由溶胶-凝胶法制备的掺氧化钼的氧化钨薄膜的电致变色性能

钨粉和钼粉在过氧化氢的作用下生成氧化钨和氧化钼的溶液，加入冰乙酸进行酸化，然后在60℃下烘干，用适量的乙醇配得氧化钨和氧化钼母液。用ITO玻璃在该溶液浸泡后拉出并在150℃下烘干1h，便得到掺有氧化钼的氧化钨薄膜。X射线衍射（XRD）显示所得的薄膜为非晶态结构，扫描电镜（SEM）发现整个薄膜的表面较为平滑，但在极其微小的局部仍有裂纹颗粒生成。薄膜的伏安特性显示薄膜对锂离子具有一定的存储能力，其光的透过率测量表明溶胶-凝胶制备的掺有氧化钼的氧化钨薄膜对光具有很好的调节作用。     

WO3@PANI复合材料的制备及其pH传感性能

目的 通过简单快捷的方法制备氧化钨(WO3)/聚苯胺(PANI)复合材料,获得高性能pH传感器。方法 WO3和PANI都是通过原位聚合法制备,在溶液中混合后旋涂在柔性碳基底上。通过扫描电子显微镜、拉曼光谱、XRD等技术对复合材料进行表征,证明复合材料的成功合成并进一步解释其传感增强原理。结果 WO3@PANI可以在pH=2~10内工作,与单体材料相比具有较高的灵敏度(−53.13 mV),较低的滞后度(3.8%)和较快的反应速度(16 s),在10次酸碱循环测试后响应性保持在95%以上,且在12 h的连续测试中可以保持稳定。结论 一方面PANI为WO3提供了导电网络,并将WO3均匀包裹在内;另一方面两者的p-n结构共同作用,使得WO3@PANI的pH传感性能进一步提高。     

The reaction conditions influence on hydrothermal synthesis of boehmite nanorods

Synthesis of boehmite (γ-AlOOH) nanorods were performed by using aluminum nitrate and sodium hydroxide as starting materials in conditions of controlled pH value of reaction mixture, temperature and holding time. X-ray diffraction, transmission electron microscope, high resolution transmission electron microscope, selected area electron diffraction and N₂ adsorption-desorption analysis were used to characterize morphology and structure feathers of the obtained products. The results show that γ-AlOOH nanorods with diameter of 10–30 nm, length of 200–300 nm, aspect ratio of 5–15, regular shape and clear surface were synthesized at 200–220°C for 24 h under pH = 5. The effect of reaction conditions on the morphology of 1D boehmite nanomaterials was discussed.     

WO3纳米薄膜的制备与气致变色特性研究

报道了以钨粉为原料，采用溶胶一凝胶技术和旋转镀膜方法，制备出了气致变色WO3纳米薄膜。采用椭偏仪、X射线衍射仪(XRD)、场发射扫描电子显微镜(FE-SEM)、红外光谱仪以及可见光分光光度计等方法分析了薄膜的特性。研究结果表明热处理使得薄膜致密，折射率增大，厚度减小，薄膜结晶；过氧键消失，WO3微结构发生了变化，共角W-O-W键吸收越来越强，且向高波数方向移动。这些变化归因于热处理导致的WO3颗粒形状、团聚状态的变化以及应变键的产生。WO3纳米薄膜具有很好的气致变色特性，致色与退色态透射率变化超过60％，变色起因于H扩散到WO3薄膜中形成的小极化子吸收。     

带有氧化钨涂层的ITO平面电极在LB系列电解液中的阻抗分析

电致变色实验显示1mol／L六氟磷酸锂与碳酸乙烯酯、碳酸二甲酯、碳酸二乙酯和碳酸甲乙酯所混合形成的电解液（LB）系列是一类非常节能的电致变色电解液，它们能用很小的充电电流（20μA／cm^2）使得氧化钨薄膜获得更长久、更好的变色性．研究氧化钨薄膜在LB系列电解液中的交流阻抗特性，有助于更好地理解氧化钨薄膜的变色性能．文中研究了带有氧化钨薄膜层的ITO平面电极处于LB系列电解液中的阻抗谱，分别得出了氧化钨薄膜和ITO电极的等效电路；测算出氧化薄膜的常相位角元件、薄膜电阻、韦伯电阻以及与ITO电极有关的电双层电容和电极电荷转移电阻．证实了LB315是性能优良的电解液．     

