TiO2纳米管的光催化降解SDBS实验

自1972年日本学者Ｆｕｊｉｓｈｉｍａ和Ｈｏｎｄａ[1] 报道了在光电池中受辐射的ＴｉＯ2 可以持续地致使水分解产生Ｈ2 以来 ,多相光催化技术吸引了科技工作者强烈的兴趣 .目前 ,在多相光催化反应所应用的半导体催化剂中 ,ＴｉＯ2 以其价廉、无毒、光催化活性高、稳定性好而备受青睐 .在使用ＴｉＯ2 光催化降解有机分子时 ,以ＴｉＯ2 纳米粉体[2 ] 或纳米膜[3] 的研究较为普遍 .本文报道以多孔阳极氧化铝为模板制备出ＴｉＯ2 纳米管 ,以及ＴｉＯ2 纳米管在光催化降解低浓度的十二烷基苯磺酸钠 (ＳＤＢＳ)溶液方面作的初步研究结果 .关于多孔…     

TiO2纳米管的制备方法研究

研究了目前常用的TiO2纳米管阵列的制备方法:模板法,水热合成法和阳极氧化法,对阳极氧化法经常采用的几个电解液体系也做了相应的讨论.本文通过对比不同制备方法所需的实验条件以及所得到的纳米管的形貌,优选出更适合进一步研究的制备方法.阳极氧化法制备的 TiO2 纳米管具有高度有序的纳米阵列结构,并且制备方法简单易行,其缺点在于成本较高.     

TiO2纳米管阵列的制备与表征

研究了阳极氧化备TiO_2纳米管阵列过程中电解液中水的含量、阳极氧化时间、阳极氧化电压、退火处理对TiO_2纳米管阵列形貌以及晶型的影响。结果表明:当电解液中水的含量为2%(V/V)时,制得的TiO_2纳米管阵列形貌清晰可见,管口完好无损;450℃退火使纳米管由无定形态转变为锐钛矿相。     

脉冲电沉积法制备Pd-Pt合金纳米线及吸氢性能的研究

氢气易燃易爆,在工业生产中,快速、准确地对其进行检测是非常必要的.采用AAO模板法制备Pd-Pt合金纳米线,电化学沉积溶液的配制如下:60 mmol/L的PdCl2+40 mmol/L的H2PtCl6·6H2O+0.2 mol/L的H3BO3,pH值为5.9.实验参数选择设置为-0.4V(1s),0 V(3 s),沉积...     

纳米TiO2壳聚糖模板法制备及其光催化性能

以壳聚糖为模板剂,采用溶胶-凝胶法制备了平均粒径为15nm,具有较高分散性、热稳定性和光催化活性的纳米TiO2粒子.采用扫描电镜(SEM)、透射电镜(TEM)、X射线粉末衍射(XRD)、傅立叶红外光谱(FT-IR)以及紫外-可见光谱(UV-vis)等手段对产物进行了分析和表征.条件实验结果表明,在500℃下灼烧1h所得TiO2产物由锐钛矿相及少量金红石相构成.光催化实验结果表明,所得产物在日光下对有机染料亚甲基蓝有很好的催化降解作用.     

载铂TiO2纳米管的制备及其光催化性能

将水热法制得的钛酸纳米管分别在300,400,500℃焙烧5h,得到含有一定量锐钛矿相的TiO2纳米管(ti-tania nanotubes,TNT).以该TNT为基体,H2PtCl6.6H2O为铂源,采用光还原沉积法制得载铂TiO2纳米管.通过X-射线衍射、透射电镜及X-射线光电子能谱等分析手段对制得纳米管的形貌、结构及组成进行了表征.以罗丹明B为模型污染物研究了载铂TiO2纳米管的光催化性能.结果表明:TiO2纳米管载铂后对罗丹明B的光催化降解效率比载铂前有较大提高,且洗去TNT外表面氯铂酸后制得的仅在纳米管内表面负载铂的TiO2纳米管具有更高的光催化活性.     

磷酸电解液中TiO2纳米管的形貌及光吸收性能研究

采用阳极氧化法在磷酸电解液中制备TiO2纳米管,通过SEM 和UV-VIS-DRS表征分析,研究阳极氧化电压、氧化时间、煅烧温度、电解液组成等制备条件对 T iO2纳米管形貌和光吸收性能的影响．结果表明,在H3 PO4电解液体系中,阳极氧化法制备 T iO2纳米管的最佳条件为：阳极氧化电压20V ,阳极氧化时间60min ,V（H3 PO4）∶V（NH4 F）＝1∶1,煅烧温度为500℃．此时纳米管管径80～100nm ,在可见区有较强的吸收且吸收边界红移．     

