对材料进行了表征。结果表明,经原位合成后酞菁/TiO_2,由于存在CoPc,CoTSPc与TiO_2表面O~(2-)轴向配位以及后者磺基所形成的双齿螯合,加速光生电荷与能量转移效率,提高了可见光光催化效率,实现在低功率可见光下,就具有明显的光催化效果,有一定的应用前景。 相似文献
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光催化技术是一种新兴的高效节能污水处理技术,而纳米TiO2光催化技术可以降解污水中的有机物,在废水有机物处理中有广阔的应用前景。本文就介绍实现纳米TiO2固载化的各种物理方法,讨论玻璃、硅胶以及金属等不同载体对纳米TiO2光催化活性的影响。 相似文献
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运用醇热法制备介孔二氧化钛(m-TiO_2),并借助光还原法制备m-TiO_2载银(m-TiO_2/Ag)复合材料,通过透射电镜和X射线衍射等手段对复合材料的形貌和组成进行表征,并以亚甲基蓝(MB)的脱色降解来表征不同Ag含量样品的光催化性能,通过生长曲线、最小抑菌浓度和抑菌环对其抗菌性能进行表征。结果表明:用醇热法制备的m-TiO_2是以锐钛矿为主含有少量板钛矿的混晶,金属Ag颗粒沉积在m-TiO_2表面;纳米银负载可显著提高mTiO_2的可见光光催化性能;亚甲基蓝的光催化降解反应遵循一级反应动力学模型;m-TiO_2/Ag复合材料的抗菌性能随着载银量的增加而逐渐提高。 相似文献
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Luan J Zhao W Feng J Cai H Zheng Z Pan B Wu X Zou Z Li Y 《Journal of hazardous materials》2009,164(2-3):781-789
Bi(2)AlVO(7) was prepared by solid-state reaction technique for the first time and the structural and photocatalytic properties of Bi(2)AlVO(7) and Bi(2)InTaO(7) were investigated. The results showed that Bi(2)AlVO(7) crystallized in the tetragonal crystal system with space group I4/mmm. In addition, the band gaps of Bi(2)AlVO(7) and Bi(2)InTaO(7) were estimated to be about 2.06 and 2.81 eV. The photocatalytic degradation of aqueous methylene blue (MB) dye with Bi(2)AlVO(7) or Bi(2)InTaO(7) as catalyst was investigated under visible light irradiation. Bi(2)AlVO(7) showed higher photocatalytic activity compared with Bi(2)InTaO(7) for photocatalytic degradation of MB under visible light irradiation. Complete removal of aqueous MB dye was realized after visible light irradiation for 160 min with Bi(2)AlVO(7) as the photocatalyst. The reduction of the total organic carbon (TOC) and the formation of inorganic products, SO(4)(2-) and NO(3)(-) revealed the continuous mineralization of aqueous MB dye during the photocatalytic process. The possible photocatalytic degradation pathway of aqueous MB dye was revealed under visible light irradiation. 相似文献
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《Materials and Manufacturing Processes》2007,22(3):314-317
Natural zeolites were characterized in order to be studied as surface reaction for phthalocyanine synthesis. Nonsubstituted phthalocyanines have been synthesized starting from phthalonitrile in various nonaqueous solvents in the presence of two different zeolites of the clinoptilolite type. The zeolites are shown to be effective matrices for phthalonitrile cyclisation at relatively low temperatures (0-40°C). The presence of CaCO3 in one of two natural mineral of zeolites suggested a low activity of the surface to promote the cyclization of phthalonitrile at low temperature. The influence of different solvents is not relevant for the heterogeneous reaction. 相似文献
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以TiCl4 、Fe (NO3 )3·9H2O 和Na2SiO319H2O 为原料, 采用溶胶凝胶法结合超临界流体干燥法(SCFD)制备了纳米级TiO2/ Fe2O3 和TiO2/ Fe2O3/ SiO2 复合光催化剂。以光催化降解苯酚对所得催化剂的催化活性进行了评价。结果表明, 纳米TiO2/ Fe2O3 复合粒子与单组分TiO2 比较, 复合粒子光催化活性高于单组分的TiO2, 6h 苯酚降解率高达95.9 %。SiO2 的加入可以抑制纳米粒子粒径的长大和晶相的转变, 增强TiO2 纳米粒子的热稳定性。复合光催化剂中Fe2O3 最佳掺入量为0.06 %, SiO2 最佳掺入量为10 %(摩尔分数) 。并用XRD、TEM 和FTIR 等手段进行了表征。TiO2 以锐钛矿型形式存在, SiO2 以无定性形式存在。比较了不同制备方法制得的TiO2/ Fe2O3 复合光催化剂, 得出超临界干燥法制备的光催化剂具有粒径小、比表面积大、分散性好、光催化活性高等特点。采用超临界流体干燥可直接得锐钛型纳米复合光催化剂。 相似文献
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Preparation and characterization of SiO2-pillared H2Ti4O9 and its photocatalytic activity for methylene blue degradation 总被引:1,自引:0,他引:1