新型低压WO3基压敏电阻掺杂及制备条件研究

研究了Ｃｏ２Ｏ３掺杂剂工艺及条件等对低压ＷＯ３基压敏电阻性能的影响,在保持ＭｎＯ２及Ｎａ２ＣＯ３含量不变的前提下,我们发现,对于ＷＯ３－ＭｎＯ２－Ｎａ２ＣＯ３系列,掺入Ａｌ２Ｏ３可以明显改善其电化学稳定,但同时也失去了非线性,而Ｃｏ２Ｏ３的掺入可以明显提高非线性,以１％（摩尔分数）的Ｃｏ２Ｏ３含量为最好,其α值约为５．５（从Ｕ１ｍＡ到Ｕ０．ｍＡ）击穿场强小于１０Ｖ／ｍｍ。最高烧结温度应不低于１１０     

Well-designed WO3/Activated carbon composite for Rhodamine B Removal: Synthesis,characterization, and modeling using response surface methodology

This study focuses on the preparation of WO₃ oxide nanoparticle/Activated carbon composite (WO₃/AC) for Rhodamine B (RhB) adsorption. The prepared samples were characterized using X-Ray Energy Dispersive Spectroscopy (EDS) and Scanning Electron Microscopy (SEM), Brunauer–Emmett–Teller surface area (BET), Raman Spectroscopy and Thermogravimetric analyses (ATG-ATD). Adsorption experiments of RhB onto WO₃/AC were carried out in a batch reactor and different operational parameters were investigated. The RhB adsorption process was well fitted by pseudo-second-order kinetic and Langmuir isotherm models (1666.67mg.g^?1). Moreover, the values of thermodynamic parameters indicate the spontaneous, endothermic and physisorption adsorption nature. Finally, adsorption mechanism was proposed on the basis Raman analyses before and after adsorption.     

Ti掺杂及退火处理对水热合成WO_3纳米晶粒结构及气敏性能的影响

采用水热法制备了不同掺杂浓度的WO3∶Ti纳米晶粒,并在350℃下退火1 h。采用SEM、XRD表征了材料的形貌与结构,并测试了用退火前后合成材料制成的薄膜气敏传感器件在200℃下对NO2的气敏性能。结果表明,Ti掺杂可以有效抑制WO3晶粒的生长,减小晶粒尺寸;退火处理使材料的晶相发生了改变,晶粒尺寸进一步减小,晶粒分散性变好。薄膜传感器件的测试结果显示,适量Ti掺杂和退火处理均可提高器件对NO2的灵敏度,退火后Ti掺杂2%样品制成的器件的灵敏度最大,其值达到了15.38,响应恢复时间分别为2.2和1.5 min,且具有良好的可重复性和稳定性。     

Selective synthesis of copper nanoplates and nanowires via a surfactant-assisted hydrothermal process

A facile solution-phase process has been demonstrated for the selective preparation of single-crystalline Cu nanoplates and nanowires by reducing Cu⁺ with ascorbic acid (VC) in the presence of cetyltrimethylammonium bromide (CTAB) or cetyltrimethylammonium chloride (CTAC). To study the formation process of nanoplates and nanowires, samples obtained at various stages of the growth process were studied by TEM and XRD. The possible mechanism was discussed to elucidate the formation of different morphologies of Cu nanostructures. UV–vis spectra of the Cu nanoplates and nanowires were recorded to investigate their optical properties, which indicated that the as-prepared Cu nanostructures exhibited morphology-dependent optical property.     

Synthesis of Sb2O3 nanorods under hydrothermal conditions

Sb₂O₃ nanorods were successfully prepared via a mild hydrothermal route based on the reactions between SbCl₃ and NH₃·H₂O in aqueous solution at 120-180 °C for 12 h. The as-prepared Sb₂O₃ nanorods were characterized by X-ray diffraction (XRD), transmission electronic microscopy (TEM), and X-ray photoelctron spectroscopy (XPS). Results showed that NH₃·H₂O played a significant role in the formation of Sb₂O₃ nanorods. The presence of NH₃·H₂O could greatly favor the reaction progress toward the right-hand side and led to the orientation growth of Sb₂O₃ nanorods. A possible mechanism for the formation of Sb₂O₃ nanocrystallites was discussed.     

