铁掺杂二氧化钛空心球的制备及性能

以TiF₄为钛源、九水合硝酸铁为掺杂前体,采用水热法制备铁掺杂的TiO₂空心微球。采用SEM、TEM、XRD、BET、XPS等技术对样品的形貌、结构、晶型、比表面积、元素组成等进行表征,以亚甲基蓝（MB）的光催化降解为目标反应,评价其光催化活性。结果表明,160℃下水热反应生成的纳米TiO₂空心微球晶型为锐钛矿,少量掺铁并不影响微球的形貌及晶体结构。光催化实验表明,160℃下水热反应12 h生成的TiO₂空心微球样品均匀性好、光催化活性最佳;铁掺杂能显著提高TiO₂空心微球的催化活性,当铁钛比为1.5:100时,所得样品粒径最小,比表面积最大,光催化活性最高。     

Bi-component MnO/ZnO hollow microspheres embedded in reduced graphene oxide as electrode materials for enhanced lithium storage

Novel composite of bi-component MnO/ZnO (denoted as MZO) hollow microspheres embedded in reduced graphene oxide (RGO) as a high performance electrode material for Lithium ion batteries (LIBs) is prepared via one-pot hydrothermal method and subsequent annealing. The structures and morphologies of as-prepared hybrid materials are characterized by X-ray diffraction, scanning electron microscopy, Raman spectra, FTIR and transmission electron microscopy. The results reveal that the MZO hollow microspheres with nanometer-sized building blocks are well dispersed in the RGO support. The electrochemical tests show that the hybrid material has a reversible capacity of 660 mAh/g at a current density of 100 mA/g with a coulombic efficiency of 98% after 100 cycles. Besides, a specific capacity of about 207 mAh/g is retained even at a current density as high as 1600 mA/g, exhibiting high reversibility and good capacity retention. Our results suggest that the composite of bi-component MZO hollow microspheres embedded in RGO will be promising electrode materials for low-cost, environmentally friendly and high-performance LIBs.     

Ag/TiO2空心微球的制备及光催化杀菌性能的研究

采用一步水热法,以NH4HF2作为形貌控制剂、反应温度为200℃、反应时间为12h,制备锐钛矿型TiO2空心微球,并通过紫外光还原法在TiO2表面沉积单质银.采用SEM、TEM、XRD以及EDS对样品进行表征,以罗丹明B作为模拟污染物表征样品的催化性能.锐钛矿型TiO2空心微球在40 min时降解率达93％,载银二氧化钛复合材料的光催化性能优于纯二氧化钛,当载银量达到2.5％时,光催化活性最佳,在30 min时降解率为98％.采用抑菌圈法表征其杀菌性能,其抑菌圈的直径达16 mm.     

Facile fabrication of porous hollow CeO2 microspheres using polystyrene spheres as templates

Porous hollow CeO₂ microspheres were fabricated using negative-charged PS microspheres as templates by a facile method. The hollow CeO₂ microspheres were characterized by X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and N₂ adsorption?Cdesorption. The results showed that the as-synthesized hollow CeO₂ microspheres are well monodisperse and uniform in size. The porous shells of hollow microspheres are relatively rough and composed of tiny nanoparticles. The external diameter, internal diameter, and shell thickness of hollow CeO₂ microspheres are about 190, 160, and 15?nm, respectively. A possible mechanism for the formation of hollow CeO₂ spheres was also discussed.     

EDTA-assisted template-free synthesis and improved photocatalytic activity of homogeneous ZnSe hollow microspheres

Homogeneous ZnSe hollow microspheres were synthesized on a large scale through an EDTA-assisted mixed solvothermal strategy without any surfactants and templates. The as-synthesized ZnSe microspheres were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and UV–vis absorption spectroscopy. The results of photodegradation of methylene blue (MB) indicate that the hollow microspheres exhibit a visible-light-responsive photocatalytic behavior. As compared with the bulk ZnSe, the photocatalytic efficiency for the hollow microspheres was enhanced remarkably, which might be related with the hollow aggregates of ZnSe nanocrystallites.     

