本文關(guān)鍵詞：類石墨烯與鈰氧化物復(fù)合的制備、結(jié)構(gòu)及性能研究　出處：《深圳大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 類石墨烯 鈰氧化物 包覆 光催化

【摘要】：稀土金屬獨特的4 f電子構(gòu)型使其具有優(yōu)異的光學(xué)、電學(xué)、磁學(xué)性能。其中,鈰氧化物尤為受到人們的廣泛關(guān)注。Ce有Ce4+和Ce3+兩種價態(tài)氧化物,兩種價態(tài)轉(zhuǎn)變中的氧化還原電勢極低,鈰可以在Ce4+和Ce3+兩種氧化態(tài)之間迅速變化,發(fā)生氧化還原循環(huán),因此具有較強的儲備功能。Ce2O3屬于立方晶系。Ce O2作為功能材料具備Ca F2的面心立方(FCC)螢石結(jié)構(gòu)以及較高的氧空位濃度,這使其具有高效光催化和優(yōu)異的電化學(xué)性能,尤其在多相催化領(lǐng)域中Ce O2表現(xiàn)出獨特的儲放氧能力。近年來,石墨烯基復(fù)合材料受到了人們的廣泛關(guān)注。石墨烯基納米復(fù)合材料不僅可保留石墨烯作為基體材料和負載材料的原始性能與優(yōu)點,而且能夠產(chǎn)生新的協(xié)同作用。石墨烯片的獨特二維結(jié)構(gòu)有助于高效地將半導(dǎo)體催化劑固定在其表面,將鈰氧化物如Ce O2負載在石墨烯上形成的復(fù)合材料有望表現(xiàn)出更為優(yōu)異的性能。因此,本論文首次將二氧化鈰粒子負載到本實驗室自制的液態(tài)聚丙烯腈低聚物(Liquid Acrylonitrile Oligomer,LANO)表面,將Ce O2與LANO(高溫后結(jié)構(gòu)轉(zhuǎn)變?yōu)轭愂┢瑢咏Y(jié)構(gòu))進行機械混合再燒結(jié)之后得到類石墨烯/鈰氧化物(Ceria oxides/graphene-like,COGL)(其中包含Ce(Ⅲ)氧化物與Ce(Ⅳ)氧化物)納米復(fù)合粒子。論文主要內(nèi)容如下:1.通過液相球磨法制備了類石墨烯/鈰氧化物(COGL)復(fù)合材料,研究了不同溫度下(包括800℃、1000℃、1200℃、1300℃、1400℃以及1500℃)制備得到的COGL納米復(fù)合粒子的形貌、結(jié)構(gòu)與燒結(jié)溫度的關(guān)系,通過不斷優(yōu)化工藝流程得到形貌、結(jié)構(gòu)可控的COGL納米復(fù)合材料;2.利用SEM、TEM及XRD對COGL納米復(fù)合粒子的形貌和晶型構(gòu)成等進行了表征。結(jié)果表明:在1300℃以下溫度燒結(jié),LANO交聯(lián)環(huán)化得到的碳石墨化程度較低,主要為無定形碳。且此時LANO不能將+4價鈰氧化物還原。當(dāng)溫度升高至1500℃時,Ce含量較低時可制備得到Ce C2/C復(fù)合粒子,該粒子具有較強的抗氧化性。當(dāng)Ce含量高時可制備得到Ce(Ⅲ)氧化物/類石墨烯復(fù)合粒子,并且隨著溫度升高粒子半徑減小。光電子能譜結(jié)果顯示1500℃的COGL90復(fù)合物表面存在+3鈰氧化物存在,說明Ce O2存在氧空位。Raman光譜表明,當(dāng)溫度高于1300℃時,COGL中碳的石墨化程度較高。隨著溫度的提高,碳的石墨化程度進一步加強;3.對制備的COGL納米復(fù)合粒子進行光催化降解實驗。結(jié)果表明,無Ce O2的空白對照組在紫外光下照射360mins幾乎沒有表現(xiàn)出任何催化性能,純Ce O2作為光催化劑在同樣條件下,其降解率達到4.9%,表明Ce O2在紫外光照射下具有一定的光催化降解作用;而COGL作為光催化劑催化亞甲基藍降解的速率明顯加快,隨著Ce O2含量的提高,COGL的光催化效率逐漸提高。對于相同含量的COGL納米復(fù)合粒子,隨著燒結(jié)溫度的提高,COGL的光催化效率逐漸提高。這些結(jié)果表明COGL納米復(fù)合粒子具有良好的光催化活性。COGL中的類石墨烯作為光催化反應(yīng)的電子運載通道和電子受體對于COGL納米復(fù)合粒子的光催化活性起著重要作用。
[Abstract]:Rare earth metal 4 unique f electron configuration which has excellent optical, electrical and magnetic properties. Among them, cerium oxide is widely concerned by people especially.Ce Ce4+ and Ce3+ two kinds of valence oxide, two valence transition in redox potential is extremely low, cerium can quickly change between Ce4+ and Ce3+ two an oxidation state, the redox cycle, so it has strong reserve function.Ce2O3 belongs to cubic.Ce O2 as FCC functional materials with Ca F2 (FCC) fluorite structure and higher concentration of oxygen vacancy, which makes it a highly efficient photocatalytic and excellent electrochemical performance, especially in the field of heterogeneous catalysis Ce O2 displays the unique oxygen storage capacity. In recent years, graphene based composite materials have attracted much attention. The graphene nanocomposites can retain graphene as the substrate material and the material of the original load Performance and advantages, but also can produce new synergy. The unique two-dimensional structure of graphene contributes to efficient semiconductor catalyst fixed on its surface, the cerium oxides such as Ce O2 load composite material formed on graphene is expected to exhibit more excellent properties. Because of this, this paper for the first time two cerium oxide particles supported the self-made liquid polyacrylonitrile (Liquid Acrylonitrile Oligomer LANO, oligomer) surface, O2 and LANO (Ce after high temperature structure of graphene layer