Fabrication of bowl-like porous WO3 film by colloidal crystal template-assisted electrodeposition method

Large scale of bowl-like porous WO₃ film was successfully fabricated by electrodeposition into two-dimensional (2D) polystyrene (PS) colloidal crystal template. The technological process involved the following steps: colloidal crystal template preparation, potentiostatic electrodeposition of WO₃ into the template, and template removal. 1.5 μm PS spheres were used to prepare the 2D colloidal crystal template by means of spinning on indium-tin-oxide (ITO) glass. A two-electrode cell was used for electrodeposition, in which the anode was graphite and the cathode was PS-coated ITO glass. The electrodeposition solution consisted of 25 mM Na₂WO₄ and 30 % H₂O₂ acidified at pH 1.2. Via electrodeposition, the interstitial space of the densely packed PS colloidal crystal template was filled with WO₃. Bowl-like porous WO₃ film was obtained after the removal of the PS colloidal crystal template by a thermal treatment at 475 °C. Scanning electron microscopic, X-ray diffraction spectra and transmission electron microscopy were performed to analyze and compare bowl-like porous WO₃ film with dense WO₃ film. The homogeneous area of the obtained film was 25 × 15 mm². The template-assisted electrodeposition method was simple and low-cost that can be completed within 30 min.     

Enhanced catalytic activity and ignition characteristics of three-dimensional ordered macroporous FeCo2O4 through controlled synthesis

To improve the combustion performance of solid propellants relies on efficient combustion catalyst with large specific surface area and high density of active sites. In this work, three-dimensional ordered macroporous FeCo₂O₄ (3DOM-FeCo₂O₄) with four different pore diameters was successfully prepared using polymethyl methacrylate (PMMA) colloidal crystals as a template. Differential scanning calorimetry (DSC) study shows that 3DOM-FeCo₂O₄ with a pore diameter of 176 nm has the best catalytic performance on the thermolysis of ammonium perchlorate (AP). The decomposition peak temperature and apparent activation energy were reduced by 116.5 ℃ and 26.1 kJ/mol, respectively. Thermogravimetry/mass spectrometry (TG/MS) was used to analyze the catalytic mechanism. The result indicates that 3DOM-FeCo₂O₄ can accelerate the electron transfer from ClO₄^– to NH₄⁺ to form HClO₄ and NH₃ and the transformation from O₂ to superoxide ion(O₂^–), thus providing active sites for intermediate products of AP and catalyzing the decomposition of AP. Furthermore, the heat release and ignition tests of thermites using 3DOM-FeCo₂O₄ as the oxidant were carried out. The thermite with a pore diameter of 215 nm exhibits higher heat release and better ignition characteristic compared to the thermites with other pore diameters.     

胶晶模板法合成三维有序大孔TiO2

以自然沉积的聚苯乙烯(PS)胶体晶体为模板,一定比例钛酸丁酯、乙醇、醋酸、盐酸和水配制的溶胶溶液为前驱体进行填充,溶胶在PS模板间隙内发生原位凝胶,最后通过煅烧除去模板得到了三维有序大孔(3DOM)TiO2材料.从SEM照片可观察到,3DOMTiO2可以看成是PS模板的逆复制,孔径大小均匀,排列整齐,整体上呈面心立方结构.孔径在280nm左右,收缩率为22%,孔壁填充完全,孔与孔之间由小窗口相连.XRD分析表明,制备的3DOM TiO2孔壁为锐钛矿晶型.     

Preparation and characterization of bowl-like porous ZnO film by electrodeposition using two-dimensional photonic crystal template

A rapid and low-cost method combining electrodeposition with two-dimensional (2D) photonic crystal template technique to prepare large scale bowl-like porous ZnO films is described. The 2D photonic crystal templates were fabricated by self-assembly of monodispersed polystyrene (PS) microspheres on indium-tin-oxide coated glass substrates using spinning coating method. The interstitial spaces among the spheres of the templates were filled with ZnO via electrodeposition from an aqueous solution containing 0.02 M zinc nitrate as electrolyte under a constant potential of ?1.0 V at 65 °C for 10 min. After removal of the PS photonic crystal template, bowl-like porous ZnO film was obtained. The entire process can be accomplished within 30 min. Scanning electron microscopic images showed good homogeneity in morphology, X-ray diffraction spectra demonstrated the wurtzite structure of the obtained ZnO film, and transmission electron microscopy indicated the single-crystallinity of the ZnO. Ultraviolet–visible (UV–vis) spectrophotometer was used to detect the absorption in UV–vis region of the PS template, opal ZnO-PS composite and inverse opal ZnO respectively. Two strong emission bands at 400 and 550 nm were displayed in photoluminescence spectrum.     

