摘要
双酚S因其优良的物化稳定性，被视为双酚A的理想替代物，广泛应用于聚碳酸酯、环氧树脂、聚酯树脂、聚砜、聚醚砜等高分子材料的合成。同时，作为双酚A的代替品，它也被大量应用于热敏打印纸、食品包装等日常品的生产。然而，随着研究深入发现，双酚S也具有与双酚A类似的生理毒性。更令人堪忧的是，双酚S已在地表水体中被频频检出，这对人类健康构成了潜在的威胁。因此，实现水中双酚S的高效去除，对改善水生环境具有重要的现实意义。
与传统芬顿技术相比，均相光芬顿技术在一定程度能弥补传统芬顿技术的不足，然而它依然存在反应条件苛刻（pH≤3）、污泥产量多等问题。针对这些问题，本研究通过设计、制备经济环保的纳米氧化铁固相催化剂，进而构建绿色、稳定的异相光芬顿体系，最终实现水中双酚S的高效去除。
首先，针对氧化铁实心颗粒所存在的比表面积小、活性点位暴露少等问题，本研究提出了“二氧化硅软模板”合成策略，实现了氧化铁中空球的温和、可控制备。在此基础上，阐明了氧化铁中空球微观结构-物化特性-光芬顿活性三者间的内在关系。三次循环降解实验表明，优选出氧化铁异质中空球的耐用性和持久性较好。经典的捕获剂实验结果表明在该光芬顿体系中起主要氧化作用的活性氧物种分别为超氧自由基和羟基自由基。在可见光照射下，优选出的氧化铁异质中空球对双酚S的降解率为30%，高于实心氧化铁纳米颗粒（商业品）的3%。分析原因是异质氧化铁中空球具有较大的比表面积、发达的孔隙结构，因此有利于催化剂活性点位的充分暴露，进而产生活性物质，以实现双酚S的有效降解。
虽然通过中空化处理（即微观结构的物理优化）可提高氧化铁的比表面积和材料表面的活性点位的数量，但仍不足以克服氧化铁作为光催化剂所固有的本征缺陷，如光生电子-空穴易复合等问题。针对这个问题，本研究在合成制备氧化铁时原位引入具有超高迁移率的石墨烯，进而获得了不同形貌氧化铁/石墨烯复合催化剂。氧化降解实验表明氧化铁量子点/石墨烯复合催化剂的光芬顿活性最高。自由基捕获实验和荧光光谱数据表明该体系里起主要降解作用的活性物质为羟基自由基。在可见光照射下，优选出的氧化铁量子点/石墨烯复合催化剂对双酚S的去除率可达83%，高于氧化铁异质中空球的30%。分析原因是石墨烯的引入一方面可有效阻碍光生电子空穴的复合，另一方面二维石墨烯纳米片会对双酚S产生较为强烈的吸附作用（40%）。
为获得催化活性更高的氧化铁纳米材料，进一步提出了“二氧化硅水凝胶
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协助溶解重结晶”的合成策略，成功制备了（110）高能晶面暴露的氧化铁超薄纳米片。在可见光照射下，以氧化铁纳米片所构建的光芬顿体系对双酚S的去除率高达91%（注：吸附仅占3%），高于商业P25二氧化钛的56%，且远高于氧化铁纳米颗粒（合成品）的16.6%。分析原因是：
1）由于光生电子在（110）晶面的迁移率非常高，导致光生载流子的分离效果好，使得参与后续反应的光生电子数量增多；
2）氧化铁纳米片的厚度仅为3.2 nm，能有效克服光生空穴扩散路程短的缺陷（2–4 nm），使得参与后续反应的光生空穴数量增多；
3）由于催化剂具有超薄二维片层结构，使得其比表面积较大，活性点位的暴露较为充分。
最后，采用UPLC/MS对双酚S的降解产物进行了鉴定。结果表明双酚S 的降解产物主要有二羟基苯磺酸、羟基苯磺酸、3-烯丙氧基-1-丙磺酸和苯酚钠。据此，可推断羟基化是驱动双酚S分解的主要机制。
关键词：双酚S；氧化铁；非均相芬顿；中空球；高能晶面
Abstract
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Abstract
Due to its excellent physical and chemical stability, bisphenol S (BPS) has been regarded as an ideal substitute for BPA (bisphenol A). And it has been widely applied in the synthesis of macromolecular materials such as polycarbonates, epoxy resins, polyester resins, polysulfone, and so on. At the same time, it has also been ud for the production of thermal papers and food package. However, the physiological toxicity of BPS has been uncovered with in-depth study, which i
s similar to the physiological toxicity of BPA. Even more disturbing, the emergence of BPS in surface water has been reported frequently, which deliver a rious threat for the public heathy. Therefore, it is of great significance to remove BPS from the aqueous systems.
