調控鋯金屬有機框架之孔徑與光學特性應用於新興污染物之光分解

Abstract

為了增加光觸媒對水中新興污染物的選擇性以及增強對廢水中抗生素的光催化效率，我們合成了金屬有機框架材料（VNU-1）。VNU-1是一種由鋯金屬以及有機配位基（H2CPEB）自組裝所形成的金屬有機框架。由於它的有機配位基的長度較長，因此所合成的VNU-1有著比其它金屬有機框架更大的孔徑。在對磺胺甲惡唑的吸附實驗中，吸附量隨著金屬有機框架的孔徑增大而變多。與 UiO-66光觸媒相比，VNU-1的吸附效率比其高7.5倍，且在照光10分鐘後即可達到100% 的降解效果，而相同時間下UiO-66只達到30% 的降解效率。VNU-1的高效能主要歸功於其高吸附能力，較寬的吸光特性以及比較不容易再結合的電子電洞對特性。 除此之外，VNU-1的孔徑大小使其擁有對小分子抗生素以及大分子腐植酸的選擇性。VNU-1可以通過吸附小分子的抗生素並進一步光降解以達到降解抗生素，並留下對水體有益的腐植酸的效果。觸媒的再利用測試中也顯示VNU-1在5個循環之後仍然保持著極高的光催化效率。毒性測試也表明，抗生素的光分解產物並沒有對費氏弧菌產生任何毒性作用。基於以上結果，VNU-1是一種適合處理水中污染物的光觸媒。最後，此研究也為開發有機金屬框架以增強污染物吸附以及光催化效果提供了另一個視角。

In order to achieve size-selective property and enhance the photocatalytic activity of the photocatalyst on emerging contaminants in the water systems. VNU-1, a kind of Metal-Organic Frameworks (MOFs) with enlarged pore size and ameliorated optical properties by elongating the organic linker was synthesized and applied in this field. In comparison with UiO-66 MOF, VNU-1 has reached 7.5 times higher adsorption and a 100% photodegradation on sulfamethoxazole in 10 minutes while UiO-66 reached only 30% photodegradation. The effective performance was benefited from the outstanding adsorption capacity, wide light-harvesting properties, and the prolonged lifetime of photoinduced charge carriers of VNU-1. Moreover, the tailored pore size of VNU-1 also resulted in the size-selective properties between small-molecule antibiotics and big-molecule humic acid. VNU-1 also maintained high photodegradation performance after 5 cycles and the toxicity test has shown that the photodegradation products have no toxic effect on V. fischeri bacteria. These results indicating that VNU-1 is a promising photocatalyst. This study also provided a new sight for developing MOFs photocatalyst to eliminate emerging contaminants in the wastewater systems.