本文選題：摻鋁氧化鋅 + 溶劑熱法��； 參考：《哈爾濱工業(yè)大學》2016年博士論文

【摘要】：摻鋁氧化鋅(AZO)具有優(yōu)異的電學和光學等性能,被廣泛應用在熱電、太陽能電池、氣敏和光催化等領域。本文采用溶劑熱法,通過合理設計實驗方案,得到以暴露特定晶面為主的形貌各異的AZO粉體,揭示了AZO晶體生長及形貌演變機制,為AZO材料的可控合成提供理論基礎和技術支持�；贏ZO粉體制作了氣敏元件,研究AZO形貌和結(jié)構(gòu)與氣敏特性的內(nèi)在關系,建立氣敏機制模型�；谀軒ヅ淅碚�,設計并合成金屬酞菁配合物敏化AZO光催化劑,研究其能帶結(jié)構(gòu)對光催化性能的影響,揭示了光催化降解機制。主要研究內(nèi)容如下:以乙酸鋅為鋅源,硝酸鋁為鋁源,六亞甲基四胺為堿源,采用溶劑熱法,通過改變反應物濃度、水和乙醇混合溶劑的配比、添加劑種類、摻鋁量、反應時間和反應溫度,合成出不同形貌的AZO粉體,利用XRD、SEM、TEM和HRTEM、XPS、IR等分析其晶體結(jié)構(gòu)、形貌和化學組成等,得到了以暴露(0001)晶面為主的7種不同形貌的AZO粉體,分別為片狀、花朵狀、啞鈴狀、仙人掌狀、花球狀、米粒狀及棒狀�；诘谝恍栽砻芏确汉碚�,利用CASTEP軟件包對ZnO的表面能進行了計算,發(fā)現(xiàn)其(0001)晶面吸附水分子后表面能降低,基于此結(jié)果,探究晶體生長過程和形貌演變規(guī)律。將AZO粉體制作成旁熱式氣體傳感器,結(jié)果發(fā)現(xiàn)最佳工作溫度為332℃,對乙醇具有高選擇性,對乙醇的響應恢復性能好;研究AZO形貌和鋁的摻雜量對氣敏性能的影響,發(fā)現(xiàn)暴露大量(0001)晶面的片狀AZO和鋁摻雜量為3 at.%時氣敏性能最佳�；诘谝恍栽砻芏确汉碚�,計算得到,片狀AZO提供最多的(0001)晶面以吸附最大量乙醇分子,從而表現(xiàn)出對乙醇氣體的高選擇性和靈敏性,這與氣敏性能的實驗結(jié)果相一致。為探究AZO氣敏機制,進行了動力學實驗并建立氣敏反應的速率方程,其吸附反應為準一級反應,確定吸附形式是O2-。研究了AZO靈敏度與晶粒尺寸的關系,建立AZO的表面耗盡層模型。提高可見光利用率和開發(fā)高效光催化材料是目前光催化領域的熱點問題。本論文設計并合成能級匹配的敏化AZO光催化劑。首先成功合成4種金屬酞菁配合物敏化劑(Cu Pc(iso-PeO)_8、CoPc(iso-PeO)_8、Ni Pc(iso-PeO)_8和Pb Pc(isoPeO)_8)和敏化AZO光催化劑。研究敏化AZO光催化降解亞甲基藍的效率,發(fā)現(xiàn)敏化使AZO的吸收波長紅移21 nm,其光催化活性提高約30%。分別研究了敏化劑種類、AZO形貌及摻鋁量對光催化降解亞甲基藍的影響,發(fā)現(xiàn)PbPc(iso-PeO)_8敏化劑、花朵狀形貌和3 at.%摻鋁量的影響最大。為探究敏化AZO的光催化機制,設計了動力學實驗,確定光催化降解亞甲基藍的反應為準一級反應,速率系數(shù)k分別為0.08653 min-1(花朵狀)、0.0590 min-1(片狀)和0.0517 min-1(啞鈴狀)。對敏化AZO的光譜分析表明它具有type II交錯式能帶結(jié)構(gòu),這有效改善了光生載流子的分離并抑制其復合,能夠?qū)崿F(xiàn)ROS引發(fā)的一系列光降解反應。
[Abstract]:Aluminum-doped zinc oxide (AZO) has been widely used in thermoelectricity, solar cells, gas sensing and photocatalysis due to its excellent electrical and optical properties. In this paper, AZO powders with different morphologies are obtained by using solvothermal method and reasonable design of experimental scheme. The mechanism of AZO crystal growth and morphology evolution is revealed. It provides theoretical basis and technical support for controllable synthesis of AZO materials. Based on the AZO powder, the gas sensing elements were fabricated. The relationship between the morphology and structure of AZO and the gas sensing characteristics was studied, and the gas sensing mechanism model was established. Based on the energy band matching theory, the metal phthalocyanine complexes sensitized AZO photocatalysts were designed and synthesized. The influence of the band structure on the photocatalytic performance was studied, and the photocatalytic degradation mechanism was revealed. The main contents are as follows: zinc acetate as zinc source, aluminum nitrate as aluminum source, hexamethylenetetramine as base source, solvothermal method, by changing the concentration of reactants, the mixture ratio of water and ethanol, the type of additives, the amount of aluminum, AZO powders with different morphologies were synthesized by reaction time and reaction temperature. The crystal structure, morphology and chemical composition of AZO powders with different morphologies were analyzed by XRDD-SEMMA-TEM and HRTEM-XPS-IR, respectively. Seven kinds of AZO powders with different morphologies were obtained, respectively, which were flaky. Flower-shaped, dumbbell-shaped, cactus-shaped, flower globular, rice-shaped and rod-shaped. Based on the first-principle density functional theory, the surface energy of ZnO was calculated by using CASTEP software package. It was found that the surface energy of ZnO adsorbed on the crystal surface was decreased. Based on the results, the law of crystal growth process and morphology evolution was investigated. The AZO powder was prepared into a side heat gas sensor. The results show that the optimum working temperature is 332 鈩，

本文編號：1957576