CuO/介孔TiO_2膜催化剂制备及光解水产氢性能研究

以介孔TiO_2膜(M-TiO_2)为基底,采用Cu_3(BTC)_2为前驱体法制备(mc)CuO/M-TiO_2和电化学沉积法制备(ed)CuO/M-TiO_2,并用于光解水产氢性能研究。通过SEM、XRD、拉曼光谱、PL和UV-Vis等多种手段对两种催化剂结构进行表征。结果发现(mc)CuO/M-TiO_2相对于(ed)CuO/M-TiO_2,其CuO颗粒尺寸较小。(mc)CuO/M-TiO_2对光的吸收效果、抑制光生电子-空穴对复合的能力皆远大于(ed)CuO/M-TiO_2,由此造成了(mc)CuO/M-TiO_2有着更好的光催化性能及稳定性。     

CuO在气敏传感器中的应用研究进展

综述了近年来CuO在气敏传感器中的应用研究进展,主要包括纳米结构CuO作为主体传感材料以及掺杂剂时的应用。着重介绍了一维CuO纳米线、纳米棒、纳米管的制备方法及其对常见多种可燃或有毒气体的气敏响应情况。指出了纳米结构CuO是今后CuO在气敏传感器中的重点发展方向,最后提出了CuO气敏材料应用时存在的一些问题以及今后的研究工作重点。     

CuO纳米线在碳纤维上的制备与表征

通过热氧化镀铜碳纤维,在碳纤维上制备了CuO纳米线。利用热重分析研究了镀铜碳纤维的热氧化过程。通过扫描电子显微镜、X射线衍射以及透射电子显微镜研究了退火温度、时间以及碳纤维对CuO纳米线生长的影响。结果表明,所制备的CuO纳米线为单斜型单晶结构,在碳纤维上制备CuO纳米线的最佳条件为400℃退火2h。并讨论了CuO纳米线在碳纤维上的生长机理。     

改进型[Cs,Rb]Na2KSb光阴极的制备研究

利用改进工艺制备的[Cs,Rb]Na2KSb光阴极,具有灵敏度高、热发射低和重复性好等优点,特别是改善了光谱的绿光到红外部分的光响应。提出的[Cs,Rb]Na2KSb光阴极的表面能带结构模型,对实验结果给予了比较满意的解释。     

改进型[Cs Rb]2OAg光阴极的制备研究

利用改进工艺制备的[Cs Rb]2OAg光阴极,具有灵敏度高、热发射低和重复性好等优点。特别是改善了变像管的背景亮度。并提出[Cs Rb]2OAg光阴极的表面能带结构模型,对实验结果给予了比较满意的解释。     

CuO/TiO_2异质多孔纳米结构的制备及其光催化性能

以Cu(OH)_2纳米棒阵列为前驱体,钛酸四丁酯为钛源,采用外向包覆合成法,利用Cu(OH)_2自身热分解产生的微量水分子与负载在其表面的钛酸四丁酯缓慢反应,制备了CuO/TiO_2异质多孔纳米结构,并研究了产物对罗丹明B(RhB)的光催化降解性能。结果表明,得到的产物薄膜为直径2~4μm的微孔组成的多孔纳米结构,微孔的孔壁由直径500nm左右的纳米棒组装而成。产物CuO/TiO_2异质多孔纳米结构比纯TiO_2纳米结构对RhB有更好的光催化降解性能,这主要是由两方面的原因引起的:一方面,CuO/TiO_2异质多孔纳米结构具有更好的吸附性能和更大的比表面积;另一方面,产物CuO/TiO_2为异质复合纳米结构,异质结的存在能有效地降低光生电子空穴对的复合,从而提高产物的光催化降解效果。     