Attachment of ZnO nanoparticles onto layered double hydroxides microspheres for high performance photocatalysis

In this study, ZnO nanoparticles were successfully deposited on the surface of ZnMgAl–CO₃–LDHs microspheres to form ZnO/ZnMgAl–CO₃–LDHs heterojunction photocatalysts by coprecipitation process. The samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and UV–vis diffuse reflectance spectroscopy. The results show that ZnO nanoparticles with diameters about 10–80 nm are tightly grown on the nanosheets of the ZnMgAl–CO₃–LDHs microspheres. Compared with the pristine ZnMgAl–CO₃–LDHs microspheres and pure ZnO, the photocatalytic activity of the heterojunction ZnO/ZnMgAl–CO₃–LDHs photocatalyst is significantly enhanced towards the degradation of phenol under UV light irradiation. The enhancement of the photocatalytic activity of the heterojunction catalysts can be ascribed to their improved light absorption property and the lower recombination rate of the photoexcited electrons and holes during the photocatalytic reaction. The optimal molar ratio of ZnO/ZnMgAl–CO₃–LDHs for the photocatalysis is 3. The heterojunction photocatalyst ZnO/ZnMgAl–CO₃–LDHs may be a promising photocatalyst for future application in water treatment due to its excellent performance in degradation of phenol.     

Self-assembly synthesis of ZnO with adjustable morphologies and their photocatalytic performance

ZnO with hierarchical microspheres and hexagonal prisms structures were successfully synthesized by hydrothermal microemulsion route. Based on X-ray diffraction and scanning electron microscopy observation of the products at the different reaction time periods, the formation mechanism of three-dimensional hierarchical ZnO microspheres was proposed. Ultraviolet and visible diffuse reflectance spectra indicated that as-synthesized ZnO microspheres had enhanced absorption in both ultraviolet and visible light areas. The photocatalytic activities of as-synthesized products were evaluated by monitoring the degradation of methylene blue solution. Due to the synergistic effects of the high crystallization and special hierarchical structure, the hierarchical ZnO microsphere exhibited the highest photocatalytic activity.     

A novel mercury-media route to synthesize ZnO hollow microspheres

Zinc oxide (ZnO) hollow microspheres were prepared by templates of surfactant spheres in mercury-media for the first time. Field emission scan electron microscope (FESEM), X-ray diffraction (XRD), infrared spectra (IR) and N₂ adsorption–desorption analysis were used to characterize morphologies and structure features of the products. The obtained ZnO hollow microspheres are amorphous, 1–3 μm in diameter and 70–140 nm in wall thickness. After heat treatment at 500 °C for 2 h, the amorphous ZnO hollow spheres transform to hexagonal wurtzite structure ZnO, and retain hollow sphere morphologies. During the growth of ZnO hollow microspheres, Zn is oxidized at mercury/air interface and the formed ZnO nanoparticles are assembled on the surface of surfactant spheres. PEG plays an important role for the synthesis of ZnO hollow microspheres.     

Monodisperse temperature-responsive hollow polymer microspheres: Synthesis, characterization and biological application

Temperature-responsive hollow poly(N-isopropylacrylamide) (PNIPAAm) microspheres were prepared by a two-stage distillation precipitation polymerization to afford a core-shell microspheres with subsequent removal of poly(methacrylic acid) (PMAA) core. PMAA@PNIPAAm core-shell microspheres were synthesized by the second-stage polymerization of NIPAAm in the presence of PMAA as core with N,N′-methylenebisacrylamide as crosslinker in acetonitrile, in which the hydrogen-bonding interaction between the carboxylic acid group of PMAA core and the amide group of NIPAAm as well as MBAAm played a key role to form the core-shell microspheres. The hollow PNIPAAm microspheres with different thicknesses, which were controlled by the monomer loading level and the crosslinking degree, were developed after the removal of PMAA core. The loading and controlled-release behavior of the drug on the hollow PNIPAAm microspheres was investigated with doxorubicin hydrochloride. The core-shell and hollow microspheres were characterized with transmission electron microscopy, scanning electron microscopy, dynamic light scattering, static light scattering, X-ray photoelectron spectroscopy, elemental analysis, and FT-IR spectra.     

含锰铁氧化物磁性中空微球的制备与性能表征

用沉积表面反应法制备了以聚苯乙烯为核、Mn-Fe氧化物为壳的磁性核-壳微球. 考察了锰含量对核-壳球磁性的影响,分别采用烧结法和溶剂萃取法去除核-壳球内的聚苯乙烯以制取中空微球. 讨论了烧结温度与所形成的中空微球比表面积的关系,考察了溶剂萃取法去除聚苯乙烯的效果,比较了两者所形成的中空微球的性能. 结果表明,烧结法所得微球性能优于溶剂萃取法所得微球. 探讨了烧结法形成中空磁性球的最佳条件,在400℃下煅烧核-壳微球可以得到饱和磁化强度为68.66 emu/g、比表面积为27.8438 m2/g的含锰铁氧化物磁性中空微球.     

