本文選題：還原氧化石墨烯 + 凝膠��； 參考：《哈爾濱工業(yè)大學》2017年碩士論文

【摘要】：納米粒子(NPs)相對于體狀材料具有優(yōu)異的催化性質(zhì),在治理環(huán)境污染和解決能源危機方面具有潛在應用。但是催化反應過程中NPs易團聚,從而使比表面積下降,降低其催化活性。因此,一般將NPs負載到合適的催化劑載體。石墨烯具有高電子遷移率、大表面積、高機械性能和特有的吸附性,是理想的催化劑載體。氧化石墨烯常常用作石墨烯的前驅(qū)體。石墨烯納米片之間往往容易團聚和堆疊,加上僅僅依靠傳統(tǒng)的化學氧化技術無法徹底降解污染物�；谝陨峡紤],本文介紹了一種將二維(2D)氧化石墨烯納米片(GS)組裝成三維(3D)還原氧化石墨烯(r GS)凝膠的簡便方法,不僅增大催化劑的表面積,而且可以提高NPs的分散性并減小粒徑,從而提高催化劑的催化活性。而且借助于凝膠分級多孔結(jié)構(gòu)的物理吸附作用,加快反應溶液的傳質(zhì)和擴散。這樣,物理吸附和化學氧化技術相結(jié)合,可以提高污染物的降解速率。另外,引入磁性納米粒子及采用雙重載體保護,可以減少催化劑流失,從而改善凝膠材料的循環(huán)利用性。具體研究內(nèi)容包括以下三部分:(1)采用“一步法”制備r GS/Fe_2O_3/聚吡咯(PPy)三元凝膠。通過不同材料形貌對比,研究凝膠形成機理。以H_2O_2降解亞甲基藍(MB)的Fenton反應作為模型反應測試材料的催化性能,隨著催化劑用量增加、MB濃度降低、一定范圍內(nèi)H_2O_2用量的增加,MB降解速率加快。另外,催化劑有磁性,易分離。經(jīng)過4次循環(huán)催化,催化活性仍未有明顯降低。(2)采用“一步法”將PdPt合金負載于r GS凝膠制備出r GS/Fe_2O_3-Pd Pt/PPy五元凝膠。經(jīng)過冷凍干燥,五元凝膠呈分級多孔結(jié)構(gòu),對染料的吸附效果優(yōu)于烘干凝膠,并且PdPt合金粒子分布均勻且粒徑極小,在Na BH4還原對硝基苯酚(4-NP)的反應中表現(xiàn)出優(yōu)異的催化性能。(3)采用“兩步法”制備r GS/Fe_2O_3/氮摻雜碳納米片(NCS)凝膠材料。對凝膠的形貌結(jié)構(gòu)及組分進行分析表征,并將該材料用于催化光Fenton反應降解羅丹明B(Rh B)。由于凝膠的吸附作用與Fe_2O_3的高催化活性協(xié)同,Rh B降解速率很快。同時,Fe_2O_3有磁性,催化劑能通過外加磁場分離,并具有較好的循環(huán)使用性。
[Abstract]:Nanoparticles (NPs) have excellent catalytic properties compared with bulk materials and have potential applications in environmental pollution control and energy crisis resolution. However, NPs is easy to agglomerate during catalytic reaction, which decreases the specific surface area and reduces its catalytic activity. Therefore, NPs is generally supported on the appropriate catalyst carrier. Graphene is an ideal catalyst carrier with high electron mobility, large surface area, high mechanical properties and unique adsorption. Graphene oxide is often used as a precursor of graphene. Graphene nanoparticles are often easy to agglomerate and stack, and traditional chemical oxidation techniques alone can not completely degrade pollutants. Based on the above considerations, this paper introduces a simple method of assembling two-dimensional graphene oxide (2-D) graphene oxide (GSN) into a three-dimensional (3D) reductive graphene oxide (GSR) gel, which not only increases the surface area of the catalyst, but also increases the surface area of the catalyst. Moreover, the dispersion of NPs can be improved and the particle size can be reduced, thus the catalytic activity of the catalyst can be improved. The mass transfer and diffusion of the reaction solution were accelerated by the physical adsorption of the porous structure of the gel. In this way, the combination of physical adsorption and chemical oxidation can improve the degradation rate of pollutants. In addition, the introduction of magnetic nanoparticles and double carrier protection can reduce the loss of catalyst and improve the recycling performance of gel materials. The specific research contents include the following three parts: 1) preparation of r GS/Fe_2O_3/ polypyrrole pyrrolidine ternary gel by "one step method". The gel formation mechanism was studied by comparing the morphology of different materials. The Fenton reaction of H_2O_2 degradation of methylene blue blue (MBB) was used to test the catalytic performance of the model reaction material. With the increase of the concentration of the catalyst, the degradation rate of MB was accelerated with the increase of the amount of H_2O_2 in a certain range. In addition, the catalyst is magnetic, easy to separate. After four cycles of catalysis, the catalytic activity was not significantly decreased. (2) r GS/Fe_2O_3-Pd Pt/PPy quaternary gel was prepared by "one step method" by loading PdPt alloy onto rGS gel. After freeze-drying, the five-component gel showed a hierarchical porous structure, and the adsorption effect of the dye was better than that of the drying gel, and the particle size of the PdPt alloy was very small, and the distribution of the particles was uniform. In the reduction of p-nitrophenol 4-NPs by Na BH4, excellent catalytic performance was obtained. (3) r GS/Fe_2O_3/ nitrogen-doped carbon nanoflake gel materials were prepared by "two-step method". The morphology, structure and composition of the gel were analyzed and characterized, and the material was used to catalyze the photodegradation of Rhodamine B(Rh B(Rh by photocatalytic Fenton reaction. Because of the adsorption of gel and the high catalytic activity of Fe_2O_3, the degradation rate of Rh B is very fast. At the same time, Fe2O3 is magnetic, the catalyst can be separated by external magnetic field, and has good recycling performance.
【學位授予單位】：哈爾濱工業(yè)大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TQ427.26;X703

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