Influence of deposition conditions on the morphology and phase of tungsten oxide nanorods synthesized by thermal oxidation

When synthesizing tungsten oxide nanorods using thermal oxidation,the deposition conditions play an important role in the morphology and phase structure.The evaporation voltage greatly influences the a...     

Interfacing Photosynthetic Membrane Protein with Mesoporous WO3 Photoelectrode for Solar Water Oxidation

Photosynthetic biocatalysts are emerging as a new class of materials, with their sophisticated and intricate structure, which promise improved remarkable quantum efficiency compared to conventional inorganic materials in artificial photosynthesis. To break the limitation of efficiency, the construction of bioconjugated photo‐electrochemical conversion devices has garnered substantial interest and stood at the frontier of the multidisciplinary research between biology and chemistry. Herein, a biohybrid photoanode of a photosynthetic membrane protein (Photosystem II (PS II)), extracted from fresh spinach entrapped on mesoporous WO₃ film, is fabricated on fluorine‐doped tin oxide. The PS II membrane proteins are observed to communicate with the WO₃ electrode in the absence of any soluble redox mediators and sacrificial reagents under the visible light of the solar spectrum, even to 700 nm. The biohybrid electrode undergoes electron transfer and generates a significantly enhanced photocurrent compared to previously reported PS II‐based photoanodes with carbon nanostructures or other semiconductor substrates for solar water oxidation. The maximum incident photon‐to‐current conversion efficiency reaches 15.24% at 400 nm in the visible light region. This work provides some insights and possibilities into the efficient assembly of a future solar energy conversion system based on visible‐light‐responsive semiconductors and photosynthetic proteins.     

双氧水和退火温度对WO_3薄膜光电化学性质的影响

以WO3粉体合成的W络合离子作为前驱液,超声喷雾热裂解法（USP）制备出WO_3薄膜,研究前驱液中H_2O_2添加量、薄膜沉积温度和薄膜退火温度对WO_3薄膜光电化学性能的影响,利用XRD、UV-vis和光电流光谱（IPCE）等对薄膜进行表征,实验结果表明,USP制备的WO_3薄膜为单斜相且沿（200）晶面优势生长;前驱液中双氧水量的增加导致WO_3薄膜禁带宽度（E_g）增加;薄膜的平带电位（Vfb）在-0.27~-0.05V之间（vs.SCE,pH=7）,且掺杂浓度随退火温度升高而降低;在0.1M的Na_2SO_3溶液中,薄膜的IPCE随退火温度升高而降低,随H_2O_2量的减小IPCE增高。     

水热法制备MoO_2纳米棒的自组装生长机理研究

水热条件下,以双氧水和钼粉制备的过氧钼酸溶胶为钼源,乙醇为还原剂制备得到Mo O2纳米棒。利用X射线衍射(XRD)、扫描电子显微镜(SEM)以及场发射高分辨透射电子显微镜(HRTEM)对产物的结构与形貌进行表征。结果表明,水热反应初期过氧钼酸溶胶首先生成Mo3纳米带,随后在还原剂的作用下,纳米带逐渐劈裂成扇形Mo8O23,最后在乙醇的还原下,扇形Mo8O23纳米片进一步劈裂形成结晶良好的Mo O2纳米棒。     

The kinetics of the hydrothermal growth of ZnO nanostructures

The immersion of a material, seeded with ZnO nanoparticles, in an aqueous solution of Zn(NO₃)₂ and hexamethylenetetramine (HMT) at 90 °C yields an extended array of one-dimensional ZnO on the substrate surface. The structure of the ZnO evolves with reaction time. Initially nanorods are formed. At longer times the rods are tipped with nanotubes. Here we report a series of experiments in which both the composition of the reaction solution; concentrations of H⁺, Zn²⁺ and HMT; and the structure of ZnO deposited on the substrate are monitored as a function of reaction time. It was found that the change from ZnO rod to tube growth arises when the solution composition is such that it is no longer thermodynamically favorable to precipitate Zn(OH)₂.     

