无定形Al2O3基异质结纳米粉体负载离子液体吸附耦合光催化氧化脱硫研究

Photocatalytic oxidation desulfurization of fuel oils has attracted increasing attention and research due to its high efficiency, clean, and low cost. However,the use of UV light as light source restricts its utilization in industry. Based on the facts that amorphous Al2O3 has photocatalytic activity and the trasfer ability for photo-induced carriers, combining with the performance that narrow gap semiconductors can absorbe visible light, amorphous Al2O3-based hybrid photocatalysts with high specific surface area and high visible light photocatalytic activity would be synthesized via reverse supports-solution combustion. Then ionic liquids will be supported on these photocatalysts and high effeciency degradation of sulfur-containing compounds will be achieved via photocatalytic oxidation coupled with adsorption. The seperation and transfer mechanism of photo-induced carriers will be proposed through invesitigating photocatalytic abilities of varous hybrid materials and active oxidant species in the reaction process. Photocatalytic reaction mechanism over Al2O3-based hybrid photocatalysts will be proposed and the levels of valence band and conduction band of amorphous Al2O3 will be illustrated. Structure-activity relationship of composition, structure and photocatalytic performance will be established. Then the metal chlorides-based ionic liquids will be chemically bonded supported on the photocatalysts.The synergistic effects of desulfurization between adsorption caused by ionic liquids on the surface of support and the photocatalytic effect induced by photocatalyst will be studied and discussed. The degradation route and mechanism of sulfur-containing compounds under adsorption and photocatalysis will be investigated. This project will provide idea for development of high-efficience visible-light driven photocatalysts, improve the utilization of sunlight in clean energy field and provide reference for deep desulfurization of fuel oils in industry.

光催化氧化燃料油脱硫作为高效、清洁、低成本技术，一直受到关注与研究，但目前多利用紫外光源，应用受到限制。基于本课题组发现的无定形Al2O3具有光催化活性及可转移光生载流子的能力，结合窄禁带半导体可吸收可见光的性能，拟以反向载体-溶液燃烧法合成具有高效可见光活性的高比表面无定形Al2O3基异质结光催化剂，并负载离子液体，通过吸附耦合光催化实现可见光下燃料油深度脱硫。通过考察不同半导体异质结催化剂活性以及光反应中产生的活性氧物种，阐明异质结材料界面光生载流子分离及迁移机制，提出其光催化机理，建立异质结材料组成及结构和活性间的构效关系，并确定无定形Al2O3能带位置；采用化学键合负载金属基离子液体，考察其吸附含硫化合物与光催化间的协同效应，探讨协同作用下含硫化合物的降解途径与氧化机理。本研究可为新型高效可见光催化剂的开发提供思路，推进清洁能源领域对太阳光的利用，为燃料油脱硫工业化提供参考。

燃料油中含硫化合物燃烧生成的硫氧化物是造成雾霾等环境污染的主要来源之一，采用温和方法脱除燃料油中硫化物是环境净化领域的备受关注的课题。光催化氧化燃料油脱硫作为高效、清洁、低成本技术，一直受到关注与研究，但目前光催化剂成本较高，且生产过程复杂，制约了光催化技术的推广。本项目开发了新型价格低廉的光催化剂及离子液体，以为光催化氧化或氧化脱硫提供参考。具体工作如下：.1. 以燃烧合成开发了无定形Al2O3光催化剂，在此基础上合成了Al2O3/g-C3N4异质结，发现燃烧合成的Al2O3表面缺乏羟基阻碍了其与g-C3N4的结合。通过对g-C3N4的表面羟基改性揭示了影响g-C3N4基异质结作用力的主要因素是材料表面的羟基基团，为g-C3N4基异质结的设计提供了理论依据。提出了Al2O3的能带位置，为Al2O3在光催化领域的应用提供了基础，并基于能带匹配构建了Al2O3/BiOCl异质结，考察了其分子氧活化能力；.2.以水热法合成了具有更高比表面积和更多缺陷位的无定形Al2O3，利用水热合成原位构建了Al2O3/g-C3N4异质结，发现了Al2O3和g-C3N4在水热过程具有配位及相互修饰作用，该作用可以使g-C3N4晶体重新生长并保持Al2O3的高比表面积。提出了无定形物质的晶格匹配作用，为无定形物质的应用提供了新的思路。并基于晶格匹配和能带匹配的理念构筑了g-C3N4 /Al2O3/ZnO三元异质结，研究了其瀑布式电子流动机制；.3.合成了价格低廉的NMP∙xFeCl3 和[Hnmp]Cl∙xFeCl3离子液体，探讨了Lewis酸性对其萃取脱硫性能影响，提出了Lewis酸性是影响萃取脱硫效果的主要因素。研究了离子液体催化双氧水分解机制，提出了 •OH和O2•-等活性氧物种的产生途径；制备了负载型离子液体，揭示了羟基为离子液体与载体的结合起到重要作用。考察了固载化离子液体的萃取/催化氧化脱硫性能；.4. 合成了其他FeAl2O4、MgAl2O4等铝基尖晶石型光催化剂，研究了它们的能带组成，考察了燃料种类等对FeAl2O4前驱体盐分解及FeAl2O4形成的影响。利用燃烧合成一步构建了多种铋系材料异质结，探讨了表面氧空位等对材料能带位置的影响，考察了异质结间光生电子-空穴的转移及分离途径，研究了活性自由基物种及其对光降解能力的影响。