本文選題：射線輻照方法 + MnO/rGO復(fù)合材料��； 參考：《中國科學(xué)技術(shù)大學(xué)》2017年碩士論文

【摘要】：由于獨特的光電性能、優(yōu)異的機(jī)械性能和高的比表面積,石墨烯有著非常廣泛的應(yīng)用。但由于石墨烯層間的范德華和π-π吸引力的作用,石墨烯易傾向于堆疊,而這則極大的抑制了石墨烯本身具有的優(yōu)異性能,限制了其在大多數(shù)領(lǐng)域的應(yīng)用。而石墨烯三維結(jié)構(gòu)和其納米復(fù)合材料因其獨特的結(jié)構(gòu)可以避免石墨烯層間的堆疊。目前石墨烯及其復(fù)合材料典型的合成方法包括氣相沉積法、化學(xué)還原法和水熱法等,但這些方法的應(yīng)用因為高昂的費用、有毒還原劑的使用及苛刻的高壓條件等被極大地限制。在本論文中,我們采用了一種溫和且潔凈的γ-射線輻照方法,對其在兩種石墨烯(復(fù)合)材料中的制備進(jìn)行了研究。一、在常溫常壓下,通過γ-射線輻照方法制備氧化亞錳/石墨烯(MnO/rGO)復(fù)合材料,用于鋰離子二次電池負(fù)極。γ-射線可以輻解水產(chǎn)生水合電子還原高錳酸鉀,產(chǎn)生尺寸可調(diào)的MnO顆粒,并在石墨烯的表面上均勻地分布。以上優(yōu)勢使γ-射線輻照還原制備的MnO/rGO復(fù)合材料有著較好的電化學(xué)性能。2 A g-1電流密度下進(jìn)行500次循環(huán)后,MnO/rGO復(fù)合材料的比容量仍可高達(dá)1687 mA h g-1。在0.2 Ag-1的高電流密度下,MnO/rGO復(fù)合材料的比容量可高達(dá)2175 mAh g-1。且即使在15 Ag-1的高電流密度下,復(fù)合材料的比容量仍可達(dá)546mAh g-1,約為商用石墨負(fù)極的1.5倍。因此,γ-射線輻照還原在制備電池材料方面將是一種很有前景的方法。二、在無表面活性劑的條件下,采用簡單的γ-射線輻射法合成石墨烯海綿結(jié)構(gòu)。通過在氧化石墨烯(GO)分散液中加入醋酸和氨水調(diào)節(jié)GO在溶劑中的分散狀態(tài),分析其對三維石墨烯海綿形成的影響。還通過在石墨烯上負(fù)載1.1×104 cm cm-2的CNT(5 wt.%)來增強(qiáng)石墨烯海綿的壓縮性能。我們也通過控制GO的濃度來調(diào)節(jié)石墨烯海綿的密度,以滿足不同的需求。石墨烯海綿的密度可低至5.0 mg cm-3,孔隙率高達(dá)99.8%,電導(dǎo)率僅為0.012 S cm-1。我們對海綿進(jìn)行了壓縮性能測試,結(jié)果顯示80%形變下線性部分的長度達(dá)73.5%,且電阻率在壓縮和回彈時隨形變呈近線性變化;50%形變下,800次循環(huán)后樣品仍可保持初始形貌,應(yīng)力保留率在85%左右。該法合成的石墨烯海綿由于超低的電導(dǎo)率和極好的壓縮性能在彈性導(dǎo)體、壓力傳感器等方面有較好的應(yīng)用前景。
[Abstract]:Graphene has a wide range of applications due to its unique optoelectronic properties, excellent mechanical properties and high specific surface area. However, due to the van der Waals and 蟺-蟺 attraction between graphene layers, graphene tends to be stacked, which greatly inhibits the excellent properties of graphene itself and limits its application in most fields. Because of its unique structure, graphene three-dimensional structure and its nanocomposites can avoid the stacking between graphene layers. At present, the typical synthesis methods of graphene and its composites include vapor deposition, chemical reduction and hydrothermal methods. However, the application of these methods is greatly limited due to the high cost, the use of toxic reductants and harsh high pressure conditions. In this thesis, a mild and clean 緯-ray irradiation method was used to study the preparation of 緯-ray radiation in two graphene (composite) materials. Firstly, at room temperature and atmospheric pressure, the manganese oxide / graphene oxide MNO / rGO) composite material was prepared by 緯 -ray irradiation method, which was used in lithium ion secondary battery negative electrode. 緯 -ray can radiate water to produce hydrated electron reduction potassium permanganate to produce MnO particles of adjustable size. And distributed uniformly on the surface of graphene. The above advantages make the MnO/rGO composites prepared by 緯 -ray irradiation have better electrochemical performance. The specific capacity of MNO / R go composites can still reach 1687 Ma / g ~ (-1) after 500 cycles at current density of 2.2A g ~ (-1). Under the high current density of 0.2 Ag-1, the specific capacity of the MNO / RGO composite can be up to 2175 mAh g ~ (-1). Even at the high current density of 15 Ag-1, the specific capacity of the composite is still up to 546mAh g-1, which is about 1.5 times of the commercial graphite anode. Therefore, 緯-ray irradiation reduction will be a promising method in the preparation of battery materials. Secondly, graphene sponge structure was synthesized by simple 緯-ray radiation under the condition of no surfactant. The influence of acetic acid and ammonia water on the formation of three-dimensional graphene sponge was analyzed by adding acetic acid and ammonia into the dispersion solution of graphene oxide to adjust the dispersion state of go in solvent. The compression properties of graphene sponges were also enhanced by loading 1. 1 脳 10 ~ 4 cm cm-2 CNT(5 wt. on graphene. We also control the concentration of go to adjust the density of graphene sponge to meet different needs. The density of graphene sponge is as low as 5.0 mg / cm ~ (-3), the porosity is as high as 99.8 and the conductivity is only 0.012 S / cm ~ (-1). The compressive properties of sponge were tested. The results showed that the length of linear part in 80% deformation was 73.5%, and the resistivity changed nearly linearly with deformation (50%). After 800 cycles, the initial morphology of the sample could be maintained. The stress retention rate is about 85%. The graphene sponge synthesized by this method has a good application prospect in elastic conductors, pressure sensors and so on due to its ultra-low conductivity and excellent compression properties.
【學(xué)位授予單位】：中國科學(xué)技術(shù)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TQ127.11;TB33

【參考文獻(xiàn)】

相關(guān)期刊論文 前2條

1 Yanfeng Ma;Yongsheng Chen;;Three-dimensional graphene networks: synthesis,properties and applications[J];National Science Review;2015年01期

2 盛凱旋;徐宇曦;李春;石高全;;化學(xué)還原氧化石墨烯制備高性能石墨烯自組裝水凝膠(英文)[J];新型炭材料;2011年01期

，

本文編號：1817527