ZnO纳米棒的制备及其光催化活性研究

以Zn(Ac)2·2H2O、NaI和N2H4·H2O为原料,在未使用任何表面活性剂的简单水热反应体系中制得了ZnO纳米棒.采用X射线粉末衍射仪(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)对产物的晶体结构、形貌进行了表征分析,并对其光催化活性进行了探讨,以ZnO纳米棒为光催化剂对有机染料污染物甲基橙进行了光催化降解实验.实验结果表明,氧化锌纳米棒对甲基橙的光催化降解具有很好的催化作用,在紫外光照射120min后,对甲基橙的降解率接近完全.     

ZnO/AgBr复合纳米棒的制备及其光催化性能研究

以ZnNO3·6H2O、AgNO3、十六烷基三甲基溴化铵和氨水为原料,通过水热法制备了ZnO/AgBr复合纳米棒.利用SEM、XRD分别对产品的形貌和结构进行表征.以ZnO/AgBr复合纳米棒为光催化剂,通过降解有机污染物甲基橙进行了光催化活性测试,结果表明,在可见光照射150 min后,对甲基橙的降解率接近完全.     

硬脂酸修饰纳米氧化锌的制备及可见光光催化性能研究

以硫酸锌和氢氧化钠为原料,硬脂酸为修饰剂,采用一步沉淀法制备出硬脂酸修饰的纳米ZnO,并对可见光光催化性能进行了研究。借助XRD、TEM、FTIR、UV-vis等测试手段对硬脂酸修饰的纳米ZnO进行表征。结果表明,硬脂酸修饰的纳米ZnO分散比较均匀,硬脂酸与纳米氧化锌之间形成了化学键,而且硬脂酸修饰后,纳米ZnO更易被可见光激发,当甲基橙初始浓度为5 mg/L,硬脂酸修饰的纳米ZnO投加量为10 mg/L,光照时间70 min,硬脂酸修饰的纳米ZnO对甲基橙的降解率达到82.3%。     

簇状氧化锌纳米棒的合成及其光催化性能研究

采用醋酸锌和氨水为原料、水作为溶剂,以水热法在80℃条件下反应20 h制备出了簇状氧化锌纳米棒,用XRD、SEM分别分析了制备产物的物相和形貌。以ZnO纳米棒为光催化剂对有机染料甲基橙进行了光催化降解实验,研究了甲基橙溶液初始浓度和催化剂添加量对光催化的影响。结果表明,合成的氧化锌纳米棒均为六方晶系铅锌矿结构;产物为从中心发散的簇状纳米棒结构,纳米棒直径分布均匀且分散性好,每个簇由几十个纳米棒组成,每个纳米棒平均直径约为150 nm,长度约为5μm。制备的ZnO有良好的光催化性能。     

ZnO光催化降解甲基橙初步研究

研究了ZnO光催化降解甲基橙的动力学行为。在ZnO悬浊液中 ,紫外光直接照射下 ,光催化降解甲基橙 ,以分光光度法测量甲基橙即时浓度 ,从而给出不同温度下甲基橙降解脱色速率 ,并以之得出了该反应的活化能数据。实验结果表明 ,ZnO光催化甲基橙在常温下降解脱色速率基本上与温度无关 ,随温度升高小幅提高。ZnO催化能力比较强 ,可进一步研究使之实际应用。     

牡蛎壳粉为载体的纳米ZnO光催化降解甲基橙的研究

以Zn(NO3)2·6H2O和Na2CO3为原料,采用沉淀法制备了以牡蛎壳粉为载体的纳米ZnO催化剂. 以高压汞灯(主波长365 nm)为光源,以所制备纳米ZnO催化降解甲基橙溶液,研究了催化剂用量、甲基橙初始浓度、光照时间、光强度等对甲基橙光催化降解效果的影响.结果表明,ZnO用量为3 g·L-1时,甲基橙降解率最高.     

