本文選題：量子 + 修飾　； 參考：《江蘇大學(xué)》2017年碩士論文

【摘要】：偶氮染料是當(dāng)今種類最多、使用最廣泛的一類染料。但是在生產(chǎn)和應(yīng)用過程中,高達(dá)10%-15%的染料未經(jīng)處理就被排放到環(huán)境中,對人類的生活和健康造成了巨大威脅。因此,排放前對其進(jìn)行無害化處理是目前控制偶氮染料廢水污染的最好方法。目前,傳統(tǒng)的處理偶氮染料廢水的方法效果不佳,在處理偶氮染料污染的同時(shí),可能會(huì)造成更為嚴(yán)重的環(huán)境危機(jī)(例如活性泥法,在厭氧條件下可能會(huì)生成對人類危害更大的芳香胺類物質(zhì))。因此,人們迫切需要尋找一種高效、清潔、可持續(xù)的方法來解決偶氮染料廢水問題。在這種背景下,半導(dǎo)體光催化技術(shù)走進(jìn)了人們的視野。然而光生電子-空穴對分離不徹底、電子和空穴復(fù)合率高等缺點(diǎn)在一定程度上限制了單一半導(dǎo)體光光催化劑的活性。為了解決上述問題,該工作選用一種新型的納米碳材料(碳量子點(diǎn))來修飾半導(dǎo)體光催化劑,希望能夠大幅度的提升其對偶氮染料(甲基橙)的光催化降解活性。具體研究內(nèi)容如下:(1)CQDs/ZnFe_2O_4復(fù)合材料是通過一種簡單的超聲波輔助法制備的。各種表征結(jié)果顯示:ZnFe_2O_4微球被低對比度的碳量子點(diǎn)層包覆,形成了一種核殼結(jié)構(gòu)。為了研究CQDs/Zn Fe_2O_4復(fù)合材料的光催化性能,我們以制備的復(fù)合材料為催化劑進(jìn)行了光催化降解亞甲基藍(lán)的研究,結(jié)果表明:當(dāng)碳量子點(diǎn)的負(fù)載量為20%(質(zhì)量分?jǐn)?shù))時(shí),CQDs/ZnFe_2O_4復(fù)合材料的光催化性能最優(yōu),大約是純Zn Fe_2O_4樣品的5.9倍�；诠腆w紫外-可見吸收、熒光、阻抗等分析結(jié)果,我們提出了光催化活性提高的可能機(jī)理。(2)通過一步水熱法合成了一種新型的碳量子點(diǎn)修飾In_2S_3微球光催化劑,與純In_2S_3相比,該催化劑表現(xiàn)出優(yōu)異的偶氮染料降解活性(120 mim內(nèi)可以實(shí)現(xiàn)對甲基橙近90%的光催化降解)。通過大量的實(shí)驗(yàn)和表征,我們發(fā)現(xiàn):碳量子點(diǎn)修飾In_2S_3微球光催化劑具有優(yōu)異的光催化活性的主要原因是碳量子點(diǎn)的上轉(zhuǎn)換熒光功能和優(yōu)異的電子轉(zhuǎn)移能力。基于捕獲實(shí)驗(yàn)、電子順磁共振分析、紫外-可見吸收和理論計(jì)算可以確定·O2-和h+是光催化過程中的主要活性物種,進(jìn)而提出了可能的光催化降解機(jī)理。(3)該部分工作主要研究CQDs/Bi4O5I2復(fù)合材料在可見光下降解偶氮染料甲基橙的性能。為了更好的突出碳量子點(diǎn)修飾半導(dǎo)體光催化劑用于光催化降解偶氮染料廢水的優(yōu)勢,我們選取并制備最具代表性的Bi2S3/Bi4O5I2復(fù)合材料與
[Abstract]:Azo dyes are the most widely used dyes in the world.However, in the process of production and application, up to 10- 15% of the dyes are discharged into the environment without treatment, which poses a great threat to human life and health.Therefore, it is the best way to control the pollution of azo dye wastewater before discharge.At present, the traditional treatment of azo dye wastewater is not effective, while the treatment of azo dye pollution may cause a more serious environmental crisis (such as reactive sludge process,Under anaerobic conditions, aromatic amines may be produced that are more harmful to humans.Therefore, there is an urgent need to find an efficient, clean and sustainable way to solve the azo dye wastewater problem.In this context, semiconductor photocatalytic technology into the field of vision.However, the separation of photogenerated electron-hole pairs is not complete, and the high recombination rate of electrons and holes limits the photocatalytic activity of a single semiconductor photocatalyst to some extent.In order to solve the above problems, a new nano-carbon material (carbon quantum dot) was chosen to modify the semiconductor photocatalyst. It is hoped that the photocatalytic degradation activity of azo dyes (methyl orange) can be greatly improved.The specific research contents are as follows: CQDs / ZnFe2O4 composites were prepared by a simple ultrasonic assisted method.The results show that the microspheres are coated with low contrast carbon quantum dots to form a core-shell structure.In order to study the photocatalytic properties of CQDs/Zn Fe_2O_4 composites, the photocatalytic degradation of methylene blue was studied.The results show that the CQDs / ZnFe2O4 composite has the best photocatalytic performance when the loading amount of carbon quantum dots is 20 (mass fraction), which is about 5.9 times as high as that of pure Zn Fe_2O_4.Based on the results of solid UV-Vis absorption, fluorescence and impedance analysis, we proposed a possible mechanism for the improvement of photocatalytic activity. A novel carbon quantum dot-modified In_2S_3 microsphere photocatalyst was synthesized by a one-step hydrothermal method. Compared with pure In_2S_3, a new type of photocatalyst was synthesized.The catalyst showed excellent degradation activity of azo dyes and could achieve nearly 90% photocatalytic degradation of methyl orange within 120 mim.Through a large number of experiments and characterization, we found that the main reasons for the excellent photocatalytic activity of carbon quantum dots modified In_2S_3 microspheres are the up-conversion fluorescence function and the excellent electron transfer ability of carbon quantum dots.Based on capture experiments, electron paramagnetic resonance analysis, UV-Vis absorption and theoretical calculations, it can be concluded that O _ 2- and h are the main active species in photocatalytic process.Furthermore, the possible photocatalytic degradation mechanism was proposed. (3) the main work of this part was to study the degradation of azo dye methyl orange by CQDs/Bi4O5I2 composites under visible light.In order to better highlight the advantages of carbon quantum dot-modified semiconductor photocatalysts for photocatalytic degradation of azo dye wastewater, we selected and prepared the most representative Bi2S3/Bi4O5I2 composites.
【學(xué)位授予單位】：江蘇大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：X791;O643.36

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