Construction of Z-scheme type CdS–Au–TiO2 hollow nanorod arrays with enhanced photocatalytic activity

The Z-scheme type CdS–Au–TiO₂ hollow nanorod arrays have been constructed on glass substrates by following these simple steps: firstly, highly ordered TiO₂ hollow nanorod arrays (THNAs) were synthesized by liquid phase deposition (LPD) using ZnO nanorod arrays as templates; then both Au core and CdS shell nanoparticles were achieved on the THNAs by in situ photodeposition. The prepared three-component films were characterized by field-emission scanning electron microscopy (FSEM), high-resolution transmission electron microscope (HRTEM), Raman scattering and ultraviolet–visible absorption spectrum. The results showed that Au–CdS core–shell nanoparticles were well dispersed on wall of anatase THNAs from top to bottom. The three-component nanojunction system was evaluated for their photocatalytic activity through the degradation of methylene blue (MB) in aqueous solution. It was found that the CdS–Au–TiO₂ three-component hollow nanorod arrays exhibited significantly enhanced photocatalytic activity compared with single (THNAs) and two components (Au-THNAs or CdS-THNAs) systems. Reasons for this enhanced photocatalytic activity were revealed by photoluminescence (PL) results of our samples.     

Synthesis of hierarchical porous ZnO microspheres and its photocatalytic deNOx activity

Hierarchical porous metal oxide nanostructures have currently attracted much interest because their unique structures with large surface area, high porosity and low density are greatly valuable for functional applications in catalysis, biological engineering and photoelectronics device. Herein, hierarchical porous ZnO microspheres were fabricated by a facile hydrothermal method with subsequent calcination. The sample morphology has been characterized by scanning electron microscopy and transmission electron microscopy. The powder X-ray diffraction has also been used to determine the crystalline structure of the synthesized materials. The effect of calcination temperature on the crystalline structure of synthesized nanostructures has been systematically investigated. The photocatalytic activities of the obtained samples have been evaluated by means of photocatalytic decomposition of nitrogen monoxide (NO).     

Synthesis, surface modification and photocatalytic property of ZnO nanoparticles

ZnO nanoparticles were synthesized by calcination of precursor prepared by the precipitation method. Polystyrene was grafted onto the surface of ZnO nanoparticles to improve the dispersion of the particles and to reduce their photocatalytic activity. The obtained particles were characterized by Fourier transform infrared spectroscopy, X-ray powder diffraction, and transmission electron microscopy. The photocatalytic activity of bare and modified ZnO nanoparticles was studied. The influence of surface modification on the photocatalytic degradation of methyl orange has been analyzed. The composition of residual solution was determined through high performance liquid chromatography. Experimental results show that well dispersed ZnO nanoparticles were obtained after surface modification. ZnO nanoparticles possess high photocatalytic activity, whereas the photocatalytic activity can be significantly reduced when polystyrene was grafted onto the particle surface.     

Synthesis of N-doped ZnO nanoparticles with improved photocatalytical activity

ZnO nanoparticles with diameters of 20–50 nm were initially prepared by solvothermal route using ZnCl₂ and ethylene glycol as raw materials. With the as-prepared ZnO nanoparticles as precursor and melamine as N source, N-doped ZnO nanoparticles were then successfully obtained by a simple, efficient, and environmentally-friendly vacuum atmosphere method. Both the undoped and N-doped ZnO nanoparticles have been characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectrometry. The N-doped ZnO nanoparticles were found to exhibit obviously improved photocatalytic performance for the degradation of methyl orange under simulated daylight irradiation in comparison with the undoped ZnO nanoparticles. The extending light absorption towards the visible-light region and increased crystallinity of the N-doped ZnO nanoparticles contribute equally to the improved photocatalytic performance. The present vacuum atmosphere method opens up a new strategy for preparing other N-doped oxide semiconductors such as TiO₂.     