Fabrication of free-standing Cu nanorod arrays on Cu disc by template-assisted electrodeposition

Free-standing Cu nanorod arrays on Cu foil have been fabricated by a template-assisted method. Cu nanorods were potentiostatically deposited on mechanically polished Cu foil using anodized aluminum oxide templates as the deposition mask. Three electrolyte systems were compared, including two acid copper sulfate based solutions and one alkaline solution. The most uniform nanorods were achieved in the alkaline electrolyte. The weight gain per unit area after electrodeposition has been used as a direct measure of average length of deposited Cu nanorods. It was found that our control over the uniformity in nanorod length across the array is important in reaching the maximized aspect ratio without aggregation. Through controlling the weight change it was possible to control the aspect ratio of nanorods and to avoid aggregation of nanorods. Our capability to fabricate free-standing Cu nanorod arrays of uniform height with maximized aspect ratio on Cu foil is especially important in applying this nanostructured Cu as a current collector in Li ion batteries.     

快速磁致显色光子晶体膜的制备与性能

采用热聚合的方法制备内嵌有Fe_3O_4@PAA磁性光子晶体纳米链和乙二醇(EG)液滴的聚二甲基硅氧烷(PDMS)光子晶体膜,采用红外光谱、扫描电镜、光学显微镜和光纤光谱仪对产物进行表征和性能分析。结果表明:液滴中光子晶体链能够沿磁场方向自由取向,赋予光子晶体膜结构色亮度可调的特性;光学性能测试结果表明,当磁性光子晶体纳米链链长为5μm,质量浓度为1.77 mg/mL时,制备的光子晶体膜在100 Gs下表现出最优的光学性能,且在2s内光子晶体膜的反射强度基本达到稳定,表现出快速磁致显色的特性。     

气-液界面二元共沉积法制备三维有序大孔SiO2

采用乳液聚合法制备粒径为229nm的单分散聚苯乙烯(PS)微球,以单分散PS微球和粒径为10nm的硅溶胶为原料,采用蒸发自组装法在气-液界面上二元共沉积,制备了大孔SiO2材料。结果表明,当SiO2体积分数为11%时,大孔SiO2材料呈现有序规整的FCC结构,其填充率为42%,收缩率仅为2%。低温N2吸附表明该材料在大孔孔壁上存在6.4nm左右的介孔,是一种具有大孔/介孔复合孔道结构的功能材料。     

SiO2/CdS光子晶体的制备及其光学性能

用化学浴沉淀法(CBD)在SiO2胶体晶体中生长了CdS半导体材料, 并用UV-VIS-NIR光谱仪和荧光光分度计测试了其光学性能.测试结果表明,在SiO2胶体晶体中随着CdS填充量的增加,光子带隙向长波段方向移动且变宽;当发射出的光与基体材料的光子带隙相匹配时,可控制半导体材料的光致发光,同时,可通过控制SiO2胶体颗粒粒经的大小来调节CdS的光致发光性能.     

PS微球的制备及三维胶晶模板的组装和应用

研究了PS微球合成中单体、引发剂和乳化剂浓度以及聚合温度对粒径及分布的影响。采用高速离心沉淀法、恒温加热蒸发诱导法和自然沉降法对单分散PS微球进行了组装,得PS胶体晶体模板,并以其为模板制备了锂离子筛前驱体Li4Mn5O12。用纳米粒度及ZETA电位分析仪、扫描电子显微镜(SEM)、饱和交换容量等表征了材料的粒径及分布、形貌、结构和离子交换性能。结果表明:通过控制反应条件可以在一定范围内制得粒径均一、单分散性好、表面规整光滑的PS微球;PS胶体晶体模板三维有序,排列规整;酸改性后的离子筛前驱体对Li+饱和交换容量为7.49mol/g锂离子筛。     

三维有序大孔间规聚苯乙烯的制备及其功能化

利用通过种子乳液的方法制备的粒径为1100nm的二氧化硅胶体晶为模板,采用配位聚合方式制备了孔径为1000nm的三维有序大孔间规聚苯乙烯材料,进而对其进行了氯甲基孔壁功能化.利用核磁共振、红外光谱、扫描电镜对产物进行了表征分析,结果表明间规结构的聚苯乙烯骨架结构表面引入了氯甲基基团,并且氯甲基化以后依然保持了原有大孔材料孔径均一、结构有序的特点.采用热重-滴定分析测定了相对氯含量为2.3mmol/g.     

Synthesis of multilayer Nano-ZrO2 coated polystyrene spheres on fabrication of three-dimensional ordered macroporous structures

Monodispersed ZrO₂ precursor nanoparticles with a diameter of 25 nm were successfully synthesized by using diglycol as complexing reagent. The kinetic of particle growth as a function of concentration ratio of ZrOCl₂: diglycol was investigated. The as-synthesized ZrO₂ precursor nanoparticles were homogenously coated on the surface of polystyrene particles. Multilayer coating process was implemented by using poly (acrylic acid) (PAA) to modify the surface charges of the coated spheres, which was characterized by zeta-potential, particles size distribution and microstructural observation. The multilayer-coated polystyrene (PS) spheres have been used as templates to produce macroporous materials. Ordered macroporous ZrO₂ materials were obtained after the ZrO₂ precursor nanoparticles coated PS spheres were formed by centrifugation and calcined at 550°C for 3 h. The porous wall thickness could be well controlled by using the multilayer nano-ZrO₂ coated PS spheres with different coating thickness.     