Compared with the conventional Fenton technology, homogeneous photo-Fenton technology has exhibited a better application promising. However, it still exist some problems such as strict operation parameters and large amounts of sludge. To address the issues, rational design and synthesis of a catalyst could be a key for building the high-performance heterogeneous photo-Fenton system for degradation of BPS. The primary results of this study can be found below:
(1) To address the issues of solid iron oxide (i.e., limited active sites), we have first developed a “soft”SiO2templating strategy for effective and controllable fabrication of hollow iron oxide nanostructures. And then, the relationships between micro-structure and physicochemical property and photo-Fenton activity have been illuminated. Recycle catalytic tests have shown that the hierarchical hollow iron oxide nanospheres possd an excellent stability. The mechanic studies have indicated that the dominate active species are the superoxide radicals and hydroxyl radicals. 30% BPS can be degraded by the iron oxide hollow nanospheres under visible light irradiation, which is much higher than that of the solid iron oxide nanoparticles (3%). This excellent photo-Fento
n activity could be attributed to the high surface area and well-developed pore structure, thus leading to the effective degradation of BPS.
(2) Despite the higher surface area leading to better photo-Fenton activity, the inherent defects of iron oxide (e.g., rapid recombination of photo-excited carries) still exist. Therefore, graphene with a super-high migration rate has been introduced into the synthesis of iron oxide, thus obtaining the iron oxide/graphene composite materials. The degradation tests of rhodamine B have shown that the iron oxide quantum dots/graphene composite catalysts exhibit a better photoreactivity. The mechanic studies have indicated that the primary active species are the hydroxyl radicals. 83% of BPS can be degraded by the iron oxide quantum dots/graphene composite catalysts under visible light irradiation, which is much higher than that of
the s hierarchical hollow iron oxide nanospheres (30%). This excellent photo-Fenton activity could be attributed to the synergistic coupling effects in the samples: 1) 2D graphene sheets could be regarded as ideal conductive substrates, which may improve the electron transport; 2) graphene have an excellent ability to absorb the BPS from the water.
(3) To achieve the materials with a better catalytic activity, a silica hydrogel-mediated dissolution-recrystallization strategy has been propod for the fabrication of ultrathin iron oxide nanosheets with a high percentage of expod (110) facets. As high as 91% of BPS can be degraded by the iron oxide nanosheets under visible light irradiation, which is higher than that of P25 titanium dioxide (56%) and the iron oxide nanoparticles (16.6%). This outstanding photo-Fenton activity could be attributed to the advantageous properties of iron oxide nanosheets such as efficient charge paration and high surface area, which stem from the rationally designed nanoarchitectures of iron , ultrathin (~3.2 nm) sheet-like nanostructures with a high percentage of (110) facets). At last, the degradation byproducts of BPS have been identified and the corresponding transformation pathways have also been propod.
Keywords:bisphenol S, iron oxide, heterogeneous Fenton, hollow nanosphere, high-energy facet做鱼丸的正确配方
目录
摘要 ......................................................................................................................... I ABSTRACT ............................................................................................................. III 目录 ........................................................................................................................ IX 第1章绪论 .. (1)
黄果树瀑布作文
1.1内分泌干扰物 (1)
1.2双酚A (2)
1.2.1 双酚A的基本性质与用途 (2)
1.2.2 双酚A在环境中污染现状 (3)
1.2.3 双酚A潜在的危害 (4)
1.3双酚S (6)
1.3.1 双酚S的基本理化性质与用途 (6)
1.3.2 双酚S在环境中污染现状 (7)
1.3.3 双酚S潜在的危害 (10)
1.4可见光催化技术 (11)
1.4.1 氧化铁可见光催化技术 (11)
1.4.2 氧化铁可见光芬顿技术 (14)
1.5课题研究的目的、意义与内容 (15)
第2章实验材料与方法 (18)
2.1实验材料 (18)
2.1.1 实验药品 (18)
2.1.2 实验仪器 (18)
2.2物化性质表征 (20)
2.2.1 微观形貌分析 (20)
2.2.2 元素组成与价态分析 (20)清除电脑垃圾
2.2.3 晶型结构分析 (20)
2.2.4 组织结构分析 (20)
2.2.5 表面官能团分析 (20)
2.2.6 材料表面电荷分析 (21)
2.3催化剂的合成方法 (21)
药品市场营销2.3.1 氧化铁中空球的制备 (21)
2.3.2 氧化铁/石墨烯复合催化剂的制备 (21)日本美妆品牌