直接沉淀法制备纳米CuO及室温脱除H2S性能的研究

考察了纳米CuO直接沉淀法制备工艺对其脱硫活性和晶粒尺寸的影响,并利用XRD和TEM对脱硫剂的结构进行了表征。结果表明,所制备的纳米CuO为单斜晶系结构。原料浓度过低、沉淀剂用量小均不利于生成小尺度的纳米CuO。但加热条件下,前驱体有分解形成CuO趋势,晶粒尺寸略有增大;当n(OH-)∶n(Cu2+)=2.5∶1,原料浓度0.4mol/L,搅拌温度为25℃,300℃焙烧时获得的纳米CuO脱硫活性最好,其穿透时间可达640min,此时纳米CuO晶粒尺寸为11.8nm,颗粒的分散性较好;纳米CuO的脱硫活性受其晶粒大小的影响,但只有晶粒尺寸相差较大时,两者之间才呈现出明显的相关性。     

Ⅲ-Ⅴ族光阴极简介

本文概述了一、二、三代光阴极发展史,重点综述第三代光阴极-Ⅲ-Ⅴ族光阴极的研究概况,特别是长波InGaAsP光阴极发展动向。     

CuO/CuxSy八面体核壳结构的合成及其电化学性能EI北大核心CSCD

在室温下通过离子交换过程,快速制备双壳层中空氧化铜/硫化铜(CuO/CuxSy)八面体材料.通过调节硫化时间,双壳层中空CuO/CuxSy八面体的形貌和硫化物/氧化物组成发生改变,进而影响其电化学性能.通过XRD,SEM,TEM和XPS对该八面体的形貌结构进行测试分析.测试表明该中空结构具有相互交叉的CuxSy纳米片构成的外壳和位于八面体内部的CuO核层部分.双壳层中空CuO/CuxSy八面体的独特结构和CuO,CuxSy之间的协同效应有利于材料的电化学过程.当硫化时间为6 h时双壳层中空CuO/CuxSy八面体在1 A·g^-1的电流密度下具有高达413.6 F·g^-1的比电容,并且其在20 A·g^-1的电流密度下具有较好的倍率性能和循环稳定性.     

CuO/Cu_xS_y八面体核壳结构的合成及其电化学性能

在室温下通过离子交换过程,快速制备双壳层中空氧化铜/硫化铜(CuO/Cu_xS_y)八面体材料。通过调节硫化时间,双壳层中空CuO/Cu_xS_y八面体的形貌和硫化物/氧化物组成发生改变,进而影响其电化学性能。通过XRD,SEM,TEM和XPS对该八面体的形貌结构进行测试分析。测试表明该中空结构具有相互交叉的Cu_xS_y纳米片构成的外壳和位于八面体内部的CuO核层部分。双壳层中空CuO/Cu_xS_y八面体的独特结构和CuO,Cu_xS_y之间的协同效应有利于材料的电化学过程。当硫化时间为6 h时双壳层中空CuO/Cu_xS_y八面体在1 A·g~(-1)的电流密度下具有高达413.6 F·g~(-1)的比电容,并且其在20 A·g~(-1)的电流密度下具有较好的倍率性能和循环稳定性。     

Photocurrent enhancement of d.c. sputtered copper oxide thin films

Copper oxide (CuO) thin films with photocurrent as high as 25 μA/cm² were deposited on conductive glass substrates using d.c. reactive sputtering. This was the highest reported photocurrent for sputteredp- type copper oxide measured in the electrolyte KI. The photocurrent drastically increased up to 25 (μA/cm² as the sputtering pressure and the substrate temperature were increased up to 8.5 mbar and 192°C, respectively. All the synthesized films contained single phase of CuO in this range of pressure and substrate temperature. Variation of the photocurrent, photovoltage, structure and absorbance with deposition conditions were studied in detail.     

