贵金属负载的棒状ZnO复合光催化剂的制备及其提升的光催化性能

以水热制备的ZnO纳米棒为基底,通过乙二醇液相还原法负载不同贵金属颗粒(Pt、Pd、Ru)构筑贵金属负载的ZnO纳米棒复合光催化剂。实验结果表明在制备条件相同时,Pt/ZnO样品中Pt颗粒尺寸较小,分布均匀;Pd/ZnO样品中Pd颗粒尺寸较大且团聚严重;Ru/ZnO样品则几乎没有Ru颗粒负载。在紫外光照射下降解亚甲基蓝的反应中,Pt/ZnO表现出最高的光催化性能,Pd/ZnO样品次之,而Ru/ZnO则表现出与ZnO纳米棒相似的光催化活性;表明小尺寸和大小均匀的贵金属颗粒对ZnO纳米棒的催化性能有着显著的提升作用。对Pt/ZnO来说,当Pt载量为3.2%时Pt/ZnO催化剂的光催化活性最高。     

具有核壳结构的ZnO纳米棒@Ni-Co双氢氧化物复合物纳米片阵列的制备及其电化学性能

通过两步水热合成法制备了具有核壳结构的ZnO纳米棒@Ni-Co双氢氧化物复合材料纳米片阵列.首先,以碳布为基底,水热法生成的ZnO沉积在碳布上形成ZnO纳米棒花簇.其次,以ZnO纳米棒为模板,水热法生成的Ni-Co双氢氧化物纳米片沉积在ZnO纳米棒表面,形成ZnO纳米棒@Ni-Co双氢氧化物纳米片复合材料阵列.形貌、结构分析和电化学性能测试表明,以碳布为基底,成功地合成了以ZnO纳米棒为模板并具有核壳结构的ZnO纳米棒@Ni-Co双氢氧化物复合材料纳米片阵列,该复合材料纳米片阵列具有较大的纵横比,且分散均匀.合成的ZnO纳米棒@Ni-Co双氢氧化物复合材料纳米片阵列具有良好的电化学性能,当电流密度为1 A/g时,其比电容值可达531.6 F/g,该复合材料在超级电容器电极材料领域具有良好的应用前景.     

液相沉积法制备ZnO/CdS复合纳米棒阵列薄膜及其光电性质

采用两步化学溶液沉积法在氧化铟锡(ITO)导电玻璃衬底上制备了ZnO/CdS复合纳米棒阵列薄膜.利用X射线衍射(XRD)仪、扫描电子显微镜(SEM)、紫外-可见(UV-Vis)吸收分光光度计、荧光(PL)光谱仪及表面光电压谱(SPS)研究了不同CdS沉积时间对复合薄膜的晶体结构、形貌、光电性质的影响.研究结果表明:ZnO纳米棒阵列表面包覆CdS纳米颗粒后,其吸收光谱可拓展到可见光区;与吸收光谱相对应在可见光区出现新的光电压谱响应区,这一现象证实,通过与CdS复合可显著提高ZnO纳米棒阵列在可见光区的光电转换性能;随着CdS纳米颗粒沉积时间的延长,复合纳米棒阵列薄膜在大于383nm波长区域的光电压强度逐渐减弱,而在小于383nm波长区域的光电压强度逐渐增强.用两种不同的电荷产生和分离机制对这一截然相反的光响应过程进行了详细的讨论和解释.     

P3HT/CdS/TiO2/ZnO一维有序核壳式纳米棒阵列的构制及其在杂化太阳电池中的应用研究

采用恒电位法在铟锡氧化物导电玻璃(ITO)上制备了高度有序一维ZnO纳米棒阵列,将ZnO纳米棒阵列在TiO2溶胶中采用提拉法制备出了一维TiO2/ZnO核壳式纳米棒阵列.在一维TiO2/ZnO核壳式纳米棒阵列上电沉积CdS纳米晶得到一维CdS/TiO2/ZnO核壳式纳米棒阵列,然后在一维CdS/TiO2/ZnO核壳式纳米棒阵列上电沉积聚3-己基噻吩(P3HT)薄膜得到P3HT/CdS/TiO2/ZnO核壳式纳米结构薄膜.以该纳米结构薄膜电极为光阳极制备出新型纳米结构杂化太阳电池,研究了该类电池的光电转换性能,初步探讨了该类电池的工作机理.     

