共查询到20条相似文献,搜索用时 0 毫秒
1.
Electrospray pyrolysis, i.e. combination of electrospray and in-flight thermal treatment, has attracted much attention as a preparation method of functional ceramic particles. In this paper, we report the processing detail of spherical TiO2 nano- and microparticles by the electrospray pyrolysis method as well as their photocatalytic activity for hydrogen evolution. Titanium(IV) bis(ammonium lactato)dihydroxide aqueous solutions (TALH aq., 0.2–20 wt%) were injected into a capillary nozzle by a syringe pump (0.15–0.59 mL/min), and were electrosprayed by using DC 4 kV voltage, followed by the pyrolysis at 300–500 °C. Spherical TiO2 nano- and microparticles were successfully obtained. Effects of precursor-liquid concentration, liquid flow-rate, and pyrolysis temperature on the particle size, microstructure and functions were discussed. 相似文献
2.
均匀沉淀法工业生产纳米二氧化钛 总被引:5,自引:1,他引:5
介绍了以硫酸法钛白生产过程中的中间产物硫酸氧钛为原料,采用直接沉淀法和均匀沉淀法制备纳米TiO2的工艺路线,通过对2种制备工艺及几种中试方案的比较,提出了纳米TiO2工业化生产的原料与技术路线,并指出在的问题及解决方法。 相似文献
3.
4.
The Fe2O3/Al composite powders were prepared by homogeneous precipitation method. The influence of the concentration of Fe2+ and the molar ratio of raw materials on the preparation of Fe2O3/Al composite powders were investigated. X-ray diffractometer, scanning electron microscope, Fourier transform infrared spectroscopy and differential thermal analysis were used to analyze the morphology and structure of the Fe2O3/Al composite powders. The results show that the content of iron oxide in the composite powders could be effectively controlled by adjusting the concentration of Fe2+ and the molar ratio of raw materials in the plating solution. The surface of Al particle was coated with a layer of thick and dense iron oxide. The core-shell Fe2O3/Al composite powders with Fe2O3 content of 14.1% were produced, the coating efficiency of Fe2O3 reaches more than 77%. The iron oxide, which coated on the surface of the aluminium particle is flower-like cluster structure, each flower-like cluster is constituted by nano-flaky iron oxide. 相似文献
5.
6.
Wang Jinkang Pang Zengyuan Jin Fangyu Ge Mingqiao 《Journal of Materials Science: Materials in Electronics》2021,32(15):20583-20597
Journal of Materials Science: Materials in Electronics - In this work, K2Ti4O9 whiskers are prepared by adding a certain amount of NaCl as the whisker reaction slow-release agent. Rutile TiO2... 相似文献
7.
通过分部固相法制备ZrW2O8粉体。以ZrW2O8、CuSO4·5H2O(分析纯)和无水Na2CO3(分析纯)为原料,采用非均匀沉淀法制备了Cu包覆ZrW2O8复合粉体,并利用XRD、SEM、EDS测试手段,分析包覆粉的物相和形貌,研究了反应液浓度、表面活性剂、反应液滴加速度等反应条件对包覆效果的影响。研究表明:通过非均匀沉淀法可以制备Cu包覆ZrW2O8复合粉体,其关键是控制反应液的浓度和滴加速度,同时,不同分子量的表面活性剂对包覆前驱体的分散性影响很大. 相似文献
8.
9.
10.
11.
以Co(N03)2.6H2O,Ca(NO3)2.4H2O为原料,柠檬酸为络合剂,利用溶胶-凝胶法(Sol-gel)制备出Ca2CO2O5粉体。采用TG-DSC、XRD和ESEM等测试方法对干凝胶体的热分解过程、样品的物相以及形貌进行了表征。实验结果表明:干凝胶体在700-900℃煅烧,煅烧2h后均能得到单相的Ca2CO2O5粉体,颗粒尺寸分布均匀,范围在1-2μm。在同一配比浓度、同一煅烧时间下,适当提高煅烧温度有利于Ca2CO2O5晶体的生长。 相似文献
12.
《Materials science & engineering. C, Materials for biological applications》2003,23(6-8):1033-1038
In present work, nanocrystalline zirconia and titania were synthesized by hydrothermal treatment of zirconyl ZrO(NO3)2 and titanyl TiO(NO3)2 nitrates aqueous solutions and amorphous gels of the corresponding hydroxides. The hydrothermal synthesis was performed in a wide range of temperatures (150–250 °C), concentration of starting solutions (0.25–0.5 M) and duration of the process (from 10 min to up to 24 h). The hydrothermal treatment at high pressure about 2.0–4.0 GPa was also carried out. The products were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and BET. Particle sizes, morphology and properties of the products were investigated. The influence of hydrothermal synthesis conditions on ZrO2 and TiO2 phase compositions were established. 相似文献
13.
A. Sadeghzadeh Attar M. Sasani Ghamsari F. Hajiesmaeilbaigi Sh. Mirdamadi K. Katagiri K. Koumoto 《Journal of Materials Science》2008,43(17):5924-5929
Well-aligned anatase and rutile TiO2 nanorods and nanotubes with a diameter of about 80–130 nm have successfully been fabricated via sol-gel template method.
