Synthesis and Characterization of Monodispersive Indium oxide-In2O3 and Strontium Indate-SrIn2O4

本研究的目的在於探討利用水熱法(Hydrothermal process)的方式合成氧化銦(indium oxide, In2O3)陶瓷粉體，以及利用噴霚熱分解法(Spray pyrolysis)合成球狀的銦酸鍶(SrIn2O4)陶瓷粉體的機制及性質的研究。於合成的過程中加入添加劑，如尿素(urea)、硝酸鍶(Sr(NO3)2)、及聚乙稀氮環戊烷(PVP(polyvinylpyrrolidone))等，來探討添加後對最後生成之氫氧化銦析出物之影響。合成粉體之性質研究則利用X光繞射法(XRD), 熱重分析法(TGA), 示差掃描熱卡儀(DSC), 穿透及掃描電鏡(TEM,SEM), 氮氣吸附表面積儀(BET), 感應偶合電漿原子發射光譜儀(ICP-OES)及光子激發螢光儀(PL)等分析儀器來得到。此外，銦離子在熱水環境中水解的動力學在本實驗中也將被探討。在動力學的研究中發現在添加尿素的系統中，銦之析出物之反應是屬於零次反應，反應活化能為128 kJ/mol。與文獻比較後，可得銦之水解反應是受到尿素分解反應所控制。在高溫煆燒的實驗中了解氫氧化銦之析出物可在300oC的煆燒條件下轉成氧化銦，在900oC的煆燒條件下，也能保持顆粒原來的形態。利用噴霚熱分解法生成次微米之球形銦酸鍶螢光粉體也在此研究中被討論，尤其螢光測試結果發現，氧化銦顆粒在煆燒至830oC及930oC後，放出之光譜是屬於藍光範圍，不同合成條件以及不同煆燒溫度之影響在此研究中也被詳細討論。The objectives of this study were to synthesize submicron, monodispersive In2O3 and SrIn2O4 particles through a hydrothermal or spray pyrolysis processes. In order to control the morphologies of the particles, the formulations used PVP (polyvinylpyrrolidone) and urea as the additives. By using X-ray diffractometer (XRD), thermogravimetry analyst (TGA), differential scanning calorimetry (DSC), transmission electron microscope (TEM), scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET), inductively coupled plasma- optical emission spectrometry (ICP-OES) and photoluminescence (PL), the properties of those particles were analyzed. The kinetics of the hydrolysis reaction of In3+ was studied, and showed that oval-shape or stick-like InOOH particles precipitated first, then grew to cubic In(OH)3 particles in the hydrothermal process. The precipitation kinetics was studied to be the zero order reaction with an activation energy of 128 kJ/mol and controlled by the decomposition kinetic of urea. The influence of Sr+2 additive, synthesizing temperature, concentration of urea and PVP agents was investigated. Calcination of the hydrates to form In2O3 particles by heating over than 300oC was conducted, and the original morphologies could be maintained when those precipitates were calcined at 900oC. The 830oC and 930oC calcined In2O3 particles showed characteristic photoluminescence properties in blue light range. The possible route for the synthesis of spherical SrIn2O4 particles was tried and discussed.摘 要 I Abstract II Content III List of Figures V List of Tables IX Chapter 1 Introduction 1 Chapter 2 Literature Review 3 2-1 Luminescence materials 3 2-1-1 Basic Concept of Luminescent Materials 3 2-1-2 Potential Energy Diagram 7 2-1-3 Design of Phosphors 7 2-1-4 Phosphors Characterization 9 2-1-5 Synthesis Techniques 12 2-2 Monodispersive Particles 15 2-3 Structure of SrIn2O4, In2O3 and In(OH)3 22 Chapter 3 EXPERIMENTAL PROCEDURE 24 3-1 Material 24 3-2 Synthesis of Monodispersive and Submicron In2O3 Particle 24 3-3 Characterization Technique 31 3-3-1 Observation of Particles Size and Morphology 31 3-3-2 Thermo Analysis of Particle 31 3-3-3 Phase Identified 31 3-3-4 Specific Surface Area 32 3-3-5 Residual Ion in Solution 32 3-3-5 Photoluminescence Measurement 32 Chapter 4 Results and Discussion 33 4-1 Effect of Urea Addition 33 4-1-1 Properties of the Precipitates Prepared at 85oC 33 4-1-2 Properties of the Precipitates Prepared at 65oC 45 4-1-3 Reaction Kinetics 68 4-2 Effect of Sr2+ 77 4-2-1 Stoichiometric Ratio of In/Sr 77 4-2-2 Non-Stoichiometric Ratio of In/Sr 86 4-3 Effect of PVP Addition 92 4-4 Spray Pyrolysis 97 4-5 Photoluminescent (PL) Measurement 109 Chapter 5 Conclusions 114 Reference 11