復合光催化材料的功能設計、模塊化組裝及構效關系研究

何杰

摘 要：光催化技術是目前研究的熱點課題之一，但作為光催化技術研究的核心內容-光催化材料的設計理論與功能組裝等方面相對薄弱。該研究擬以材料復合功能設計為目標，模塊化組裝為手段，研究聚氧鈦鈮酸鹽納米片-過渡金屬離子以及金屬氧化物復合光催化劑的設計、組裝與構效關系。采用高溫固相、聚合-絡合等方法合成了規整的層狀聚氧鈦鈮酸鹽異構體如KTiNbO5和K3Ti5NbO14等作為光催化材料的基本組元，選用合適的前驅物如硝酸鹽或羰基制備對有機硫化物具有吸附作用的吸附模塊如Ni2+、Fe3+等離子和NiO和Fe2O3等氧化物，研究模塊構建與協同組裝技術，構建復合功能光催化材料；以硫醇/硫醚為探針反應物，研究復合光催化材料中有機物富集與光催化氧化功能的耦合。通過XRD、TEM、LRS、UV-vis DRS和FT-IR等表征技術對復合光催化材料的結構、光化學特征以及催化作用進行表征；并探討了反應機理。結果表明，隨著納米片單元中Ti/Nb的變化，光譜響應特征出現明顯的規律，層間過渡金屬離子與價帶電子軌道發生明顯的相互作用改變了帶隙能量。氧化物柱撐中前驅物直接影響材料的結構與組元之間的相互作用，并進而影響材料的性能。

關鍵詞：復合光催化材料 功能設計 組裝 結構化學特征 構效關系

Abstract： Photocatalytic technology is one of the hot topics in current research. However， the theoretical design and functional assembly of the photocatlytic materials are relatively weaker. The purpose of this study is to design composite functional materials using modular assembly technology， as the functional design theory， modular assembly technology and structure-activity relationship of the layered polyoxo-titanoniobate and cation or oxide nano-crystals of transition metal were researched systematically. The layered polyoxo-titanoniobates such as KTiNbO5， and K3Ti5NbO14 etc， as basic modular， which were prepared by polymerization complex method or solid state reaction method. The adsorption modular that adsorbed the organic sulfides， such as Ni2+ and Fe3+ ions， and NiO and Fe2O3， which were prepared by decomposition of its nitrate or carbonyl complexes. The composite functional photocatalytic materials were built by the modular building and collaborative assembly technology. The adsorption and photocatalytic activity was evaluated using ethyl mercaptan/dimethyl sulfide as the probe molecule. X-ray diffraction （XRD）， Transmission electron microscopy （TEM）， UV-vis diffuse reflectance spectroscopy （UV-vis DRS）， and Fourier transform infrared spectroscopy （FT-IR） etc were used to characterize the structure feature and photochemical properties of these composites， and the reaction mechanism also was suggested. The results show that the characteristics of spectral response appear regularity changes with the changes of Ti/Nb of the nanosheet unit. The significant interaction between the transition metal ions of interlayer and the valence band orbital changes the band gap energies， and the preparation method of oxide pillared precursors directly affected the interaction between material structure and the modular units， and further influence the photocatalytic properties of materials.

Key Words： Composite photocatalyst； Functional design； Assembly； Structure； Structure-activity relationship

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