噴霧熱分解法合成與電性能
(1. 山東理工大學(xué) 化學(xué)工程學(xué)院, 淄博 255049;
2. 上海交通大學(xué) 化學(xué)化工學(xué)院, 上海 200240)
摘 要: 用噴霧熱分解法制備La0.6Sr0.4Co0.2Fe0.8O3-α(LSCF)超細(xì)粉體材料, 用掃描電鏡和透射電鏡研究粉體的形貌與粒度, 用X射線衍射儀研究粉體材料的晶相結(jié)構(gòu), 通過(guò)能譜儀研究其元素組成和摻雜性能, 用激光粒度分析儀分析粒度分布, 并測(cè)試其電性能。 結(jié)果表明： 噴霧熱分解法合成的LSCF粉體材料粒子呈球形, 平均粒度3.13 μm, 超聲噴霧在900 ℃熱分解的產(chǎn)物能直接形成鈣鈦礦型晶相, 且經(jīng)過(guò)1 100 ℃處理后結(jié)晶度更完整； 能譜儀分析顯示噴霧熱分解法直接制成的LSCF粉體摻雜均勻；粉體的粒度符合液滴粒子轉(zhuǎn)變機(jī)理, 即1個(gè)產(chǎn)物粒子由1個(gè)液滴形成；當(dāng)加入乙醇時(shí), 粉體的粒度將減小, 但加入尿素、硝酸銨和檸檬酸時(shí)其粒度增加。 粉體的電導(dǎo)率峰值出現(xiàn)的位置為650 ℃。
關(guān)鍵字: 鈣鈦礦型復(fù)合氧化物；混合導(dǎo)體；噴霧熱分解
and its electrical property
MENG Bo1, YANG Nai-tao2
（1. School of Chemical Engineering,
Shandong University of Technology, Zibo 255049, China;
2. School of Chemistry and Chemical Technology,
Shanghai Jiao Tong University, Shanghai 200240, China）
Abstract: La0.6Sr0.4Co0.2Fe0.8O3-α (LSCF) ultrafine powders were synthesized through an ultrasonic spray pyrolysis process. The products were characterized by scanning electron microscopy and transmitted electron microscopy to observe the morphology, by X-ray diffractrometry to display the crystalline phase and by energy dispersive spectrometry to determine the elemental compositions and doping performance, and by laser particle size analyzer to analyze the particle size. Lastly, the conductivity of LSCF was tested. The results indicate that the prepared powders consist mainly of spherical particles with diameters of 3.13 μm. At the operating temperature of 900 ℃, a single perovskite crystalline phase may be formed, although the higher temperature favors the formation of perovskite structure. The energy dispersive spectrometer spectra show that the spray pyrolysis allows for the perfectly even-doping. The particle size can be adjusted by the parameters such as the concentration of precursor solution and additives. The particle size increases with increasing concentration of precursor solution and conforms to One-Droplet-One-Particle mechanism (ODOP). The particle size is decreased by addition of ethanol but increased when carbamide, ammonium nitrate or citric acid is used as the additive. Experimental result indicates that maximum conductivity occurs at 650 ℃, which is the expectation temperature for SOFC.
Key words: perovskite composite oxide; mixed conductor; spray pyrolysis
