Hydrothermal/microwave and hydrothermal/ultrasonic synthesis of nanocrystalline titania, zirconia, and hafnia
Hydrothermal/microwave and hydrothermal/ultrasonic synthesis of nanocrystalline titania, zirconia, and hafnia
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纳米晶二氧化钛、氧化锆和氧化铪的水热/微波和水热/超声合成
DOI：
10.1134/s0036023607110022
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发表时间：
2007
影响因子：
2.1
通讯作者：
B. R. Churagulov
中科院分区：
文献类型：
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作者：
P. E. Meskin;A. I. Gavrilov;V. Maksimov;V. Ivanov;B. R. Churagulov
我们比较了二氧化钛、氧化锆和二氧化钛纳米粉末的X射线衍射（XRD）、粉末X射线衍射、TGA、TEM和BET（d = 10-15 nm）由无定形氢氧化氧钛TiO 2·nH 2 O、氢氧化氧锆ZrO（OH）2 ·nH 2 O和氢氧化氧正丁醇HfO（OH）2 ·nH 2 O使用水热（HT）、水热/微波（HT-MW）合成，和水热/超声（HT-US）方法，在150、180和250°C下处理持续0.5-24小时。从无定形氢氧化物的二氧化钛，氧化锆，和氧化铈结晶是显着增强，和热稳定的氧化锆相（m-ZrO 2）的百分比在HT-MW和HT-US过程中增加相比，传统的HT合成。所观察到的类似效应有着完全不同的原因。在这两种情况下的共同因素可能是加热处理的悬浮液的均匀性。在超声波和微波处理过程中出现的反应混合物中的局部过热也可以在加速水热过程中发挥作用。
We compare the physical-chemical properties (X-ray diffraction (XRD), powder X-ray diffraction, TGA, TEM, and BET) of titania, zirconia, and hafnia nanopowders (d = 10–15 nm) synthesized from amorphous titanyl hydroxide TiO2 · nH2O, zirconyl hydroxide ZrO(OH)2 · nH2O, and hafnyl hydroxide HfO(OH)2 · nH2O using hydrothermal (HT), hydrothermal/microwave (HT-MW), and hydrothermal/ultrasonic (HT-US) methods at 150, 180, and 250°C with treatment lasting 0.5–24 h. Titania, zirconia, and hafnia crystallization from amorphous hydroxides is substantially enhanced, and the percentage of the thermally stable zirconia phase (m-ZrO2) in the HT-MW and HT-US processes increases compared to conventional HT synthesis. The observed similar effects have completely different causes. A common factor in both cases is likely the uniformity of heating of treated suspensions. Local overheating in the reaction mixture, which appears during both ultrasonication and microwave treatment, can also play a role in accelerating the hydrothermal processes.