微波闪速合成纳米ZrO_2/ZnO复合材料及其光催化性能研究

以硝酸锆和硝酸锌为原料,尿素为助燃剂,采用微波闪速法合成纳米ZrO2/ZnO复合材料,研究了纳米ZrO2/ZnO复合材料分别对甲基橙和罗丹明B的光催化降解性能。结果表明,在紫外光条件下,纳米ZrO2/ZnO复合材料光催化降解甲基橙效果明显优于罗丹明B。     

Ag/ZnO复合材料的制备及其光催化研究

通过光还原沉积改性法制备了含不同含量Ag的Ag/ZnO复合材料(0.5%,1%,2%,5%,10%),对其进行了X射线衍射,扫描电子显微镜表征,并利用光催化降解甲基橙溶液研究复合材料的光催化性能。结果表明:Ag仅负载在ZnO粒子表面上而未进入其晶格内。Ag/ZnO复合材料可以有效地降解甲基橙;适量的Ag修饰ZnO可大大提高Ag/ZnO复合材料的光催化活性。过大的沉积量会导致Ag的浪费,且会使Ag/ZnO原子簇增大,不利于光催化反应的效率提高。     

水热法制备的纳米氧化锌阵列及在棉织物上的应用

以硝酸锌和六亚甲基四胺为原料,采用低温水浴法在棉织物表面实现ZnO纳米棒阵列生长的控制,并探讨了反应物溶液的浓度、反应温度、反应时间对ZnO纳米棒阵列生长的影响,同时对所制备的样品进行了抗紫外、光催化等测试、表征及性能分析。结果表明:棉织物表面生长的ZnO纳米棒结构为六方纤锌矿晶体;在反应物溶液浓度为0.025 mol/L,反应温度为90℃,反应时间为3 h时,制备得到形貌规整和定向生长的ZnO纳米棒阵列,赋予棉织物良好的光催化、抗紫外、自清洁等性能。     

微波均相沉淀法制备纳米ZnO及其光催化性能

以硫酸锌和尿素为原料,采用微波均相沉淀法制备出了纳米ZnO. 探讨了反应物配比、反应物浓度、反应时间、反应温度等条件对产物的影响. 并用TEM, IR, TGA, XRD, UV-Vis等测试手段对其进行了表征. 利用紫外-可见分光光度计测试了光吸收特性,发现纳米ZnO对200~380 nm波长范围的光有很强的吸收性,在可见光范围内也有较强的吸收. 研究了纳米ZnO光催化降解甲基橙的动力学行为,在紫外光直接照射下,光催化降解甲基橙,以分光光度法测量甲基橙的即时浓度,从而得出了不同条件下甲基橙降解的脱色速率,以比较不同的降解效果.     

Hydrogen treatment-improved uniform deposition of Ag nanoparticles on ZnO nanorod arrays and their visible-light photocatalytic and surface-enhanced Raman scattering properties

ZnO nanorod arrays were synthesized by chemical bath deposition. After heat treatment in hydrogen or air, Ag nanoparticles were deposited on ZnO nanorod arrays by photo-reduction method. The size of Ag nanoparticles as well as the surface morphology, structure, composition, and optical property of ZnO nanorod arrays before and after the deposition of Ag nanoparticles were characterized by SEM, XRD, EDS, and UV/VIS/NIR spectrophotometer. As compared to the samples with heat treatment in air or without heat treatment, the ZnO nanorod arrays after heat treatment in hydrogen allowed Ag nanoparticles to be deposited more uniformly, densely, and numerously. Also, they exhibited higher efficiency for the visible light-driven photocatalytic degradation of Rhodamine 6G (R6G) dye. The effects of the amount of Ag nanoparticles, initial dye concentration, and temperature on the photocatalytic degradation efficiency were investigated. Furthermore, they also exhibited better surface-enhanced Raman scattering property for the detection of R6G dyes.     

Photocatalytic activity of TiO2 nanotube layers coated with Ag and Pt

Abstract

Abstract

Thin films of anatase TiO₂ nanotube arrays (TiO₂ NTs) were prepared in this study. Pt and Ag were coated on the TiO₂ NTs films, which intend to increase the photocatalytic activity under ultraviolet-visible (UV-vis) irradiation. The phase and structure of the films were investigated by X-ray diffraction and scanning electron microscopy. Photocatalytic activity was tested by UV-vis absorption spectroscopy and showed that UV-vis light absorption of the films was remarkably improved by coated Ag and Pt by 72% and 183% respectively. The photocatalytic activities of the films towards degraded methyl orange and HCHO were compared and were all found to follow the sequence Pt/TiO₂ NTs>Ag/TiO₂ NTs>TiO₂ NTs. It was also found that the kinetics of HCHO photocatalytic degradation by the films fits the first order reaction model better and has higher efficiency than that of the methyl orange photocatalytic degradation by the same films.     