浸渍-涂布法制备In2O3薄膜

以InCl3@4H2O为原料,采用溶胶-凝胶技术、浸渍-涂布法制备了In2O3薄膜.同时对薄膜厚度与In2O3含量、涂布液粘度以及提拉速度等关系进行研究,发现薄膜厚度与涂布液粘度、提拉速度成对数线性关系.膜厚与提拉速度的关系式为t≈v0.62.XRD、IR测试表明经过400℃煅烧,PVA已经完全排除.SEM照片表明薄膜形貌平整、光亮,从而为该种材料制作实用的气敏元件打下了良好的基础.     

Highly ordered three-dimensional macroporous carbon spheres for determination of heavy metal ions

An effective voltammetric method for detection of trace heavy metal ions using chemically modified highly ordered three dimensional macroporous carbon spheres electrode surfaces is described. The highly ordered three dimensional macroporous carbon spheres were prepared by carbonization of glucose in silica crystal bead template, followed by removal of the template. The highly ordered three dimensional macroporous carbon spheres were covalently modified by cysteine, an amino acid with high affinities towards some heavy metals. The materials were characterized by physical adsorption of nitrogen, scanning electron microscopy, and transmission electron microscopy techniques. While the Fourier-transform infrared spectroscopy was used to characterize the functional groups on the surface of carbon spheres. High sensitivity was exhibited when this material was used in electrochemical detection (square wave anodic stripping voltammetry) of heavy metal ions due to the porous structure. And the potential application for simultaneous detection of heavy metal ions was also investigated.     

Preparation and photoluminescence properties of three-dimensionally ordered macroporous ZrO2:Eu3+

Three-dimensionally ordered macroporous (3DOM) ZrO2:Eu3+ (0.5%, 1%, 2% and 5%) were successfully prepared using a polystyrene (PS) colloidal crystal template in combination with a sol-gel method. The structure, morphology, porosity, and optical properties of the materials were well characterized by X-ray diffraction (XRD), Field emission scanning electron micrograph (FESEM), N2 adsorption, and photoluminescence (PL) spectra. The results indicated that the closely packed material exhibited three-dimensional ordering of pores and a strong red (5)D0-->(7)F2 transitions under charge transfer excitation. Strong PL and abundant porosity are of particular interest and give this multifunctional material future potential.     

Fabrication and characterization of ordered macroporous semiconductors CdS by colloidal crystal template

The synthesis and characterization of a highly ordered macroporous CdS with regular arrays of spherical pores comparable to optical wavelengths are discussed. The sample has been successfully fabricated using colloidal crystal of poly (styrene-acrylic) (PSA) spheres as templates. The pore size is tunable in the range of 100-400 nm based on the size of PSA spheres. Transmission electron microscope (TEM) and scanning electron microscope (SEM) show that the exactly three-dimensional structure of the template has been imprinted in the final materials. XRD pattern indicates that the walls of the macroporous material are composed of 4 nm CdS nanoparticles making the absorption spectrum shift blue. The sample was also characterized by Raman spectroscopy and photo luminescent spectra (PL).     

Controllable electrodeposition of ordered carbon nanowalls on Cu(111) substrates

We report the growth of amorphous carbon nanowalls with molten salt electrolytes and a carbonate carbon source at 600 °C on home-made Cu(111) foil as the growth substrate (and cathode). The nanometer thick nanowalls grow preferentially along symmetric slip lines on the Cu(111) surface and their ordered arrangement appears to also be dictated by the electrosynthesis parameters. Computational chemistry suggests that nucleation of carbon growth is favored at the slip lines (atomic steps) of the Cu(111) surface. The electrodeposited carbon structures can be varied by tuning the potential on the electrodes and temperature of the molten salt. The macro, micro, and nanoscale structure of the nanowalls was studied and is reported.     

氧化亚铜薄膜的研究进展

氧化亚铜（Cu2O）具有优越的光电性质，是一种具有广泛用途的材料，而且它的制备方法很多。结合最近的研究进展综述了Cu2O薄膜的制备方法与基本性质，分析了Cu2O薄膜研究开发现状，展望了Cu2O薄膜在太阳能电池应用方面的前景。     

Fabrication of three-dimensional autocloned photonic crystal on sapphire substrate

We applied the laser interference lithography method to form a patterned sapphire substrate (PSS). A three-dimensional photonic crystal was formed by autocloning the PSS with alternate Ta2O5/SiO2 coatings. A high total integrated reflectance (TIR) band was obtained around the 410 to 470?nm wavelength range that matched the emission spectrum of the gallium nitride (GaN) light-emitting diode (LED) for application in manipulating the light extraction of the sapphire-based GaN LED.