TiO2纳米管阵列的制备及其光催化效率研究

以质量分数（下同）0.3%NH4F＋ethylene glycol＋1%H2O为电解液采用阳极氧化法制备了TiO2纳米管,研究了阳极氧化时间和退火温度对TiO2纳米管表面形貌、晶体结构和光催化效率的影响,比较了不同电解液制备的TiO2纳米管和溶胶凝胶法制备的TiO2薄膜的光催化效率.应用X射线衍射（XRD）和场发射扫描电镜（FESEM）对TiO2纳米管的形貌和结构进行了分析.结果表明：在阳极氧化恒电压50 V、阳极氧化48 h、450℃退火4 h条件下制备的TiO2纳米管具有最高的光催化效率,其光催化效率明显高于溶胶凝胶法制备的TiO2薄膜（4.4倍）,也高于0.5%HF电解液和弱酸水溶性电解液（0.5%HF＋1 mol/L NH4H2PO4）制备的TiO2纳米管的光催化效率.     

阳极氧化法制备纳米氧化铝模板及对其在纳滤过程中的研究

采用阳极氧化法,以硫酸和草酸为电解液制备了纳米氧化铝模板．讨论在不同酸体系中所得到的模板的特征．利用表面活性剂解决了纳米金刚石的软团聚问题,研究了纳米金刚石通过模板的行为．实验表明,纳米氧化铝模板可以用作纳米金刚石的筛分．     

多孔氧化铝模板的快速制备

提出一种快速制备多孔氧化铝(anodic aluminum oxide,AAO)模板的新方法.以0.3 mol·L-1草酸溶液为电解液,利用两阶段升压法,在0 C和120 V条件下制备AAO模板.该方法的成膜速率达到1.1 μm·min-1,比传统低电压(50 V)制备条件下的成膜速率提高近20倍.通过控制AAO模板在0.8 mol·L-1磷酸溶液中的腐蚀时间,可使模板孔径在40～120 nm范围调节.     

Synthesis of carbon nanotube arrays using ethanol in porous anodic aluminum oxide template

Carbon nanotube (CNT) arrays confined by porous anodic aluminum oxide (AAO) template were synthesized using ethanol as reactant carbon source at low pressure. Images by scanning electron microscope (SEM) and low magnification transmission electron microscopy (TEM) show that these CNTs have highly uniform outer diameter and length, absolutely controlled by the diameter and depth of nano-channel arrays of the AAO. High resolution transmission electron microscopy (HRTEM) imaging indicates that the graphitization of the CNT walls is better than the results reported on this kind of template-based CNT arrays, although it is not so good as that of multiwalled carbon nanotubes (MWCNTs) synthesized by catalysis. CNTs synthesized using acetylene as reactant gas show much less graphitization than those prepared using ethanol by comparing the results of HRTEM and Raman spectroscopy. The etchingeffects of decomposed OH radicals on the amorphous carbon and the roughness of AAO nano-channel arrays on the CNTs growth were employed to explain the graphitization and growth of the CNTs.     

Well-aligned carbon nanotube array membrane synthesized in porous alumina template by chemical vapor deposition

A new simple approach was devetoped for preparing wetl-aligned and monodispersed carbon nanotube (CNT) array membrane within the cylindrical pores of anodic aluminum oxide (AAO) template by chemical vapor deposition (CVD). Acetylene and hydrogen were used in the CVD process with Fe-catalyzer at 700°C under 250 Pa. Scanning etectron microscope (SEM) and transmission etectron microscope (TEM) were employed to characterize the resulting highly-oriented uniform hollow tube array which had a diameter of about 250 nm, a tube density of 5.3x10⁸ cm² and a length of about 60 μm. The length and diameter of the tubes depend on the thickness and pore diameter of the template. The growth properties of the CNT array film can be achieved by controlling the structure of the template, the particle size of Fe-catalyzer, the temperature in the reactor, the flow ratio and the deposition time. The highly-oriented and uniform CNT array membrane fabricated by this simple method is very much useful in a variety of applications.     

大孔径多孔氧化铝膜的制备

本文使用磷酸和草酸的混合溶液为电解液,在90V电压下,控制电解液温度在5～10℃制备了平均孔径高达200nm,开孔密度为1.7×109pores/cm2的多孔阳极氧化铝（AAO）膜。与使用单一酸为电解质相比,使用混合酸制备大孔径氧化铝膜所需的电压较低,电流密度较小,对氧化温度的要求也不苛刻。     