The prepared samples were characterized by using thermogravimetric (TG) and differential thermal analysis (DTA), X-ray diffraction
(XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy
(EDS). The XRD results indicated that the TiO2 nanorods were crystallized in the anatase and rutile phases, after annealing at 400–800 °C for different periods of time
from 0.2 to 10 h. 相似文献
14.
Jong-Heun Lee Soon-Ja Park 《Journal of Materials Science: Materials in Electronics》1993,4(4):254-258
Spherical TiO2/SnO2 powders were prepared from the TiCl4-SnCl4 aqueous solution by ultrasonic spray pyrolysis. The particle size, particle-size distribution and morphology of the powders were studied in relation to concentration of source solutions and reaction temperatures. The width of the compositional undulation induced by spinodal decomposition in the sintered bodies increased with increasing starting particle sizes, which resulted from micro-compositional heterogeneity in the form of a solid solution within a TiO2/SnO2 secondary sphere. 相似文献
15.
《Materials Chemistry and Physics》2007,101(2-3):433-440
The controlled precipitation method allowed to the synthesis of SnO2 with advantageous specific properties, such as size and shape employing an aqueous SnCl2·2H2O solution as precursor. Through XRD analyses, the optimum pH value of the solution that yielded the desired product was found to be 6.25. After a thermal treatment at 600 °C, the final powder presented an average particle size below 50 nm with a surface area of 19 m2 g−1 and a large reactivity. The evolution of the most important functional groups during the steps involved in this synthesis route is explained in view of the results obtained with FTIR and XRD. A thorough discussion on the different intermediates involved in the whole process is presented on the basis of hydrolysis and condensation reactions. The conclusions are supported with a complete characterization through differential and gravimetric thermal analysis (DTA/TGA), electron microscopies (SEM/TEM) and surface area determinations (BET). 相似文献
16.
TiO2-SnO2纳米粉末的制备及表征 总被引:6,自引:0,他引:6
以廉价的无机盐为原料,采用溶胶-凝胶(Sol-Ge l)法制备了TiO2-SnO2纳米粉,并采用DTA、XRD、TEM技术对粉体进行了表征.实验结果表明:用该法制得的TiO2-SnO2超细粉体粒径在5~7 nm左右. 相似文献
17.
Weiwei Li Yin Zhao Shuai Yuan Liyi Shi Zhuyi Wang Jianhui Fang Meihong Zhang 《Journal of Materials Science》2012,47(23):7999-8006
Anatase TiO2 nanocrystal colloids with high dispersion and photocatalytic activity were rapidly synthesized from peroxo-titanium-acid precursor by microwave-assisted hydrothermal method within 30?min at low temperature (120–180?°C). The transmission electron microscopy results indicate that the as-prepared TiO2 have a narrow particle size distribution (25–29?nm) and high dispersion. The crystal structure of all these products are pure anatase phase (XRD, Raman), and they show good crystallinity and large surface area (N2 adsorption–desorption measurements BET). The results of the UV–Visible absorbance and Fourier transform infrared spectra indicate that the surface peroxo group Ti(O2) still remains in TiO2 nanoparticles prepared by microwave-assisted hydrothermal method at 120?°C, and this surface peroxo group can be decomposed effectively by drying at 140?°C. The photocatalytic activity of the as-prepared TiO2 were evaluated by the degradation of reactive brilliant red X-3B, it is found that the as-prepared TiO2 exhibited good photocatalytic performance. Moreover, the existence of surface peroxo group greatly suppressed the photocatalytic activity of the TiO2 nanoparticles. 相似文献
18.
《Materials Letters》2006,60(17-18):2101-2104
Nano TiO2 coated commercial nano ZrO2 powders (20 and 80 wt.%) were synthesized by a sol–gel process. Their microstructure and crystal structure depending on the calcination temperatures were investigated using XRD and HRTEM techniques. In the as-received powders, the nano TiO2 particles attached to the ZrO2 particles existed in an amorphous phase. After calcination at 450 and 600 °C, most of the TiO2 powders were crystallized to an anatase type, whereas at 750 °C, they were changed to a rutile phase.From the comparison of photocatalytic activity, the nano TiO2 coated ZrO2 powders calcined at 450 and 600 °C showed excellent efficiency for the removal of methyl orange (MO). However, in the powders calcined at 750 °C, the photocatalytic activity was decreased due to the appearance of a rutile phase. 相似文献
19.
20.
SnO2/TiO2 nanotubes composite photocatalysts with different SnO2 contents were successfully synthesized by means of a simple solvothermal process. The synthesized products were characterized physically by X-ray diffraction (XRD) and high-resolution transmission electron microscope (HRTEM). The composite photocatalysts can not only make the target pollutant, methylene blue (MB), adsorbed at a high concentration level around the surface of the composites but also decrease the recombination rate of electron-hole pairs so as to achieve good photocatalytic performance. The effect of SnO2 contents on the photocatalytic activities of the composites was also investigated. The results showed that the SnO2/TiO2 nanotubes composite photocatalyst with 5 wt.% SnO2 loading had the highest photocatalytic efficiency. 相似文献