溶凝膠法製備InTaO4之鍍膜特性與光催化活性

Characteristics and photocatalysis of sol-gel prepared InTaO4 thin films

周宏其(Hung-Chi Chou)

指導教授 ： 吳紀聖

國立臺灣大學/工學院/化學工程學研究所/碩士(2007年)

https://doi.org/10.6342/NTU.2007.02282

摘要

InTaO4是一種光觸媒用於水分解，過去InTaO4都是利用固態高溫熔融法，必須在1100℃以上高溫鍛燒，無法用於覆膜而且不易均勻。故本研究主要是以In(NO3)3和Ta(OC4H9)5當作初始材料，使用熱水解法和酯化式溶凝膠法製備InTaO4光觸媒材料，藉由在溶液中的攪拌均勻，解決固態高溫熔融法的不均勻和降低鍛燒溫度；且藉由浸漬覆膜於石英玻片和光纖，SEM之觀測，光纖表面的觸媒層具有許多奈米級孔隙，觸媒顆粒略呈圓形，粒徑約為20 nm，觸媒層厚約40~45 nm。鍛燒後的粉末進行水溶液中二氧化碳催化還原反應，測試光催化活性，以GC-FID測得主要產物為甲醇，鎳金屬的添加皆有效地提高甲醇的產率。酯化式溶凝膠法鍛燒後的粉末，經XRD繞射圖譜分析觸媒在1100℃為InTaO4晶相，在850℃~950℃結晶性不完全，由紫外-可見光吸收波長約在500nm處。實驗發現，負載1.0wt%-NiO/InTaO4觸媒，能提升的觸媒活性，甲醇產量分別如下：鍛燒溫度850℃為16.1μmole/g-cat、900℃為23.7μmole/g-cat、950℃為27.2μmole/g-cat、1100℃為28.0μmole/g-cat，以及固態融熔法製備1.0wt%-NiO/InTaO4為20.5μmole/g-cat。

關鍵字

氧化銦鉭 ； 溶凝膠法 ； 光催化 ； 二氧化碳

並列摘要

InTaO4 is a photocatalyst used for water splitting. In the past, InTaO4 was prepared using the solid-state fusion method. By this method, catalysts are calcinated above 1100℃ and the component of InTaO4 is not uniformed. In this study, InTaO4 photocatalysts are prepared from In(NO3)3 and Ta(OC4H9)5 precursors using the thermal hydrolysis and sol-gel methods. This method solves the problems of high calcination temperature and non-uniform distribution, via mixing in the liquid phase. The prepared sol can be coated on quartz plates as well as optical fibers. From SEM analysis, the catalyst surface consists of spherical particles with nano-pores. Particle sizes are about 20nm and film thickness is ranges in 40~45nm. The calcinated catalyst powder was used in the liquid-phase photoreduction of CO2 to examine its photocatalytic activity. GC-analysis shows that methanol is the major products. XRD analysis indicates that at 1100℃, InTaO4 crystalline is formed, however at 850℃~950℃ the crystallization is incompleted. From UV-Vis spectroscoy, the photocatalyst starts to absorb light at 500nm. Experiments show that the 1.0wt%-NiO/InTaO4 has a higher photoactivity. The amount of methanol productions by catalysts calcined at various temperatures are as follows: 16.1μmole/g-cat at 850℃, 23.7μmole/g-cat at 900℃, 27.2μmole/g-cat at 950℃ and 28.0μmole/g-cat at 1100℃ respectively. The catalyst prepared by the solid state reaction method produces 20.5μmole/g-cat of methanol.

並列關鍵字

InTaO4 ； sol-gel method ； photocatalysis ； CO2

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