低压近场静电纺丝ZnO/PVDF复合微米纤维阵列的制备及压力传感性

利用低压近场静电纺丝技术制备了ZnO/PVDF(聚二偏氟乙烯)微米纤维平行阵列, 通过光学显微镜、扫描电子显微镜(SEM)和X射线能量色散光谱(EDS)对ZnO/PVDF微米纤维进行了表征. 该复合纤维的平均直径约为40 μm. EDS分析测试证明ZnO纳米颗粒已经掺杂进入了平行微米纤维中. 压电性能和电学性能测试结果表明, ZnO/PVDF微米纤维阵列的压电性能增强. 研究结果表明, 近场电纺丝ZnO/PVDF复合微米纤维阵列在压电型压力传感器和纳米发电机领域具有潜在的应用价值.     

低压近场静电纺丝ZnO/PVDF复合微米纤维阵列的制备及压力传感性（英文）

利用低压近场静电纺丝技术制备了ZnO/PVDF(聚二偏氟乙烯)微米纤维平行阵列,通过光学显微镜、扫描电子显微镜(SEM)和X射线能量色散光谱(EDS)对ZnO/PVDF微米纤维进行了表征.该复合纤维的平均直径约为40μm.EDS分析测试证明ZnO纳米颗粒已经掺杂进入了平行微米纤维中.压电性能和电学性能测试结果表明,ZnO/PVDF微米纤维阵列的压电性能增强.研究结果表明,近场电纺丝ZnO/PVDF复合微米纤维阵列在压电型压力传感器和纳米发电机领域具有潜在的应用价值.     

金修饰ZnO纳米棒阵列制备及对甲醛气敏性能

通过两步溶液法在氧化铝陶瓷管上先制备出ZnO纳米棒阵列,再用真空蒸镀法在ZnO纳米棒表面形成一层均匀Au膜,于500℃下热处理得到Au纳米颗粒修饰的ZnO(Au-ZnO)纳米棒阵列体系。通过场发射扫描电子显微镜(FE-SEM)和X射线衍射仪(XRD)对ZnO纳米棒阵列和Au-ZnO纳米复合体系进行表面形貌表征和结构分析。气敏性能测试结果表明,Au-ZnO纳米复合体系在300℃下对1000μL·L-1甲醛的灵敏度为41.5,而在200℃下灵敏度仍能达到10.3,表明可以制备低工作温度下气敏性能良好的甲醛气敏传感器。     

CdS量子点敏化ZnO纳米棒阵列电极的制备和光电化学性能

采用连续式离子层吸附与反应法制备了CdS量子点敏化的ZnO纳米棒电极.应用扫描电子显微镜(SEM)、X射线衍射(XRD)和透射电子显微镜(TEM)对CdS量子点/ZnO纳米棒电极的形貌、晶型和颗粒尺寸进行了分析和表征;采用光电流-电位曲线和光电流谱研究了不同CdS循环沉积次数及不同沉积浓度对复合电极的光电性能影响.结果表明,前驱体浓度都为0.1mol·L-1且沉积15次敏化后的ZnO纳米棒阵列电极光电性能最好.与单纯的ZnO纳米棒阵列电极和单纯的CdS量子点电极相比,其光电转换效率显著提高,单色光光子-电流转换效率(IPCE)在380nm处达到76%.这是因为CdS量子点可以拓宽光的吸收到可见光区,并且在所形成的界面上光生载流子更容易分离.荧光光谱实验进一步说明了光电增强的原因是,两者间形成的界面中表面态大大减少,有利于减少光生电子和空穴的复合.     

P3HT修饰一维有序壳核式CdS/ZnO纳米棒阵列复合膜的光电化学性能

采用电化学方法在铟锡氧化物(ITO)导电玻璃上制备了高度有序的ZnO纳米棒阵列, 在ZnO纳米棒阵列上先后电化学沉积CdS纳米晶膜及聚3-己基噻吩(P3HT)薄膜得到P3HT修饰的一维有序壳核式CdS/ZnO纳米阵列结构, 并通过扫描电镜(SEM)、透射电镜(TEM)、X射线衍射(XRD)、能量散射X射线(EDX)等表征手段证实了该结构的形成. 以此纳米结构薄膜为光阳极组装新型半导体敏化太阳电池, 研究了CdS纳米晶膜的厚度和P3HT薄膜的沉积对电池光伏性能的影响, 初步探讨了电荷在电池结构中的传输机理, 结果表明, CdS纳米晶膜和P3HT薄膜的沉积有效地拓宽了光阳极的光吸收范围, 实验中电池的光电转换效率最高达到1.08%.     

