摘 要
本研究分為三階段，第一階段 利用有機前導物法製備奈米級鈦酸鍶粉末，嘗試不同熱處理(300℃、400℃)條件下製備前導物，探討不同時間下於450℃持溫煆燒對合成SrTiO3粉末之影響，以求達到合成粉末低溫(<500℃)和奈米級(<100nm)之效果。第二階段 進行UV-Visible分析和亞甲基藍光解實驗，以有機前導物法製備的粉末配合TiO2(P-25)和商用SrTiO3粉末做為比較，以此了解鈦酸鍶光催化性質及能力。第三階段 利用在第一階段中掌握的實驗參數，製備出含Cr3+之鈦酸鍶粉末，期能使SrTiO3粉末達到吸收可見光的效果。研究結果如下:

1.發現300℃前導物(Precursor)於450℃-12h合成出SrTiO3粉末，並將粉末控制在20nm上下，且粉末的凝聚情形並不嚴重，成功改善有機前導物法的缺點。

2.配合TiO2(P-25)和商用SrTiO3粉末進行UV-Visible分析和亞甲基藍光解實驗做為比較，實驗的結果顯示P-25光催效能為最佳，商用SrTiO3粉末次之，之後是有機前導物法製備的SrTiO3粉末，而固態反應法所製備的SrTiO3粉末光催化效果最差。

3.製備SrTi(1-X)CrXO3 (X= 0.02、0.04和0.08)添加Cr離子之凝膠(Gel)，可於在450℃-24h生成單一結晶相，當Cr的添加量為2和4%(X=0.02和0.04)時，在可見光區域產生大量的吸收效應；但當Cr含量為8%時(X=0.08)，造成在反應過程中產生未知相，以致於無法達成吸收可見光之目的。

Abstract
There are three stage in this study：
(1) SrTiO3 powders were prepared by the organic precursor method. 300℃ and 400℃ heat-temperature were used to produced precursor and the precursors were decomposed at 450℃for various times to obtain nano-sized(<100nm) SrTiO3 powders;
(2) UV-Visible spectrum analysis and Methylene Blue decolourization test were used to evaluate the photocatalytic properties of different SrTiO3 and TiO2(P-25) powders;
(3) Naon-sized SrTiXCr(1-X)O3 (X= 0、2、4、8%) powders were prepared by the organic precursor method in order to produce photocatalyst capable of using visible light. Experimental results are given as follows:

1. Calcinating the 300℃precursor at 450℃ for 12h produced SrTiO3 powders with an average size of 20nm. The produced SrTiO3 powders are not seriously agglomerated.

2. Results of UV-Visible spectrum analysis and Methylene Blue decolourization test shown that photocatalytic efficiency followed the following order: P-25＞industry SrTiO3 powders＞SrTiO3 powders produced by the organic precursor method＞SrTiO3 powders obtained by the solid state reaction method.

3. SrTiXCr(1-X)O3 (X= 0、2、4、8%) powder were prepared by calcinating the organic precursor at 450℃ for 24h. For X=2% and 4% samples，the UV-Visible spectrum absorption edge moves to the visible region, but X=8% sample does not produce red-shift presumably due to the unknown phase generated during calcination.

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