本研究是以碳球做為模板,製備氧化鎳中空球。金屬氧化物中空球有幾種製備方法,如溶膠-凝膠法、水熱法、模板法、噴霧熱解法等。最常用葡萄糖或蔗糖通過水熱法製備出的碳球做模板製備金屬氧化物中空球,而水熱法製備出的碳球表面會存在─OH和─C=O鍵。 本研究將改善水熱法的缺點,以微波法製備碳球模板。微波法具有下列特性:(1)反應速率較快 (2)溫和的反應條件 (3)較高的化學純度 (4)使用較低的能量。 實驗分為製備碳球模板及合成NiO中空微球二部分。碳球模板:使用葡萄糖,利用微波法製備碳球模板。NiO中空微球:以硫酸鎳、尿素做為原料,碳球為模板,水做為反應的溶劑,反應溫度為60℃進行合成反應。並研究微波的功率、時間對碳球模板表面形態的關係,以及改變不同反應時間、原料變化對產量的影響,以SEM、XRD、SEM/EDX觀察其表面型態、結晶構造。 根據實驗結果,製備碳球模板的微波條件為350W、時間3小時可得到較佳的模板。NiO中空微球,產量會隨著反應時間增加而增加;NiO的粒徑隨碳球粒徑增加而增大,微球壁隨碳球量增加而變薄。
In this study, the carbon spheres as templates, is used prepare the NiO hollow spheres. Metal oxide hollow sphere have been synthesized successfully by various methods, such as templating method, sol-gel method, hydrothermal method, spray pyrolysis method and so on. The most-applied method for the synthesis of metal oxide hollow spheres is by far the templating of carbon spheres prepared by dehydrating glucose or sucrose under hydrothermal conditions, the surface of the carbon sphere have a well distribution of ─OH groups and ─C=O groups. This study will improve the disadvantage of hydrothermal method. We use microwave to prepare because it has several characteristics: (1) faster reaction rate, (2) milder reaction conditions, (3) higher chemical yield, (4) lower energy consumption. The experiment was divided into two parts, the preparation of carbon sphere templates and the synthesis of NiO hollow microspheres. Carbon sphere templates : carbon spheres prepared by dehydrating glucose under microwave conditions. NiO hollow microspheres: nickel sulfate and urea as raw materials, carbon spheres as templates, water as a reaction solvent, synthesis reaction at 60 ℃. Study the relationship between microwave power, time and carbon spheres templates of surface shape, and effect between reaction time, raw materials and yield. We explore morphology, the crystalline phases by SEM, XRD and SEM/EDX. According to the experiments, we found that better template in the microwave conditions for the 350W, and the microwave time was 3 hr, the NiO hollow microspheres of yield increasing as the reaction time increases; NiO of particle size increasing as the carbon sphere diameter increases, the shell thickness thinning as the carbon sphere increases.