原位生长的α-Fe2O3/ZnO异质纳米棒阵列对乙醇气体的高选择性检测

采用两步溶液法在陶瓷管上原位生长了ZnO纳米棒阵列,然后以ZnO纳米棒为载体,通过水热法在其表面负载α-Fe₂O₃纳米粒子,生成异质α-Fe₂O₃/ZnO复合纳米材料。 α-Fe₂O₃/ZnO纳米棒直径30~80 nm,长1 μm左右,交叉排列形成纳米棒阵列,α-Fe₂O₃纳米粒子粒径约10 nm,均匀分布在ZnO纳米棒表面。 将纯ZnO和α-Fe₂O₃/ZnO纳米棒阵列制成气敏元件,测试并对比了2种气敏元件的气敏性能,揭示其气敏机理。 结果表明:α-Fe₂O₃纳米粒子的复合显著提高了ZnO纳米棒阵列对乙醇气体的灵敏度和选择性,在工作温度370 ℃时,对100 μL/L乙醇气体的响应值为85.4,是同条件下ZnO器件对乙醇响应值(9.4)的9.1倍,响应时间7 s,最低检出限为0.01 μL/L。 相关研究可以应用于痕量乙醇的快速、高灵敏度和高选择性检测。     

电沉积种子层化学控制生长氧化锌纳米棒和纳米管

采用水溶液法在电沉积的ZnO种子层上制备了高度取向的ZnO纳米棒阵列,并通过碱溶液化学腐蚀法获得了ZnO纳米管。对ZnO纳米棒和纳米管的溶液生长和腐蚀过程进行了分析。结果表明,种子层的结构和性能对ZnO纳米棒有着重要的影响,在-700 mV电位下沉积的种子层薄膜均匀性好,生长的纳米棒密度大、与基底垂直性好;碱溶液对纳米棒的腐蚀具有选择性,通过控制腐蚀液的浓度和时间,可获得中空的ZnO纳米管。     

ZnO纳米棒阵列的同步法制备及其PL性能研究

在较低温度下，采用化学法在Zn片和玻璃片上同步制备了ZnO纳米棒阵列。利用XRD、FESEM和HRTEM对样品进行了表征，并且通过光致发光谱研究了阵列的光致发光(PL)性能。结果表明，ZnO纳米棒阵列较为致密、取向性较好。纳米棒为六方纤锌矿相，沿c轴生长，平均直径约为60 nm。同步法制备的2种ZnO纳米棒阵列均具有较好的紫外和橙红色发光性能，但发光特性却存在一定差异，这可能主要是由于2种阵列中纳米棒的缺陷含量不同所致。     

Low-temperature growth of ZnO nanorods by chemical bath deposition

Aligned ZnO nanorod arrays were synthesized using a chemical bath deposition method at normal atmospheric pressure without any metal catalyst. A simple two-step process was developed for growing ZnO nanorods on a PET substrate at 90-95 degrees C. The ZnO seed precursor was prepared by a sol-gel reaction. ZnO nanorod arrays were fabricated on ZnO-seed-coated substrate. The ZnO seeds were indispensable for the aligned growth of ZnO nanorods. The ZnO nanorods had a length of 400-500 nm and a diameter of 25-50 nm. HR-TEM and XRD analysis confirmed that the ZnO nanorod is a single crystal with a wurtzite structure and its growth direction is [0001] (the c-axis). Photoluminescence measurements of ZnO nanorods revealed an intense ultraviolet peak at 378.3 nm (3.27 eV) at room temperature.     

水热法制备高度取向的氧化锌纳米棒阵列

氧化锌的激子结合能(60meV)及光增益系数(300cm^-1)比GaN的(25meV,100cm^-1)还高,这一特点使它成为紫外半导体激光发射材料的研究热点。最近,Yang等成功地观测到规则的ZnO纳米线阵列的激光发射现象,更加激起了人们合成一维高度有序ZnO纳米结构的热情,由于一维ZnO     

