本論文之研究目的是以溶膠凝膠法合成具擇優晶面的六鈮酸鉀光觸媒材料，並藉由X光繞射分析、掃描式電子顯微鏡、穿透式電子顯微鏡、紫外-可見光漫反射分析、拉曼光譜分析結合模擬計算來探討光觸媒結構對光分解水特性之影響。
由X光繞射分析以及穿透式電子顯微鏡觀察可以得知，本研究所合成出的六鈮酸鉀為含有結晶水的斜方體結構，所得顆粒尺寸為1-2 μm，能隙值為3.6 eV，配合模擬六鈮酸鉀模型得到(0 4 0)、(2 3 1)、(0 12 1)晶面，因(0 4 0)晶面上未佔據任何金屬離子，無法吸附氫氧基，而(2 3 1)、(0 12 1)晶面上有鉀離子與鈮離子的存在，氫氧基可在鈮離子上吸附增進產氫效率，結合產氫結果，發現(0 4 0)晶面與產氫速率並無直接關係，而(0 12 1)與(2 3 1)的繞射強度比值與產氫速率成正比，又由拉曼光譜來看，950 cm-1譜帶代表NbO6八面體高度扭曲排列區域，結晶水的嵌入造成NbO6結構排列扭曲明顯地表現在950 cm-1譜帶的強度上，因結晶水的嵌入把層間距離撐開而增加觸媒邊緣的反應位置，與模型切面結果相印證，其強度亦與產氫速率有正比的關係。

The goal of this study is to synthesize K4Nb6O17 photocatalysts with a preferred plane by the sol-gel method and to discuss the effect of the preferred plane and the structure of material on the catalytic efficiency of K4Nb6O17 towards water splitting reaction. The synthesized materials are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visible diffusion reflection and Raman measurements and correspondingly carried out simulations for better understanding of the photocatalytic properties.
It was found that the synthesized the hydrated K4Nb6O17 shows orthorhombic structure. The particle size and the band gap are 1-2 μm and 3.6 eV, respectively. These results are integrated with simulation model to get (0 4 0), (2 3 1) and (0 12 1) planes. The (0 4 0) plane appeared to be less active towards hydroxyl adsorption due to the absence of any cations on the plane. There have niobium cation and potassium cation on (2 3 1) and (0 12 1) planes. It will makes the hydroxyl adsorbed on the niobium cation ,and improve the rate of H2 evolution. From the results of H2 evolution, it appeared that the (0 4 0) is independent of activity. The XRD peak ratio of (0 12 1) to (2 3 1) is proportionate to the rate of H2 evolution. In the Raman spectrum of the photocatalyst, the band appeared at 950 cm-1 is indicative of highly distorted area of the NbO6 octahedral. The distorted orientation in NbO6 structure may cause by the intercalation of the water of crystallization and shows the intensity of 950 cm-1 band. Due to the intercalation of the crystallized water in the interior layer, the distance of interior layer may increase and increases the reaction site of the edge of the catalyst. Interestingly the result obtained from the simulation is matched well with the Raman spectra. Thus, the intensity of 950 cm-1 band is also proportionate to the rate of H2 evolution.

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