Selective growth of ZnO nanorods for gas sensors using ink-jet printing and hydrothermal processes

Selective growth of ZnO nanorod arrays with well-defined areas was developed to fabricate the NO₂ gas sensor. The seed solution was ink-jet printed on the interdigitated electrodes. Then, vertically aligned ZnO nanorods were grown on the patterned seed layer by the hydrothermal approach. The influences of seed-solution properties and the ink-jet printing parameters on the printing performance and the morphology of the nanorods were studied. Round micropattern (diameter: 650 μm) of ZnO nanorod arrays is demonstrated. The dimensions and positions of the nanorod arrays can be controlled by changing the printed seed pattern. The effects of nanorod structure and nanorod size on the gas-sensing capability of ZnO nanorod gas sensors were demonstrated. Due to the high surface-to-volume ratios of the nanorod-array structure, the ZnO nanorod gas sensor can respond to 750 ppb NO₂ at 100 °C. The sensors without baking treatment exhibit the typical response of a p-type semiconductor. However, only the response of n-type semiconductor oxides was observed after the annealing treatment at 150 °C for 2 h.     

WO3-Assisted Synergetic Effect Catalyzes Efficient and CO-Tolerant Hydrogen Oxidation for PEMFCs

Developing anode catalysts with substantially enhanced activity for hydrogen oxidation reaction (HOR) and CO tolerance performance is of great importance for the commercial applications of proton exchange membrane fuel cells (PEMFCs). Herein, an excellent CO-tolerant catalyst (Pd-WO₃/C) has been fabricated by loading Pd nanoparticles on WO₃ via an immersion-reduction route. A remarkably high power density of 1.33 W cm⁻² at 80 °C is obtained by using the optimized 3Pd-WO₃/C as the anode catalyst of PEMFCs, and the moderately reduced power density (73% remained) in CO/H₂ mixed gas can quickly recover after removal of CO-contamination from hydrogen fuel, which is not possible by using Pt/C or Pd/C as anode catalyst. The prominent HOR activity of 3Pd-WO₃/C is attributed to the optimized interfacial electron interaction, in which the activated H* adsorbed on Pd species can be effectively transferred to WO₃ species through hydrogen spillover effect and then oxidized through the H species insert/output effect during the formation of H_xWO₃ in acid electrolyte. More importantly, a novel synergetic catalytic mechanism about excellent CO tolerance is proposed, in which Pd and WO₃ respectively absorbs/activates CO and H₂O, thus achieving the CO electrooxidation and re-exposure of Pd active sites for CO-tolerant HOR.     

水热合成不同形貌的纳米三氧化钨及形成机理探讨

以钨酸钠和盐酸为原料,柠檬酸、酒石酸、对硝基苯甲酸、对氨基苯甲酸和尿素为辅助试剂,在一定温度下通过水热法制备出不同形貌的纳米三氧化钨。对所得产物进行X射线衍射(XRD)、透射电镜(TEM)和扫描电镜(SEM)的分析。结果表明:使用不同的助剂将制备不同形貌的纳米三氧化钨,推测可溶性有机酸在水热反应中起到"软模板剂"的作用,尿素在高压下产生的气体有助于增强产物的分散性,得到尺寸均匀的纳米粉体。     

The growth and the ultraviolet photoresponse properties of the horizontal growth ZnO nanorods

The horizontal ZnO nanorods (NRs) were grown by using a low temperature hydrothermal method between the lithographic ZnO interdigital electrodes. In order to horizontally grow the ZnO nanorods, the vertical growth was restrained by coating with the photoresist on the surface nucleation sites. By controlling the distance between the electrodes, only the electrodes for an interval of 7 μm can be connected by the horizontal nanorods to form device. The electrical property of the device was measured. The detector showed a narrow ultraviolet photoresponse with a response peak at 379 nm, which was according with the peak of the photoluminescence. The mechanism of photoresponse was discussed.