Ultrafine bismuth oxide powders of high purity were prepared by electrochemical method from an aqueous solution of NaOH in the presence of dispersant.The formation mechanism of Bi2O3 powders was suggested.The effects ...Ultrafine bismuth oxide powders of high purity were prepared by electrochemical method from an aqueous solution of NaOH in the presence of dispersant.The formation mechanism of Bi2O3 powders was suggested.The effects of electrolyte,dispersant and calcining temperature were studied.Its compostion,size and microstructure were determined by IR,XRD and TEM.The results show that the sample is spherodic and dispersed evenly.Its average size is 30～40nm.The electrochemical dissolution of metal anode may be recommended as a promising technique for the synthesis of ultrafine bismuth oxide powders.展开更多
Bismuth-doped tin dioxide nanometer powders were prepared by co-precipitation method using SnCl4 and Bi（NO3）3 as raw materials. The effects of calcining temperature and doping ratio on the particle size, composition...Bismuth-doped tin dioxide nanometer powders were prepared by co-precipitation method using SnCl4 and Bi（NO3）3 as raw materials. The effects of calcining temperature and doping ratio on the particle size, composition, spectrum selectivity of bismuth-doped tin dioxide and the phase transition of Bi-Sn precursor at different temperatures were studied by means of X-ray diffraction, transmission electron microscopy, ultraviolet-visual-near infrared diffuse reflection spectrum and the thermogravimetric-differential scanning calorimetry. The results show that prepared bismuth-doped tin dioxide powders have excellent characteristics with a single-phase tetragonal structure, good dispersibility, good absorbency for ultraviolet ray and average particle size less than 10 nm. The optimum conditions for preparing bismuth-doped tin dioxide nanometer powders are as follows: calcining temperature of 600℃, ratio of bismuth-doped in a range of 0.10-0.30, and Bi-Sn precursor being dispersed by ultrasonic wave and refluxed azeotropic and distillated with mixture of n-butanol and benzene. The mechanism of phase transition of Bi-Sn precursor is that Bi 3+ enters Sn-vacancy and then forms Sn—O—Bi bond.展开更多
文摘Ultrafine bismuth oxide powders of high purity were prepared by electrochemical method from an aqueous solution of NaOH in the presence of dispersant.The formation mechanism of Bi2O3 powders was suggested.The effects of electrolyte,dispersant and calcining temperature were studied.Its compostion,size and microstructure were determined by IR,XRD and TEM.The results show that the sample is spherodic and dispersed evenly.Its average size is 30～40nm.The electrochemical dissolution of metal anode may be recommended as a promising technique for the synthesis of ultrafine bismuth oxide powders.
基金Project(GC200603) supported by the Open Fund of Guangdong Provincial Key Laboratory for Green Chemicals projectsupported by the Key Laboratory of Enhanced Heat Transfer and Energy Conservation of Ministry of Education of China
文摘Bismuth-doped tin dioxide nanometer powders were prepared by co-precipitation method using SnCl4 and Bi（NO3）3 as raw materials. The effects of calcining temperature and doping ratio on the particle size, composition, spectrum selectivity of bismuth-doped tin dioxide and the phase transition of Bi-Sn precursor at different temperatures were studied by means of X-ray diffraction, transmission electron microscopy, ultraviolet-visual-near infrared diffuse reflection spectrum and the thermogravimetric-differential scanning calorimetry. The results show that prepared bismuth-doped tin dioxide powders have excellent characteristics with a single-phase tetragonal structure, good dispersibility, good absorbency for ultraviolet ray and average particle size less than 10 nm. The optimum conditions for preparing bismuth-doped tin dioxide nanometer powders are as follows: calcining temperature of 600℃, ratio of bismuth-doped in a range of 0.10-0.30, and Bi-Sn precursor being dispersed by ultrasonic wave and refluxed azeotropic and distillated with mixture of n-butanol and benzene. The mechanism of phase transition of Bi-Sn precursor is that Bi 3+ enters Sn-vacancy and then forms Sn—O—Bi bond.