石墨烯薄膜的化学气相法制备及光、电特性研究

利用化学气相沉积方法制备了石墨烯薄膜,并研究了其光电特性。以乙醇做反应原料、氩气作为携载气体,在873 K、973 K、1 073 K的温度下合成石墨烯薄膜。应用光学显微镜观察,发现在1 073 K时能够制备大面积均匀、平整光滑的石墨烯薄膜。纳曼光谱分析结果表明:制备的石墨烯薄膜出现2 650 cm-1的石墨烯的特征峰-D强峰,同时该峰强度随温度的升高而迅速增强,说明低温不能使沉积的碳原子有效的石墨化为石墨烯,而较高的温度有助于乙醇分解并石墨化为石墨烯薄膜。在1 073 K时沉积的石墨烯薄膜具有良好的光、电特性,其电子迁移率可以达到104 cm2.(V.s)-1,光透射率达97%,因此,可用于制备石墨烯晶体管、太阳能电池等光电子器件。     

多孔氧化铝膜调制的银纳米颗粒的表面增强荧光效应

采用氧化还原方法,在多孔氧化铝膜（Anodic Aluminum Oxide,AAO）模板中直接反应生成银纳米颗粒（SNPs）,制备出一种新型的AAO/SNPs纳米复合结构衬底.在532nm连续激光的激发下,研究了位于该纳米复合衬底上Rh6G分子的荧光增强效应.结果表明,AAO/SNPs纳米复合衬底对Rh6G的荧光发射强度与未经SNPs修饰的AAO对Rh6G的荧光发射强度相比,增强倍数可达6倍左右,而且荧光增强因子与AAO的孔径大小有关.此外本文还运用局域场增强理论对纳米复合体系中的荧光增强效应进行了分析讨论,并探讨了空间周期调制的金属纳米复合衬底对表面增强荧光效应的独特优点.     

Synthesis of ordered Si nanowire arrays in porous anodic aluminum oxide templates

Highly ordered polycrystalline Si nanowire arrays were synthesized in porous anodic aluminum oxide (AAO) templates by the chemical vapor deposition (CVD) method. The morphological structure, the crystal character of Si nanowire arrays and the individual nanowire were analyzed by the transmission electron microscopy (TEM), scanning electron microscopy (SEM), atom force microscopy (AFM) and the X-ray diffraction spectrum (XRD), respectively. It is shown that most fabricated silicon nanowires (SiNWs) tend to be assembled parallelly in bundles and constructed with highly orientated arrays. This method provides a simple and low cost fabricating craftwork and the diameters and lengths of SiNWs can be controlled, the large area Si nanowire arrays can be achieved easily under such a way. The curling and twisting SiNWs are fewer than those by other synthesis methods.     

Fabrication and characterization of crystalline copper nanowires by electrochemical deposition inside anodic alumina template

Copper nanowires were fabricated by electrochemical deposition inside anodic alumina template anodized on aluminum substrate. The morphology, composition and structure of the copper nanowires were characterized by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), energy-dispersive (EDS) and X-ray diffraction spectroscopy (XRD). The results revealed that copper nanowires were dense, continuous, highly-crystalline and uniform with diameters. The electrical properties of copper nanowires wrer characterized with two-terminal electrical measurements. Different current-voltage (I-V) characteristics of single copper nanowire were observed and possible conductive mechanisms were discussed. The crystalline copper nanowires are promising in application of future nanoelectronic devices and circuits.     

基于挤出沉积成形技术的多孔生物支架制备

利用精密挤出沉积自由成形技术制备骨组织工程用羟基磷灰石多孔生物支架,探讨工艺参数对支架孔洞成形的影响,评价支架的力学性能并分析影响强度的微观因素.结果表明：通过调整工艺参数,采用挤出沉积工艺可制备出具有可控结构、良好连通性的生物支架;支架具有良好的力学性能,经过微波烧结处理后,孔隙率为56.2%的支架平均抗压强度为45.2MPa,致密化程度与晶粒尺寸是影响支架强度的主要微观因素.同时,该结构的支架能够为细胞的分化与新生组织的生长提供持续的强度支持,满足组织工程支架结构与力学性能要求.     

Growth and optical absorption properties of silver nanorod arrays in porous anodic aluminum oxide templates

Silver nanorod arrays have been fabricated by alternat-ing current(AC) and pulsed direct current(DC) electrodeposition in porous anodic aluminum oxide(AAO) templates with controlled pore diameters of 19,38,and 65 nm,respectively.The variation of their optical absorption properties with the incident angle and the nanorods length(corresponding to the electrodeposition time) has been investigated.Optical absorption spectra show that the posi-tion of longitudinal surface plasmon resonance(LSPR) peak has a small blueshift with the increase of incident angle of the excitation light.While the aspect ratio of the nanorods increases,the position of LSPR peak first redshifts and then blueshifts to a certain wave-length.Furthermore,the position of LSPR peak can be tuned,ranging from 550 nm to 900 nm,which makes it possible to cou-ple various wavelength of excitation source to assist radiative en-ergy transfer to the acceptor.