SiO(2) pillared layered titanate (SiO(2)-H(2)Ti(4)O(9)) was prepared via intercalating organosilanes into the interlayers of the layered K(2)Ti(4)O(9) followed by calcination at 500 degrees C. The resulting materials were characterized using XRD, N(2) adsorption-desorption isotherms, UV-vis spectra, IR spectroscopy and Raman spectroscopy. The photocatalytic activity of SiO(2)-H(2)Ti(4)O(9) was evaluated by photocatalytic degradation of aqueous methylene blue dye (MB). XRD and specific surface area results showed that SiO(2)-H(2)Ti(4)O(9) had an interlayer distance of 1.45 nm and a specific surface area of 148 m(2)g(-1). UV-vis absorption spectrum of SiO(2)-H(2)Ti(4)O(9) showed a red shift, indicative of a narrower band gap compared to K(2)Ti(4)O(9). In addition, SiO(2)-H(2)Ti(4)O(9) showed higher MB adsorption capacity compared to H(2)Ti(4)O(9) and K(2)Ti(4)O(9). MB photodegradation over H(2)Ti(4)O(9), K(2)Ti(4)O(9) and SiO(2)-K(2)Ti(4)O(9) followed zero-order kinetics under our experimental conditions, and the photocatalytic activity of SiO(2)-H(2)Ti(4)O(9) was found to be three times higher than that of K(2)Ti(4)O(9), which could be attributed to the increase of interlayer space and specific surface area of SiO(2)-pillared layered titanate. 相似文献
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Nanoglued binary titania (TiO2)-silica (SiO2) aerogel, as a novel type of photocatalyst, has been synthesized on glass substrates. Using an about-to-gel SiO2 sol as nanoglue, anatase TiO2 aerogel was immobilized into a three-dimensional mesoporous network of the SiO2. Factorial designs were employed to optimize both TiO2 aerogel and binary TiO2-SiO2 aerogel synthesis. Characterization of the as-prepared TiO2 and binary samples by surface area, porosity, and surface chemical composition showed that the photocatalysts were high-surface-area nanoporous materials, with a Ti4+ valency. The binary aerogel exhibited high photocatalytic activity for the degradation of methylene blue (MB) under simulated solar light; the reaction followed the pseudo first-order Langmuir-Hinshelwood (L-H) kinetic model. Fluorescence spectroscopy revealed that the hydroxyl (*OH) radical was formed during the illumination of the binary TiO2-SiO2 aerogel in a solution of probe molecules, which corroborates the probable mechanism of hydroxyl radical oxidation of contaminants in photocatalytic reactions. 相似文献
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Photocatalytic activity of TiO2 doped with boron and vanadium 总被引:2,自引:0,他引:2
Bettinelli M Dallacasa V Falcomer D Fornasiero P Gombac V Montini T Romanò L Speghini A 《Journal of hazardous materials》2007,146(3):529-534
Boron (B)- and vanadium (V)-doped TiO(2) photocatalysts were synthesized using modified sol-gel reaction processes and characterized by X-ray diffraction (XRD), Raman spectroscopy and N(2) physisorption (BET). The photocatalytic activities were evaluated by monitoring the degradation of methylene blue (MB). The results showed that the materials possess high surface area. The addition of B favored the transformation of anatase to rutile, while in the presence of V, anatase was the only phase detected. The MB degradation on V-doped TiO(2) was significantly affected by the preparation method. In fact while the presence of V in the bulk did not influence strongly the photoreactivity under visible irradiation, an increase of surface V doping lead to improved photodegradation of MB. The degradation of MB dye indicated that the photocatalytic activities of TiO(2) increased as the boron doping increased, with high conversion efficiency for 9mol% B doping. 相似文献