Production of micron-sized hollow microspheres by suspension polymerization of St-DEGDA (diethylene glycol diacrylate) with petroleum ether (90-120 °C)

Suspension polymerization for the droplets of the mixture with monomers, solvent, initiator in water phase with a dispersant PVA was carried out. During the polymerization the molecular weight increasing resulted in the phase separation in the droplets, and a hollow structure was formed. The influence of the hollow structure of the content of the crosslinking agent (DEGDA) and the solvent was discussed. The hollow microspheres prepared in the present study were characterized by optical microscopy (OM), scanning electron microscopy (SEM), particle size analyzer and differential scanning calorimeter (DSC).     

Fe2O3中空微球的制备与表征

以自制碳球为模板,FeCl3为原料,经水解、高温煅烧,制备出粒径约为250 nm的Fe2O3中空微球。用X-射线衍射（XRD）、透射电镜（TEM）等现代测试手段对Fe2O3中空微球样品的结构、形貌进行了表征;并考察了煅烧时间的变化对所制备的Fe2O3中空微球的晶型及形貌的影响。     

以ZnO微球为模板制备硫酸葡聚糖/鱼精蛋白胶囊及其缓释行为

以ZnO微球为模板,利用层层自组装的方法制备了壁材为鱼精蛋白(PRM)和硫酸葡聚糖(DXS)的生物可降解聚电解质胶囊. ZnO微球呈良好的单分散性,具有5 nm以上的中孔,装载荧光素后生成荧光微球. 在ZnO微球外交替吸附鱼精蛋白和硫酸葡聚糖,制得核-壳型ZnO/(DXS/PRM)8复合微球;采用稀HAC溶液去除ZnO模板后,可生成(DXS/PRM)8胶囊. 以水溶性多柔米星药物分子作为目标物,研究了该胶囊的载药和释放行为. 结果显示,该(DXS/PRM)8胶囊对多柔米星药物分子具有明显的缓释性.     

Preparation of Polycarbonate Hollow Microspheres by Microencapsulation Method

For the purpose of recycling waste polycarbonate (PC) products, PC hollow microspheres were prepared using waste PC products via a microencapsulation method. In the microencapsulation process, dichloromethane was the suitable organic solvent of the oil phase, and the optimal adding amount of gelatin was 1.7 g in 70 g water. The size of the PC hollow microspheres was analyzed by scanning electron microscopy (SEM). The hollow microspheres with mean diameter from 19 to 645 µm could be obtained by varying the preparation factors. The tap density could be controlled through the manipulation of the weight ratio of W₁ and O phase and PC concentration.     

ZnO nanostructures decorated hollow glass microspheres as near infrared reflective pigment

Hollow glass microsphere/ZnO composite pigments were successfully prepared by a facile sol-gel method. ZnO coating layers composed of nanosheets, nanoplates, or nanoparticles were anchored at the surface of hollow glass microspheres by formation of Zn-O-Si bond. A reasonable growth mechanism for elucidating the formation of ZnO nanocoating was proposed. The results indicated that the near-infrared reflectance property of the composite pigments was strongly affected by the morphology of ZnO nanostructures. The nanoparticles structures exhibited higher near-infrared reflectance than that of nanosheets and nanoplates structures. The near-infrared solar reflectance of hollow glass microsphere/ZnO composite pigments was 95.7%, while the total solar reflectance of the composite pigment was as high as 97.2%. An approximately 11.1 °C decrease in outer surface temperature was obtained for the heat box coated with composite pigments. Therefore, hollow glass microsphere/ZnO composites are excellent near infrared reflective pigments for efficient solar reflective coatings designed for building facades and roofs.     

Preparation of hollow poly(imino ether ketone) microspheres by microliquid technique

1, 4‐bis (4‐amiophenoxy) benzene and 1, 4‐Bis (4‐bromobenzoyl) benzene as monomers, poly(imino ether ketone) (PIEK) was synthesized via palladium‐catalyzed aryl amination reaction. Based on the good chemical and physical properties, big diameter (0.6–2 mm) hollow microspheres of PIEK, used for Inertial Confinement Fusion research, were prepared by using the microliquid technique and double‐layer latex technique. A new double T‐channel droplet generator was designed and developed for fabrication of controlled‐size PIEK hollow microspheres continuously. Study on manipulative condition of diameter and thickness of microspheres was done, and density matching impacting on the quality of shells was discussed. The structures of the PIEK hollow microspheres were characterized, and they possessed equal wall thickness and good spherical symmetry. The properties of the microspheres were detected, and the results showed that they showed good stability under cold environment and high temperature. Additionally, the PIEK hollow microspheres exhibited good mechanical and anti‐irradiation properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012