溅射沉积CuO薄膜的光学和电学特性

以金属铜为靶材,氧气为反应气体,保持200℃的基底温度不变,通过调节氧氩比(OFR)和反应压强,利用直流反应磁控溅射方法在玻璃衬底上制备了一系列氧化铜薄膜。利用能谱对薄膜材料的元素含量进行测量和分析,结果显示:OFR=1∶1和2∶1时,铜元素和氧元素的含量比约在0.90~0.97的范围内变动。用四探针测试仪对薄膜的电阻率进行测量,用分光光度计测量薄膜的透过率,并用外推法推导出氧化铜薄膜的禁带宽度。利用霍尔效应测试仪对薄膜的电学参数进行测量和分析。     

Growth process of CuO(1 1 1) and Cu2O(0 0 1) thin films on MgO(0 0 1) substrate under metal-mode condition by reactive dc-magnetron sputtering

The growth process of CuO and Cu₂O thin films on MgO(0 0 1) substrates by reactive dc-magnetron sputtering was studied by reflection high-energy electron diffraction (RHEED) and atomic-force microscopy (AFM). The RHEED pattern and AFM image showed that (1) three-dimensional Cu(0 0 1) islands grew on MgO under the nonreactive sputtering condition, (2) CuO(1 1 1) was deposited layer by layer on MgO at 400 °C under the reactive sputtering condition, and (3) the film deposited at 600 °C in the initial growth stage was composed of three-dimensional Cu islands because O₂ gas could not be incorporated into them due to the low sticking coefficient of O₂ on MgO under the reactive sputtering condition. The layer-by-layer CuO(1 1 1) thin-film growth process is discussed from the viewpoint that Cu and oxygen species are supplied in stoichiometry onto the MgO substrate to form CuO thin-film crystals while maintaining minimum interfacial energy between CuO and MgO.     

溅射功率对ZnO：Si透明导电薄膜性能的影响

采用直流磁控溅射法在室温玻璃基片上制备出了掺硅氧化锌（ZnO：Si）透明导电薄膜,研究了溅射功率对ZnO：Si薄膜结构、形貌、光学及电学性能的影响,实验结果表明,溅射功率对ZnO：Si薄膜的生长速率、结晶质量及电学性能有很大影响,而对其光学性能影响不大。实验制备的ZnO：LSi薄膜为六方纤锌矿结构的多晶薄膜,且具有垂直于基片方向的c轴择优取向。当溅射功率从45W增加到105W时,薄膜的晶化程度提高、晶粒尺寸增大,薄膜的电阻率减小;当溅射功率为105W时,薄膜的电阻率达到最小值3．83~104n·cm,其可见光透过率为94．41％。实验制备的ZnO：Si薄膜可以用作薄膜太阳能电池和液晶显示器的透明电极。     

Preparation of highly oriented AlN thin films on glass substrates by helicon plasma sputtering and design of experiments

Aluminum nitride (AlN) thin films were deposited by a helicon plasma sputtering system with a radical cell. We investigated the effects of eight sputtering control factors on the crystal orientation of the films by design of experiments and the analysis of variance (ANOVA) in order to prepare highly oriented AlN thin films on silica glass substrates. Consequently, it was proved statistically that the distance between a target and a substrate, the sputtering pressure and the substrate temperature are significant control factors for the crystal orientation of the films. Especially, the distance is the most important factor of the eight control factors, which has not been reported so far. On the other hand, the effects of the cathode r.f. coil power, the radical cell power, the nitrogen concentration, the sputtering time and the cathode power are not statistically significant. Moreover, a detailed investigation of the dependence of the orientation on the three important control factors was carried out to optimize the sputtering conditions. The full width at half-maximum (FWHM) of the X-ray rocking curve of the film deposited under the optimized sputtering conditions is 2.4° (σ=1.3°). This orientation is the highest in the AlN thin films deposited on amorphous substrates reported to our knowledge.     

CuO/SiO2复合薄膜的微观结构和发光特性分析

采用射频磁控共溅射法在硅衬底上沉积Cu/SiO₂ 复合薄膜,然后在N₂保护下高温退火,再于空气中自然冷却氧化,制备出低维CuO纳米结构,并对其微观结构和光致发光进行研究. 退火温度为1100℃时样品中主晶相为立方晶系的CuO（200）晶面,薄膜样品表面出现纳米线状结构,表面组分主要包括Cu、O元素,冷却氧化形成CuO/SiO₂复合薄膜. 该温度下退火后,光致发光谱中出现紫外光和紫光,这是由于复合薄膜中CuO的导带底到Cu空穴缺陷能级的跃迁导致的.     