structure) after mechanical mixing and sintering to graphene / cerium oxide (Ceria oxides/graphene-like, COGL (including Ce () III) oxide and Ce (IV) oxide) nano composite particles. The main contents are as follows: 1. by liquid phase milling of graphene / cerium oxide was prepared (COGL) composites were investigated at various temperatures (pack The 800 C, 1000 C, 1200 C, 1300 C, 1400 C and 1500 C) morphology of COGL nano composite particles prepared by the relationship between the structure and the sintering temperature, through continuous optimization process were obtained, COGL nano composite structure controlled by SEM; 2., morphology and crystal structure of COGL nano composite the TEM and XRD particles were characterized. The results show that the sintering temperature is below 1300 DEG C, the graphitization degree of carbon LANO cross-linking obtained is low, mainly for the amorphous carbon and the LANO can not be +4 valence cerium oxide reduction. When the temperature rises to 1500 degrees, with low Ce content can be prepared by Ce C2/C composite particles, the particles have strong antioxidant activity. When the content of Ce is prepared by Ce (III) oxide / graphene composite particles, and the particle radius decreases with the increase of temperature. The XPS results showed that 1500 DEG COGL90 composite The surface of existing +3 cerium oxides, Ce O2 oxygen vacancies.Raman spectra show that when the temperature is higher than 1300 DEG C, COGL carbon in high graphitization degree. With the increase of temperature, the graphitization degree of carbon reinforced; 3. COGL nano composite particles were prepared by photocatalytic degradation experiments. The results showed that no Ce O2, blank control group under UV light irradiation 360mins almost did not show any catalytic properties of pure Ce O2 as photocatalyst under the same conditions, the degradation rate reached 4.9%, Ce showed that O2 has certain effects on photocatalytic degradation under UV irradiation; and COGL is the rate of catalytic degradation of methylene blue light catalyst with Ce increased significantly, the content of O2 increased, the photocatalytic efficiency of COGL increased gradually. The COGL nanoparticles content is the same, with the increase of sintering temperature, the photocatalytic activity of COGL was gradually increased. These results indicate that COGL nanocomposite particles have good photocatalytic activity. Graphene in.COGL plays an important role in the photocatalytic activity of COGL nanocomposite particles as the electron transport channel and electron acceptor of photocatalytic reaction.

【學(xué)位授予單位】：深圳大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TB332

【參考文獻】

相關(guān)期刊論文 前3條

1 Lei Ma;Aiping Chen;Jindong Lu;Zhe Zhang;Hongbo He;Chunzhong Li;;In situ synthesis of CNTs/Fe-Ni/TiO_2 nanocomposite by fluidized bed chemical vapor deposition and the synergistic effect in photocatalysis[J];Particuology;2014年03期

2 鄒興,盧惠民,方克明;變價稀土氧化物對催化劑性能的影響[J];稀土;2000年02期

3 宋啟祥;王桂英;嚴國清;毛強;王聞琦;彭振生;;Influence of the substitution of Sm, Gd, and Dy for La in La_(0.7)Sr_(0.3)MnO_3 on its magnetic and electric properties and strengthening effect on room-temperature CMR[J];Journal of Rare Earths;2008年06期

相關(guān)碩士學(xué)位論文 前1條

1 李光達;碳納米材料及其復(fù)合材料的合成與表征[D];山東大學(xué);2009年

，

本文編號：1384371