微/纳多孔结构Fe3O4构筑及调控羟基自由基增强去除有机污染物研究

Fenton technology, as an advanced oxidation processes, has attracted the most intensive attention to remove complex and refractory organic pollutants in the environment. The concentrated and disordered release of the highly active hydroxyl radicals (•OH), leads the scavenging and self-consumption of •OH. As a result, the utilization rate of •OH in Fenton system is rather low and the degradation of organic pollutants is incomplete. Thus, the nodus for Fenton system to efficiently remove the organic pollutants is the screening and fine structure tuning of catalyst, which can induce the ordered release of •OH and improve the •OH utilization rate..In this project，we intend to choose Fe3O4, a kind of peroxidase mimetic substance, as the catalyst in Fenton system. We are going to tune the high-energy crystal and the microstructure（size, shape, assembly method, etc.）by controlling the hydrothermal synthesis parameters, fulfill the orderly self-assembly of lower-dimensional nano-unites，and finally obtain micron/nanosized porous structure Fe3O4 with both nano and micro scale advantages. And we aim to the orderly releasing of •OH by tuning the microstructure of the catalyst to improve the utilization rate of •OH, and finally achieve the efficient removal of the refractory organic pollutants (using 2,4-D pesticide as target pollutant) in the environment. We will systematically study the effect of the material structure parameters on both catalytic activity to H2O2 and the orderly releasing of •OH, and further investigate the tuning mechanism of •OH by the catalyst. It is expected the project will provides materials basis and technical feasibility for the development of Fe3O4 based heterogeneous Fenton system.

Fenton高级氧化技术是去除环境中复杂和难降解有机污染物研究热点。然而，体系中高活性羟基自由基(•OH)的集中释放，引发•OH间湮灭和吞噬，导致•OH利用率不高，是有机污染物降解不完全的主因。因此，选择催化剂，控制材料微结构，调控•OH有序释放，提高•OH利用率，是Fenton体系高效去除有机污染物的难点。.本项目选择有类双氧水催化活性酶的Fe3O4作为Fenton体系催化剂，以水热法为主，控制合成参数，调控材料微结构（尺寸、形貌、组装方式等），引入高能晶面控制，经功能纳米单元的有序组装，获得兼具纳米和微米材料优点的微/纳结构多孔Fe3O4。通过结构调控催化双氧水有序释放•OH，提高•OH利用率，高效去除环境中难降解有机污染物（以2,4-D农药为目标物）。系统研究材料的结构参数对双氧水催化活性和调控•OH有序释放的影响，探索催化调控机理。为发展异相Fenton体系提供材料基础。

Fenton高级氧化技术是去除环境中复杂和难降解有机污染物研究热点。然而，体系中高活性羟基自由基(•OH)的集中释放，引发•OH间湮灭和吞噬，导致•OH利用率不高，是有机污染物降解不完全的主因。因此，选择催化剂，控制材料微结构，调控•OH有序释放，提高•OH利用率，是Fenton体系高效去除有机污染物的难点。.本项目选择有类双氧水催化活性酶的Fe3O4作为Fenton体系催化剂，以氯化铁为铁源，通过不同种类的还原剂提供二价铁，以尿素作为碱源，通过溶剂热法，控制合成参数，获得多种微结构（尺寸、形貌、组装方式等）材料，经功能纳米单元的有序组装，获得兼具纳米和微米材料优点的微/纳结构海胆状Fe3O4及针状Fe3O4/ZnFe2O4。通过结构调控催化双氧水有序释放•OH，提高•OH利用率，高效去除环境中难降解有机污染物。系统研究材料的结构参数对双氧水催化活性和调控•OH有序释放的影响，以对苯二甲酸作为示踪分子，通过荧光光谱法研究•OH释放规律，发现在相同条件下，微纳结构Fe3O4及Fe3O4/ZnFe2O4能够提高•OH释放效率，这是由于其微纳结构能够暴露更多的活性位点，吸附和催化更多的•OH，微纳结构的分级结构特点能够使得•OH有序释放，从而避免•OH集中释放产生的湮灭和吞噬，提高•OH利用率。为发展铁基氧化物异相Fenton体系提供材料基础。