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Jing-Fei Luan Xi-Ping Hao Shou-Rong Zheng Guo-You Luan Xiao-Shan Wu 《Journal of Materials Science》2006,41(23):8001-8012
Bi2MTaO7 (M = Y and La) were synthesized by solid-state reaction method and their structural and photocatalytic properties were investigated. The results indicated that these compounds crystallize in the pyrochlore-type structure, cubic system with space group Fd-3 m. In addition, the band gaps of Bi2LaTaO7 and Bi2YTaO7 were estimated to be about 2.17(3) and 2.22(7) eV, respectively. For the photocatalytic water splitting reaction, H2 or O2 evolution was observed from pure water respectively with Bi2MTaO7 (M = Y and La) as the photocatalysts under ultraviolet light irradiation. Photocatalytic degradation of aqueous methylene blue (MB) dye over these compounds was further investigated under visible light irradiation. Bi2MTaO7 (M = Y and La) showed markedly higher catalytic activity compared to P-25 for MB photocatalytic degradation under visible light irradiation. Complete removal of aqueous MB was observed after visible light irradiation for 190 min with Bi2LaTaO7 as the photocatalyst and for 200 min with Bi2YTaO7 as the photocatalyst. The decrease of the total organic carbon (TOC) and the formation of inorganic products, SO42− and NO3−, demonstrated the continuous mineralization of aqueous MB during the photocatalytic process. 相似文献
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Benjaram M. Reddy Gunugunuri K. Reddy Komateedi N. Rao Ibram Ganesh Jose M. F. Ferreira 《Journal of Materials Science》2009,44(18):4874-4882
Titania–silica, titania–alumina, and titania–zirconia mixed oxides (1:1 molar ratio) were prepared by a microwave-induced
solution combustion synthesis technique. The prepared materials were characterized by thermogravimetry/differential thermal
analysis, X-ray diffraction (XRD), Raman spectroscopy, BET surface area, X-ray photoelectron spectroscopy (XPS), ultraviolet–visible
diffuse reflectance spectroscopic (UV–Vis DRS), and Fourier transform infrared (FTIR) techniques to assess their physicochemical
properties. Their photocatalytic activity for the degradation of phenol in aqueous solution under sunlight was studied. XRD
and Raman studies revealed the presence of titania in the form of anatase phase in all the mixed oxides synthesized. The XRD
studies further suggested that titania–zirconia contains an additional (Ti,Zr)O2 phase. UV–Vis DRS results reveal that all samples exhibit absorption maxima near visible region. FTIR results revealed the
presence of Ti–O–Si linkages in the titania–silica sample, which are responsible for its higher activity in the photocatalytic
degradation of phenol under sunlight. 相似文献
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分别采用溶剂热法和草酸盐法制得具有分级微/纳结构但形貌迥异的两种ZnO材料,以亚甲基蓝溶液(MB)作为目标降解物对其光催化性能进行评价。结果表明:溶剂热法所制得的ZnO呈花状微球形貌,由纳米片自组装而成;草酸盐法所制得的ZnO为微米棒状形貌,以纳米颗粒为基本单元发展而来。草酸盐法ZnO材料具有更为优异的光催化性能,其对亚甲基蓝溶液的降解反应速率常数是溶剂热法ZnO材料的7.65倍。活性自由基物种鉴定结果证实,两种ZnO材料在受到紫外光激发时均能产生·OH和·O2-活性自由基。两种ZnO样品光催化性能的差别源于能带结构不同所引起的活性自由基生成数量上的差异。较之溶剂热法ZnO,草酸盐法ZnO在受紫外光激发时产生的·OH和·O2-数量更多,且以强氧化能力的·OH为主,因而表现出更为优异的光催化性能。 相似文献
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为了改善氧化亚铜(Cu2O)的光催化性能,将Cu2O颗粒和聚乙烯醇(PVA)同时加入纳米纤维素(CNF)中,成功制备了具有三维(3D)多孔结构和丰富活性位点的功能化纤维素基气凝胶(Cu2O-PVA/CNF)。采用扫描电子显微镜、傅里叶变换红外光谱、X射线衍射仪、全自动比表面积、压缩测试对气凝胶样品进行了表征。以降解亚甲基蓝(MB)为模型污染物,评价了Cu2O-PVA/CNF复合催化剂的光催化性能,考察了6wt%Cu——2O-PVA/CNF在不同初始浓度、不同催化剂用量及不同溶液pH条件下对MB光降解效率的影响。结果表明,三维多孔的纤维素气凝胶的使用提高了对MB的吸附能力,延长了对可见光的吸收。特别是在纤维素基体中掺杂的Cu2O在光照下激发出电子-空穴,增加了活性位点,从而提高了催化能力。6wt%Cu2OPVA/CNF复合催化剂对MB的光降解率达到95.6%,远高于纯Cu2O的79.6%。Cu2O-PVA/CNF复... 相似文献