本文選題：g-C_3N_4　切入點(diǎn)：鹵代氨基苯腈　出處：《鄭州大學(xué)》2017年碩士論文　論文類(lèi)型：學(xué)位論文

【摘要】：自2009年石墨相氮化碳g-C_3N_4首先被Wang等人作為光催化劑用于光解水制氫以來(lái),作為可見(jiàn)光驅(qū)動(dòng)的催化劑,g-C_3N_4引起了眾多研究者的興趣。g-C_3N_4作為非金屬光催化劑具有諸多優(yōu)點(diǎn),如合適能帶結(jié)構(gòu)、易修飾、廉價(jià)等。但是g-C_3N_4光吸收范圍窄、光電效率低等缺點(diǎn)仍然制約著其光催化性能的提高。針對(duì)g-C_3N_4的這些缺陷,本文主要從形貌調(diào)控、離子摻雜和共聚合改性幾個(gè)方面開(kāi)展工作,對(duì)g-C_3N_4進(jìn)行改性。利用XRD、FTIR、SEM、UV-Vis DRS等手段對(duì)改性材料進(jìn)行結(jié)構(gòu)性質(zhì)表征,并通過(guò)光催化制氫性能測(cè)試評(píng)價(jià)改性材料的光催化活性。主要工作內(nèi)容如下:(1)利用氨基和腈基的親電/親核加成反應(yīng),以鹵代氨基苯腈為共聚單體,制備了鹵代氨基苯腈共聚合改性的氮化碳材料:F-CN、Cl-CN、Br-CN和I-CN。表征分析發(fā)現(xiàn),鹵代氨基苯腈共聚合改性的g-C_3N_4保持了本體g-C_3N_4的基本化學(xué)結(jié)構(gòu)與形貌特征,但改性材料的光電性能有所提升。I-CN的XPS圖譜中發(fā)現(xiàn)I 3d峰證明了含碘基團(tuán)接入氮化碳分子骨架中。在負(fù)載4wt%Pt、可見(jiàn)光的照射下,F-CN、Cl-CN、Br-CN、I-CN的光催化制氫效率分別為41.46μmol·h-1、49.12μmol·h-1、55.35μmol·h-1和84.15μmol·h-1。相較于本體g-C_3N_4的13.62μmol·h-1均有提高,且按照鹵素原子序數(shù)的增加而提高。其中I-CN制氫效率約是g-C_3N_4的6.18倍。主要原因是I-CN功能基團(tuán)電負(fù)性相較于本體g-C_3N_4最低,提高了光電效率。同時(shí),碘離子也可能同時(shí)對(duì)g-C_3N_4進(jìn)行離子摻雜改性,產(chǎn)生共聚合改性與離子摻雜的共同作用,提高了其催化活性。再者I-CN光電流大約為g-C_3N_4的2倍。(2)利用HS-40水溶性硅膠,對(duì)氮化碳進(jìn)行形貌調(diào)控,制備多孔共聚合改性氮化碳材料:g-MCN、F-MCN、Cl-MCN、Br-MCN和I-MCN,表征分析發(fā)現(xiàn)多孔材料相對(duì)于g-C_3N_4光電性能進(jìn)一步增強(qiáng)。在可見(jiàn)光照射下,多孔的鹵代氨基苯腈共聚合改性g-C_3N_4制氫性能大幅度的提高,在負(fù)載4wt%Pt、可見(jiàn)光的照射下I-MCN樣品產(chǎn)氫效率最高,可達(dá)到109.12μmol·h-1,高于未經(jīng)模板造孔的樣品I-CN的84.12μmol·h-1,約達(dá)到本體g-C_3N_4的8.3倍。這是因?yàn)樵诠簿酆细男缘幕A(chǔ)上,I-MCN產(chǎn)生了孔結(jié)構(gòu),增加了比表面積。
[Abstract]:Since 2009, when graphite-phase carbon nitride g-C _ 3N _ 4 was first used by Wang and others as photocatalyst for the production of hydrogen by photolysis of water, it has attracted many researchers' interest. G-C _ 3N _ 4 has many advantages as a non-metallic photocatalyst. Such as suitable band structure, easy modification, low cost, etc. However, the disadvantages of g-C _ 3N _ 4, such as narrow optical absorption range and low photoelectric efficiency, still restrict the improvement of its photocatalytic performance. The modification of g-C _ 3N _ 4 was carried out in several aspects of ion doping and copolymerization modification. The structure and properties of the modified materials were characterized by means of XRD-FTIR, SEMI-UV-Vis DRS, etc. The photocatalytic activity of the modified materials was evaluated by photocatalytic hydrogen production performance test. The main work was as follows: 1) using the electrophilic / nucleophilic addition reaction of amino and nitrile groups, halogenated aminobenzonitrile was used as the copolymerization monomer. Carbon nitride modified by halogenated aminobenzonitrile was prepared. It was found that g-C _ 3N _ 4 modified by the copolymerization of halogenated aminobenzonitrile maintained the basic chemical structure and morphology of g-C _ 3N _ 4, which was modified by the copolymerization of halogenated aminobenzonitrile. However, the I 3D peak of the modified materials was found in the XPS spectra of the modified materials. It was proved that the iodide-containing group was inserted into the carbon nitride molecular skeleton. The photocatalytic hydrogen production efficiency of F-CNCCl-CN-CN-CN-CNI-CN was 41.46 渭 mol 路h-1h-19.12 渭 mol 路h-1h-55.35 渭 mol 路h-1 and 84.15 渭 mol 路h-1, respectively, under the irradiation of 4wt Pt.The results showed that the photocatalytic efficiency of the modified materials was 41.46 渭 mol 路h-1h-1h-1h-55.35 渭 mol 路h-1 and 84.15 渭 mol 路h-1, respectively. Compared with the noumenon g-C3Ns 4, the 13.62 渭 mol 路h-1 of the tipping-C _ 3Ns _ 4 was increased, The hydrogen production efficiency of I-CN is about 6.18 times that of g-C _ 3N _ 4. The main reason is that the electronegativity of I-CN functional group is lower than that of g-C _ 3N _ 4, which improves the photoelectric efficiency. It is also possible that iodide ion can also doping g-C _ S _ 3N _ 4, resulting in the co-effect of copolymerization modification and ion doping, which enhances its catalytic activity. Furthermore, the photocurrent of I-CN is about twice that of g-C _ S _ 3N _ 4) using HS-40 water-soluble silica gel. The morphology of carbon nitride was regulated and the porous copolymerization modified carbon nitride materials were prepared. The results of characterization analysis showed that the optoelectronic properties of the porous materials were further enhanced compared with those of g-C _ 3N _ 4. Under visible light irradiation, the porous materials were better than g-C _ 3N _ 4. The hydrogen production performance of g-C _ 3N _ 4 modified by porous halogenated aminobenzonitrile was greatly improved, and the hydrogen production efficiency of I-MCN sample was the highest under the irradiation of 4wt Ptand visible light. It can reach 109.12 渭 mol 路h-1, which is 84.12 渭 mol 路h-1 of I-CN, which is about 8.3 times that of bulk g-C3N4. This is due to the formation of pore structure and the increase of specific surface area of I-MCN on the basis of copolymerization modification.
【學(xué)位授予單位】：鄭州大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：TQ116.2;O643.36

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相關(guān)期刊論文 前1條

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本文編號(hào)：1591975