光致变色纳米WO3薄膜研究进展

介绍了纳米WO3薄膜的光致变色机理,并对WO3薄膜的各种制备方法进行了分析比较.概述了WO3薄膜的各种表征手段和近年来国内外的研究现状等,并对其未来发展趋势进行展望.     

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。     

纳米WO3薄膜

综述了纳米WO3薄膜的制备、表征及其在电致变色、气敏材料、共催化剂等方面的应用和作用原理.     

SiO2纳米复合稳定WO3薄膜气致变色特性研究

以钨粉为主要原料,采用过氧化法及提拉技术制备WO3薄膜,通过SiO2纳米颗粒复合改性提高了WO3薄膜的气致变色稳定性.测试并研究了SiO2复合掺杂对溶胶颗粒分布、气致变色稳定性等的影响,通过测试薄膜循环中红外振动吸收的演变,深入研究了SiO2纳米复合对WO3薄膜气致变色性能影响的内在机制.研究结果表明,SiO2的掺杂抑制了WO3薄膜内的共角聚合,将薄膜的致/褪色循环次数由20次提高到500次以上,WO3-SiO2复合薄膜的稳定网络结构是提高其气致变色循环稳定性的主要原因.     

WO3薄膜的制备及气敏特性研究进展

WO3薄膜是一种智能材料，在电致变色、共催化和气敏性方面具有广阔的应用前景。综述了WO3薄膜材料的制备方法及现状，并对其优缺点进行了评价。介绍了气敏性方面的应用和机理，说明了不同掺杂对气敏的影响；并对今后的发展方向提出了一些看法。     

WO3电致变色薄膜的研究进展

过渡金属氧化物WO3因其优异的电致变色性能而受到广泛的应用。根据近几年来国内外文献,针对有关WO3薄膜的制备方法做了综述性的介绍,概述了双注入模型这种目前广为接受的WO3薄膜的变色机理,着重陈述了薄膜光调制幅度和非晶态对于WO3薄膜的电致变色性能的重大意义。文章同时列举WO3薄膜在实际生活中的一些应用,说明由于变色响应时间过长和工作稳定性不足导致其进一步应用受到较大限制的现状。最后探讨了WO3薄膜未来的研究方向,经过分析认为以WO、掺杂有机聚合物而制备出复合材料薄膜是WO3薄膜今后一段时间的主要发展方向。     

Pt／WO3纳米薄膜的氢敏特性

用溶胶-凝胶法和磁控溅射法相结合制备了催化剂Pt掺杂的WO3纳米薄膜,通过改变氢气的体积分数、催化剂Pt的含量及热处理温度等实验因素,对Pt／WO3薄膜的氢致变色性能进行了测试;并利用X射线光电子能谱仪（XPS）分析了薄膜的氢敏机理。实验结果表明：先用溶胶-凝胶法制得WO3薄膜,然后再用磁控溅射法在该WO3薄膜上溅射掺杂5％的Pt,制得Pt／WO3双层纳米薄膜,经100℃热处理后,可以获得性能稳定且具有良好氢敏特性的优质薄膜;薄膜能检测的氢气浓度低至0．008％;XPS分析表明,W^5＋与W^6＋之间的转换是引起WO3薄膜氢致变色现象的主要原因。     

纳米晶WO_3电致变色特性(英文)

采用射频反应溅射制备了纳米晶WO3薄膜.基于Berg理论建立了WO3射频反应溅射模型,并分析工艺参数对滞回曲线的影响,基于研究了抽速、基片温度、馈入功率、靶片间距和溅射靶等离子体溅射面积的影响.提出了一种新的消除滞回曲线的制备纳米晶WO3薄膜的方法和优化的工艺参数.论文制备了性能良好的电致变色纳米晶WO3薄膜.分别用环境扫描电镜(ESEM)、X射线光电子能谱(XPS),X射线衍射(XRD)和分光光度计测试了该薄膜,该薄膜在可见光波段,不变色时的透光率大于95%,变色后为65%.纳米晶WO3薄膜的晶粒尺寸在40纳米左右,其高比表面积和缺陷态为电致变色的例子扩散提供了通道.     

纳米掺钯WO3薄膜及气致变色性能研究

以钨粉和双氧水为原料,采用溶胶-凝胶技术结合提拉镀膜法,制备了纳米结构掺钯气致变色WO3薄膜;分析了薄膜的折射率、厚度、结晶度、红外特性和表面形貌随温度变化特性;研究了薄膜的气致变色性能。研究结果表明,纳米掺钯气致变色WO3薄膜有着良好的气致变色特性。重点讨论了薄膜结构、薄膜水含量以及薄膜钯含量对薄膜变色效率的影响。     

纳米WO_3的结构、制备及应用前景

在国内外最新研究文献的基础上总结了纳米WO3的多种制备方法及各自优缺点,其中详细介绍了溶-胶凝胶法、溅射法、化学气相沉积法、蒸发法等,并对纳米WO3的潜在应用进行了介绍,并展望了其发展方向.     

WO3基纳米材料的可控合成及其功能化应用

WO_3基纳米材料具有光催化降解、光解水、电致变色、热致变色和光致变色等特性,在光催化剂、新能源利用、智能窗口、传感器和平板显示器等领域有广阔的应用前景。详细介绍了喷雾干燥法、溶胶-凝胶法、水热法和模板法在制备WO_3基纳米材料方面的研究进展,同时分析了各制备方法目前所存在的问题。综述了WO_3基纳米材料近年来在催化降解、污染物吸附、光解水制氢、电致变色等方面应用的研究现状,分析了其未来的应用和发展前景。     

WO3薄膜气敏光学传感特性研究

WO3薄膜是良好的光学气敏传感器材料.采用溶胶凝胶法制备了WO3掺杂薄膜,对样品在不同浓度氢气气氛中的气敏光学性质、敏感度及响应时间进行了测试、分析和计算,并结合光传输理论给出了气敏薄膜的光学变化机制,理论分析与实验结论吻合.     