单壁碳纳米管显著增强的ZnO可见光催化活性

利用醋酸锌为原料,采用溶胶-凝胶法制备了单壁碳纳米管（SWMTs）和氧化锌的纳米复合物（ZnO/SWNTs）。用X射线衍射光谱（XRD）、拉曼光谱、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、热重分析（TGA）、傅里叶变换红外光谱（FT-IR）以及紫外-可见吸收光谱（UV-Vis）对复合物进行了表征。结果显示,粒径为10～20 nm的ZnO粒子均匀地负载在SWNTs表面,且在可见光区具有很好的光吸收性能。研究了ZnO/SWNTs光催化剂在太阳光照射下对甲基橙和亚甲基蓝的光催化降解情况。结果表明,复合物的催化活性明显高于ZnO。对于甲基橙,光照200 min后,降解率为99.8%,是纯ZnO（4.8%）的20倍;对于亚甲基蓝,仅光照20 min,降解率就达到了98.4%,是纯ZnO（4.0%）的25倍。     

Y掺杂ZnO的制备及其光催化性能

采用化学沉淀法制备Y/ZnO光催化剂,以光催化降解甲基橙为探针反应,考察Y掺杂的ZnO光催化活性,并采用X射线衍射、红外光谱和紫外漫反射等手段对其进行结构表征.结果表明,Y掺杂的ZnO光催化剂对甲基橙降解具有良好的活性.活性及催化剂结构表征结果表明,最佳Y掺杂质量分数为0.1%,以掺杂Y质量分数为0.1%的Y/ZnO为...     

Preparation of Ag-sensitized ZnO and its photocatalytic performance under simulated solar light

ZnO was prepared rapidly by microwave heating method. The results of scanning electron microscopy show that the leaflike ZnO is composed of self-assembled ZnO particles of 30–50 nm. Ag-sensitized ZnO composite was prepared by UV-photoreduction and glycol reduction, respectively. The composite was characterized by means of scanning electron microscopy, X-ray diffraction and photoluminescence. The ZnO and Ag/ZnO prepared were applied in photocatalytic degradation of phenol and methyl orange as model of organic pollutant in water under simulated solar light. The results show that Ag doping in both methods of UV-photoreduction and glycol reduction can remarkably improve the photocatalytic activity of ZnO under simulated solar light. The utilization ratio of Ag in glycol reduction is high and the optimum content of Ag in Ag/ZnO composite is only 1.33%. Therefore, the glycol reduction is a novel and excellent method for preparing Ag-sensitized ZnO composite with high photocatalytic activity.     

Construction of Z-scheme type CdS–Au–TiO2 hollow nanorod arrays with enhanced photocatalytic activity

The Z-scheme type CdS–Au–TiO₂ hollow nanorod arrays have been constructed on glass substrates by following these simple steps: firstly, highly ordered TiO₂ hollow nanorod arrays (THNAs) were synthesized by liquid phase deposition (LPD) using ZnO nanorod arrays as templates; then both Au core and CdS shell nanoparticles were achieved on the THNAs by in situ photodeposition. The prepared three-component films were characterized by field-emission scanning electron microscopy (FSEM), high-resolution transmission electron microscope (HRTEM), Raman scattering and ultraviolet–visible absorption spectrum. The results showed that Au–CdS core–shell nanoparticles were well dispersed on wall of anatase THNAs from top to bottom. The three-component nanojunction system was evaluated for their photocatalytic activity through the degradation of methylene blue (MB) in aqueous solution. It was found that the CdS–Au–TiO₂ three-component hollow nanorod arrays exhibited significantly enhanced photocatalytic activity compared with single (THNAs) and two components (Au-THNAs or CdS-THNAs) systems. Reasons for this enhanced photocatalytic activity were revealed by photoluminescence (PL) results of our samples.     

不锈钢丝网上氧化锌纳米线阵列的 可控生长及光催化性能研究

利用水热法在不锈钢丝网上制备了氧化锌纳米线阵列,借助扫描电镜（SEM）对产物的形貌进行了表征,探讨了反应物浓度和反应时间对产物形貌的影响,并以橙黄Ⅱ为目标降解物,研究了不同生长条件下氧化锌纳米线阵列的光催化降解性能。研究结果表明：硝酸锌浓度和反应时间对氧化锌纳米线阵列的密度、长度、直径和晶形有重要影响,在硝酸锌浓度为0.1 mol/L、反应时间为6 h条件下,制得的氧化锌纳米线阵列具有较佳的光催化活性,多次循环实验结果表明其稳定性较高。另外,双层叠合的氧化锌纳米线的光催化降解性能优于单层氧化锌纳米线的实验结果,其不锈钢丝网的网状结构为制备多维纳米阵列和薄膜提供了一种新的研究思路。