以溶膠-凝膠法製備奈米氧化錳

Synthesis of Nanocrystalline Manganese Oxide by Sol-gel Method

劉家維(Chia Wei Liu)

指導教授 ： 張莉毓

國立屏東科技大學/工學院/機械工程系所/碩士(2008年)

https://doi.org/10.6346/NPUST.2008.00058

摘要

氧化錳廣泛應用於催化、電化學、軟磁材料與空氣淨化等領域，而奈米氧化錳材料有許多不同於一般尺度材料之特性，因此近年來已成為重要的研究課題。本研究利用三嵌段兩性共聚物輔助溶膠-凝膠法，以醋酸錳和氯化錳為反應前驅物，製備奈米型態之結晶氧化錳。分別以TGA、XRD、FTIR、SEM、TEM及BET分析其微結構與表面型態，並探討各種合成因素例如煆燒溫度、添加不同濃度之前驅物及氫氧化鈉對氧化錳之結構影響。
實驗結果顯示，以0.015 mol的醋酸錳為前驅物者，經煆燒溫度350℃為純相之Mn3O4，而在450和550℃，除了Mn3O4並開始出現Mn2O3與MnO2的結晶相。而不同醋酸錳添加量，經煆燒溫度350℃，均為純相之Mn3O4結晶相。以0.015 mol的氯化錳為前驅物者，經煆燒溫度350~550℃均為MnO2、Mn3O4 與Mn2O3三相共存，其中又以Mn3O4為主要的相。而不同氯化錳添加量，經煆燒溫度350℃，發現亦為MnO2、Mn3O4與Mn2O3三相共存之結晶相。以NaOH添加量為0.005 M，醋酸錳為前驅物所合成之氧化錳，經煆燒溫度350℃為Mn3O4和Mn2O3之兩相共存，然而於450和550℃，則為MnO2、Mn3O4與Mn2O3之三相共存。

關鍵字

溶膠-凝膠法 ； 氧化錳 ； 醋酸錳 ； 氯化錳

並列摘要

Manganese oxides are important materials due to their wide-range applications, such as catalysts, electrochemical materials, soft magnetic materials, and for air purification. Nanostructured manganese oxide materials have unique properties in comparison with powder materials and recently have gathered increasing attention. In this study, the manganese oxides were prepared by surfactant-mediated method and the synthesis was accomplished by using triblock copolymer as the surfactant, by manganous acetate and manganous chloride as the inorganic precursors. TGA, XRD, FTIR, SEM, TEM and BET analyses were used to characterize the microstructure and morphology of the samples. The effect of experimental parameters such as calcination temperatures, the additive of precursors and NaOH on microstructure are discussed in this study.
In this study, using 0.015 mol manganous acetate as the precursor and the sample calcined at 350℃ was composed of only Mn3O4. However, as the calcining temperatures were increased to 450 and 550℃, tricrystalline (Mn3O4, Mn2O3 and MnO2) were formed. But the crystal structure of the samples prepared with manganous acetate as precursor (any concentration of manganous acetate) and calcined at 350℃ were only Mn3O4. Using 0.015 mol manganous chloride as the precursor and the samples calcined at 350~550℃ were composed of a mixture of MnO2, Mn3O4 and Mn2O3 crystal structures (Mn3O4 was the main phase). The crystal structure of the samples prepared with manganous chloride as precursor (any concentration of manganous chloride) and calcined at 350℃ also showed the mixed phases of MnO2, Mn3O4 and Mn2O3. Using 0.005 M NaOH and the sample calcined at 350℃, demonstrates the coexistence of a mixed phase with Mn3O4 and Mn2O3. However, as the calcining temperatures were increased to 450 and 550℃, tricrystalline of MnO2, Mn3O4 and Mn2O3 were obtained.

並列關鍵字

sol-gel method ； manganese oxide ； manganous acetate ； manganous chloride

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