NH3 sensing characteristics of nano-WO3 thin films deposited on porous silicon

The NH3 sensing characteristics of nano-tungsten trioxide (WO3) thin films deposited on porous silicon (PS) were investigated in the present study. Porous silicon layer was first prepared by electrochemical etching in an HF-based solution on a p(+)-type silicon substrate. Then, WO3 nano-films were deposited on the porous silicon layer by DC magnetron sputtering. Pt electrodes were deposited on the top surface of the WO3 films to obtain the WO3/PS gas sensor. The WO3 films deposited on PS were characterized by SEM, XRD and XPS. The NH3 sensing characteristics for WO3/PS gas sensor were tested at room temperature and 50 degrees C. The results showed that the NH3 sensing characteristics of WO3/PS were superior to WO3/Al2O3 at room temperature. The sensing mechanism of the nano-WO3 thin films based on PS was also discussed.     

Recent Progress of Three-dimensionally Ordered Macroporous (3DOM) Materials in Photocatalytic Applications: A Review

In recent years, three-dimensionally ordered macroporous (3DOM) materials have attracted tremendous interest in the field of photocatalysis due to the periodic spatial structure and unique physicochemical properties of 3DOM catalysts. In this review, the fundamentals and principles of 3DOM photocatalysts are briefly introduced, including the overview of 3DOM materials, the photocatalytic principles based on 3DOM materials, and the advantages of 3DOM materials in photocatalysis. The preparation methods of 3DOM materials are also presented. The structure and properties of 3DOM materials and their effects on photocatalytic performance are briefly summarized. More importantly, 3DOM materials, as a supported catalyst, are extensively employed to combine with various common materials, including metal nanoparticles, metal oxides, metal sulfides, and carbon materials, to enhance photocatalytic performance. Finally, the prospects and challenges for the development of 3DOM materials in the field of photocatalysis are presented.     

Recent progress on elaboration of undoped and doped Y2O3, Gd2O3 rare-earth nano-oxide

Some selected materials with small sizes in the nanometer region are reviewed. Different methods for synthesis of nanoscale materials are classified and discussed. Basic prerequisites for successful use of the materials for nanotechnology application are their synthesis with specific and homogeneous composition and geometry. This review summarizes recent results on nanoscale materials containing optically active lanthanide ion especially focused on Y2O3 and Gd2O3 oxide.     

锂离子电池正极材料LiCo1/3Ni1/3Mn1/3O2的研究进展

综述了近几年锂离子电池正极材料层状三元过渡金属氧化物LiCoxNiyMn1-x-yO2的研究进展，重点讨论了综合性能优异的LiCo1/3Ni1/3Mn1/3O2的电化学性能、结构、制备方法以及存在的不足，LiCo1/3Ni1/3Mn1/3O2与其它商业化正极材料相比具有高容量、热稳定性好、高倍率放电等诸多优异的性能，若能解决循环、存放等问题，将有望成为新一代锂离子电池正极材料。     

Progress in 3D Printing of Carbon Materials for Energy‐Related Applications

The additive‐manufacturing (AM) technique, known as three‐dimensional (3D) printing, has attracted much attention in industry and academia in recent years. 3D printing has been developed for a variety of applications. Printable inks are the most important component for 3D printing, and are related to the materials, the printing method, and the structures of the final 3D‐printed products. Carbon materials, due to their good chemical stability and versatile nanostructure, have been widely used in 3D printing for different applications. Good inks are mainly based on volatile solutions having carbon materials as fillers such as graphene oxide (GO), carbon nanotubes (CNT), carbon blacks, and solvent, as well as polymers and other additives. Studies of carbon materials in 3D printing, especially GO‐based materials, have been extensively reported for energy‐related applications. In these circumstances, understanding the very recent developments of 3D‐printed carbon materials and their extended applications to address energy‐related challenges and bring new concepts for material designs are becoming urgent and important. Here, recent developments in 3D printing of emerging devices for energy‐related applications are reviewed, including energy‐storage applications, electronic circuits, and thermal‐energy applications at high temperature. To close, a conclusion and outlook are provided, pointing out future designs and developments of 3D‐printing technology based on carbon materials for energy‐related applications and beyond.     

Characterizing the feasibility of processing wet granular materials to improve rheology for 3D printing

Rheological measurements and extrusion tests are used to evaluate the viability of high mass fraction (80% solids content) wet granular materials for extrusion-based 3D printing. Such materials have diverse applications from making dense, strong ceramic custom parts to 3D printing uniquely shaped energetic materials. Traditionally, 3D-printed colloidal materials use much lower mass fraction inks, and hence, those technologies will not work for systems requiring higher mass fraction solids content. These wet granular materials are highly non-Newtonian presenting non-homogenous flows, shear thinning, yield stress, and high elasticity. Such behaviors improve some aspects of print quality, but make printing very difficult. In this work, the relationship between the rheological behavior of wet granular materials and the processing parameters that are necessary for successfully extruding these materials for printing is examined. In the future, such characterizations will provide key indicators on how to alter printer design/operating conditions and adjust material behavior in order to improve printability. This study is a fundamental first step to successfully developing 3D printing technology of wet granular materials.