【作者】 张玉；

【导师】 陈星；

【作者基本信息】 合肥工业大学 ， 材料工程（专业学位）， 2022， 硕士

【摘要】 近年来,抗生素的过量使用对人类健康和生态系统可能会产生一定的负面影响,这些影响受到了越来越多的关注。目前,抗生素污染的处理主要通过吸附、膜分离、高级氧化等技术实现,但这些技术分别存在材料重复利用率低、膜污染严重、p H范围窄等问题。光催化技术具有绿色、高效低成本等特点,但光催化剂在合成与应用时易产生团聚问题,从而导致其催化活性降低,通过将其与载体材料的复合有望提高光催化技术的稳定性与实用性。硅藻土（DE）作为一种稳定的、多孔的、廉价的天然矿物材料,是负载光催化剂的理想载体之一。本文以经预处理的硅藻土作为载体,分别采用热聚合法和溶剂热法合成了两种不同的硅藻土基复合光芬顿催化剂,借助系列表征对两种催化剂的形貌、表面官能团及表面化学性质等进行了细致研究;以抗生素为目标污染物研究了两种催化剂的光芬顿催化性能。并结合自由基捕获实验等手段分析了两种催化剂在光芬顿催化过程中的活性物质及可能的降解机理。具体研究内容和结果如下:（1）利用热聚合法制备出不同含量Fe掺杂Fe-g-C₃N₄/DE复合催化剂,通过系列表征得出,硅藻土作为载体,有效地避免了g-C₃N₄的团聚,Fe的掺杂改善了催化剂表面的电子结构,使得催化剂对盐酸四环素（TC）表现出优异的催化性能。光催化降实验结果表明:FGD-3催化剂在可见光和H₂O₂的协同催化作用下,可见光照射100 min,p H值为4、H₂O₂浓度为1 mmol/L和TC初始浓度为20 mg/L时,降解率可以达到98.3%。催化剂在重复5次实验后表现出良好的稳定性;自由基捕获实验表明该光芬顿催化体系中起主要作用的是h⁺。（2）利用溶剂热法制备出硅藻土负载羟基改性的锆基金属有机框架催化剂（HO-UIO-66/DE）,对催化剂进行不同温度的煅烧处理,研究其对磺胺甲噁唑（SMX）的光芬顿催化降解性能。材料表征结果表明:催化剂成功地负载到硅藻土表面,羟基的引入有效地改善了催化剂对可见光的吸收性能。同时,随着煅烧温度的升高,催化剂的稳定性得到有效改善,但催化性能有所下降。煅烧温度为300℃条件下所得的催化剂（HO-UIO-66/DE-300）具有良好的稳定性和催化性能:单因素实验发现,HO-UIO-66/DE-300在可见光和H₂O₂的协同催化作用下,H₂O₂浓度为4 mmol/L、p H值为3,SMX污染物初始浓度为20 mg/L时,可见光照射120 min降解率达到93.8%。自由基捕获实验和ESR表征发现,h⁺是该体系中主要活性物种,同时¹O₂、·O₂^-和·OH在反应中也起到重要的作用。更多还原

【Abstract】 In recent years,the excessive use of antibiotics may have some negative effects on human health and ecosystems,these effects were more and more attention.At present,antibiotics wastewater is mainly treated by adsorption,membrane separation,advanced oxidation and other technologies,However,these technologies have some problems,such as low material reuse rate,serious membrane pollution and narrow pH range and so on.Photocatalysis technology has the characteristics of green,high efficiency and low cost,but it is easy to produce agglomeration problems in the synthesis and application of photocatalyst,which leads to the reduction of its catalytic activity.The combination of photocatalyst and carrier material is expected to improve the stability and practicability of photocatalysis technology.As a stable,porous and cheap natural mineral material,diatomite（DE）is one of the ideal carriers for photocatalyst.In this paper,pretreated diatomite was used as the carrier.Two different diatomite-based composite photo-Fenton catalysts were synthesized by thermal polymerization and solvothermal method respectively.The surface morphology,surface functional groups and surface chemical properties of the two catalysts were studied utilizing various characterizations.Taking antibiotics as target pollutants,the photocatalytic properties of the two catalysts were studied.The active substances and possible degradation mechanism of the two catalysts in the process of photo-Fenton catalysis were analyzed by an active radical scavenging experiment.The specific contents and discussions are as follows:（1）Fe-g-C₃N₄/DE composite catalyst with different Fe doping content was prepared by thermal polymerization.With the help of characterization,it is found that diatomite as the carrier can effectively avoid the agglomeration of g-C₃N₄,and Fe doping improves the electronic structure of the catalyst surface so that the catalyst has excellent catalytic performance for tetracycline hydrochloride（TC）.Photocatalytic degradation experiment results show that under the synergistic catalysis of visible light and H₂O₂,the degradation rate of FGD-3 catalyst can reach 98.3%when 1mmol/L H₂O₂ at pH 4and the initial concentration of TC is 20 mg/L.The catalyst showed good stability after repeated use 5 times.The active radicals capture experiments show that h⁺plays a major role in the photo-Fenton catalytic system.（2）Diatomite-supported hydroxyl modified zirconium-based metal-organic framework catalyst（HO-UIO-66/DE）was prepared using the solvothermal method.The catalyst was calcined at different temperatures to study its photocatalytic degradation performance of sulfamethoxazole（SMX）.The results of material characterization showed that the catalyst was successfully loaded on the surface of diatomite,and the introduction of the hydroxyl group effectively improved the visible light absorption performance of the catalyst.At the same time,with the increase in calcination temperature,the stability of the catalyst was effectively improved,but the catalytic performance decreased.The catalyst（HO-UIO-66/DE-300）obtained at the calcination temperature of 300℃ has good stability and catalytic performance:the single factor experiment shows that under the synergistic catalysis of visible light and H₂O₂ when the concentration of H₂O₂ is 4 mmol/L,the p H value is 3,and the initial concentration of SMX pollutant is 20 mg/L,the degradation rate of HO-UIO-66/DE-300 under visible light irradiation for 120 min reaches 93.8%.Through active radical scavenging experiment and ESR characterization,it is found that h⁺is the main active species in the system,and ¹O₂,·O₂^-and·OH also play an important role in the reaction.更多还原