磁控溅射制备Al-Cu-Fe薄膜不同溅射时间的生长行为

采用磁控溅射法在硅基材上制备了Al-Cu-Fe薄膜,采用原子力显微镜(AFM)和X射线衍射仪(XRD)研究了不同溅射时间下Al-Cu-Fe薄膜的生长行为。结果表明,随着溅射时间的延长,Al-Cu-Fe薄膜的β晶相的衍射峰半峰宽逐渐减小,而λ晶相的衍射峰半峰宽则逐渐增大。Al-Cu-Fe薄膜的生长依次经历了小岛形核阶段、小岛结合阶段、连续薄膜阶段、晶粒长大阶段等4个阶段。另外,随着溅射时间的延长,Al-Cu-Fe薄膜的粗糙度呈现出先增大后减小的趋势。     

Microstructure analyses of the titanium films formed by the ionized sputtering process

We investigated the microstructure of the Ti-films formed on the (001) single crystal silicon wafers through the ionized sputtering process, and compared the results with those obtained by collimated sputtering. We found that the Ti-films created by ionized sputtering process without the substrate bias show less strong (002) textures than collimated sputtering. The Ti-films created by the ionized sputtering process with the substrate bias did not show any observable strong textures. We also found that the ionized sputtering processed Ti-films show about 4 nm thick amorphous Ti–Si interlayer, which is much thicker than that of the collimated sputtering process. The modifications of the microstructure of Ti-films are attributed to the ion bombardments during the ionized sputtering deposition process.     

溅射气压对TiN薄膜的制备工艺及光学性能的影响

采用直流反应磁控溅射法,在Si（111）基底上制备氮化钛（TiNx）薄膜。研究了溅射沉积过程中腔体气压对TiNx薄膜结构及性能的影响。研究发现：在保持其它工艺参数不变的情况下,改变溅射气压,沉积的TiNx薄膜主要成分是立方相TiN,薄膜的结晶显示出明显的（200）择优取向。在腔体气压为0．5Pa时出现（200）衍射峰最强、择优取向最明显。随着腔体气压的增加,薄膜厚度变小,而衍射峰则呈减弱的趋势。在腔体气压为0．3Pa时,膜层致密均匀,没有大尺寸缺陷且光洁度好,薄膜的结晶度最好,表面也最光滑。在测试波长范围内对光的平均反射率最大（达85％）,可满足光学薄膜质量方面的要求。     

Reactive sputtering of precursors for Cu2ZnSnS4 thin film solar cells

The quaternary semiconductor Cu₂ZnSnS₄ (CZTS) is a possible In-free replacement for Cu(In,Ga)Se₂. Here we present reactive sputtering with the possibility to obtain homogeneous CZTS-precursors with tunable composition and a stoichiometric quantity of sulfur. The precursors can be rapidly annealed to create large grained films to be used in solar cells. The reactive sputtering process is flexible, and morphology, stress and metal and sulfur contents were varied by changing the H₂S/Ar-flow ratio, pressure and substrate temperature. A process curve for the reactive sputtering from CuSn and Zn targets is presented. The Zn-target is shown to switch to compound mode earlier and faster compared to the CuSn-target. The precursors containing a stoichiometric amount of sulfur exhibit columnar grains, have a crystal structure best matching ZnS and give a broad peak, best matching CZTS, in Raman scattering. In comparing process gas flows it is shown that the sulfur content is strongly dependent on the H₂S partial pressure but the total pressures compared in this study have little effect on the precursor properties. Increasing the substrate temperature changes the film composition due to the high vapor pressures of Zn, SnS and S. High substrate temperatures also give slightly denser and increasingly oriented films. The precursors are under compressive stress, which is reduced with higher deposition temperatures.