從電腦到智慧型手機,對矽的需求量越來越大,再加上替代能源導致太陽能產業快速地發展,然而地球上的資源有限,回收再利用與尋找替代品將成為未來研究的方向。根據先前的研究指出透過酸洗可以將稻殼原有的雜質降低至0.2%.。再利用水熱長晶法提煉出純度更高的二氧化矽,以替代太陽能產業所需矽之來源。本研究利用含有豐富二氧化矽之農業廢棄物"稻殼"作為原料。首先使用3wt%的氫氯酸進行酸洗並加熱攪拌,烘乾之後再將酸洗後的稻殼使用開放式的加熱爐以800℃的高溫燃燒使其灰化。燃燒後的稻殼灰加入氫氧化納放置在高壓釜內進行不同條件的水熱反應。產物的檢測將使用熱重分析儀(Thermogravimetric analyzer)、X光繞射儀(X-Ray Diffractometer)、掃描式電子顯微鏡(Scanning Electron Microscopy)和感應耦合電漿光學放射光譜儀(Industively Coupled Plasma-Optical Emission Spectrometer)。實驗後獲得結晶性良好、粒徑均勻的六方晶二氧化矽晶粒。
Environmental issues result in that solar industries have expanded fast, but the nature resources on earth is limited. Recycling and looking for alternatives will become the directions of future researches. According to previous researches indicate that impurities in rice husk can be reduced to 0.2% by acid treatments. Then we used hydrothermal crystal growth method to extract high purity silicon dioxide (silica) which can replace the silicon source that solar industries need. In this study, we used the agricultural wastes, rice, as the raw material. Fr the first purification we used acid leaching treatment, and then reacted with sodium hydroxide by hydrothermal method. We can finally obtain fine silica particles with hexagonal structure from rice husk ash.