ZnO纳米棒阵列到纳米管结构的自转化机制及其在相变封装材料中的应用

In the emerging field of nanoscience, tubular structures have been attracting remarkable interest due to their well-defined geometry, high specific area, and exceptional physical and chemical properties. Among them, oriented ZnO tubular arrays are regarded as promising candidates for various applications such as optoelectronics, solar cells, sensors, field emission, piezoelectrics, and catalysis. Although template-directed and selective dissolution synthesizing strategies are commonly used to prepare ZnO nanotubes, repeatability and large scale preparation are still challenging. In this study, ZnO nanotube arrays were controllably prepared by tuning the hydrothermal parameters, without the use of any additives. The mechanism underlying the self-conversion of ZnO nanorods to nanotubes was comprehensively studied based on the surface energy theory. It has been proved that the metastable top surface of the ZnO nanorods dissolves preferentially to reach a stable state during the hydrothermal growth. The specific surface energy of different crystal faces of ZnO nanorods was calculated using molecular dynamics simulation. The top surface of the ZnO nanorod, the Zn-terminated [0001] face, demonstrated much higher surface free energy than did the lateral faces, which indicated that the self-dissolution of top face (002) is energetically favorable. The self-conversion behavior of ZnO nanorod arrays with different diameters was specifically investigated by adjusting the initial precursor concentration, density of the crystal seed layers, and growth time. The dissolution-crystallization equilibrium concentration, determined by crystal surface energy, was found to be a key factor for the formation of the tubular structure. Notably, the critical equilibrium conditions for the self-conversion of ZnO nanorods to nanotubes, including zinc ion concentration and pH, have been identified by studying parameters corresponding to the dissolution-crystallization equilibrium for the metastable top surface of the ZnO nanorods. The preparation of the ZnO nanotube arrays was successfully accelerated and simplified via two-step procedure: (1) preparation of ZnO nanorod arrays and (2) self-conversion of ZnO nanorods to nanotubes. The preparation method based on the self-conversion mechanism from rods to tubes for polar oxides is simpler and more easily controllable as compared to the reported methods involving variety of additives. Because of the advantages of adaptability to a wide range of substrates, excellent conducting properties, and filling ability, the prepared ZnO nanotube array films were used in encapsulating phase-change materials. The encapsulated phase-change material exhibited excellent heat storage/release properties and heat conductivities. This indicates the potential application of precision devices for temperature control.     

Hydrothermal growth of well-aligned ZnO nanorod arrays: Dependence of morphology and alignment ordering upon preparing conditions

Well-aligned ZnO nanorod arrays were prepared on substrates by hydrothermal growth under different conditions. The effect of preparing conditions on the deposition of ZnO nanorods was systematically studied by scanning electron microscopy, X-ray diffraction and photoluminescence spectroscopy. It is demonstrated that the growth conditions such as pre-treatment of the substrates, growth temperature, deposition time and the concentration of the precursors have great influence on the morphology and the alignment ordering of ZnO nanorod arrays. Pre-treatment of substrates, including dispersion of ZnO nanoparticles and subsequent annealing, not only plays a main role in governing the rod diameter, but also greatly improves the rod orientation. Although the rod diameter and its distribution are mainly determined by pre-coated ZnO nanoparticles, they can also be monitored to some extent by changing the concentration of the precursors. The growth temperature has a little influence on the orientation of nanorods but it has great impact on their aspect ratio and the photoluminescent property. Kinetic studies show that the growth of ZnO nanorods contains two distinct step: a fast steps within the first hour, in which the nanorods tend to be short and wide, and a slow step, in which long rods with high aspect ratio are obtained.     

籽晶层制备方式对氧化锌纳米棒阵列的影响

采用3种不同的方式制备ZnO薄膜籽晶层:旋涂、喷雾热解和脉冲激光沉积。对于每一种制备方式,其薄膜的晶体结构、形貌、表面粗糙度等性能分别用X射线衍射(XRD)、扫描电子显微镜(SEM)和原子力显微镜(AFM)进行了表征。之后,通过水热合成方法,在3种籽晶层衬底上制备得到具有不同结构和形貌特征的ZnO纳米棒阵列。结果表明,ZnO纳米棒生长和籽晶层制备方式具有极强的相关性。最后,对两者相关性的生长机理进行了解释。     

ZnO纳米柱状阵列表面AgX等离子基元修饰及其可见光光催化活性

采用浸渍法制备了表面AgX（X=I,Br）等离子基元修饰的ZnO纳米柱状阵列,研究了浸渍浓度和时间以及紫外光光照预处理对ZnO纳米柱状阵列可见光光催化活性的影响.采用场发射扫描电子显微镜、X射线衍射仪、紫外可见漫反射吸收光谱以及X射线光电子能谱仪等手段对ZnO纳米柱状阵列的形貌、相组成、禁带宽度及其表面特性进行了表征.结果显示,AgBr颗粒分布于ZnO纳米柱状阵列的顶端及顶端侧面,同时AgBr颗粒之间相互接触而形成网状结构.通过紫外光光照预处理,AgBr表面出现细小颗粒,形成Ag/AgBr/ZnO纳米复合结构.可见光光催化降解甲基橙结果表明,在相同工艺条件下所制AgBr/ZnO的可见光光催化活性明显优于AgI/ZnO,且与浸渍浓度及时间有关.由于ZnO纳米柱状阵列的比表面积大,AgBr的可见光响应特性以及Ag/AgBr纳米结构的表面等离子效应,经过紫外光光照预处理形成的Ag/AgBr/ZnO纳米复合结构表现出最好的可见光光催化活性.