【摘要】：以改進(jìn)的Hummers法制備氧化石墨,超聲分散制備了氧化石墨烯(GO)水相分散液并物理涂覆于濕敏襯底制備GO濕敏元件,對其進(jìn)行了FTIR表征,考察了膜厚度對其濕敏性能的影響,研究了元件的濕滯特性、響應(yīng)-恢復(fù)特性、感濕機(jī)理及不同還原程度氧化石墨烯感濕性能。GO在中高濕范圍內(nèi)有一定的感濕特性,但存在濕滯大,低濕范圍內(nèi)不呈線性的問題;不同程度還原GO元件的濕滯和感濕特性曲線的線性度得到一定程度的改善,但元件的靈敏度仍需改善和提高。為提高GO感濕性能,改善線性度,采用涂覆法及共混法制備氧化石墨烯/釩鈦酸復(fù)合材料,考察了涂覆順序、膜厚度、濃度對復(fù)合薄膜濕敏性能的影響,對其感濕機(jī)理進(jìn)行研究。結(jié)果表明:GO-VTi混合膜的濕滯比GO濕敏膜降低3.84%RH,元件響應(yīng)時間為5s,恢復(fù)時間為8s,曲線線性度良好。VTi濕敏材料的加入對GO低濕環(huán)境中感濕特性曲線線性度有了很好的改善,但復(fù)合膜靈敏度有待進(jìn)一步提高。為了提高GO復(fù)合材料的靈敏度,分別采用化學(xué)法和原位聚合法制備氧化石墨烯/聚苯胺復(fù)合材料,對聚苯胺纖維進(jìn)行了SEM表征并對復(fù)合膜進(jìn)行了感濕性能測試,結(jié)果表明RGO/PANI濕敏膜在全濕范圍內(nèi)線性度較好,量程合適,電阻隨濕度變化達(dá)到3個數(shù)量級,濕滯回差約為3.81%RH,響應(yīng)時間約為8s,恢復(fù)時間約為10s,與上述的單一濕敏膜及復(fù)合材料濕敏膜相比,濕敏性能有明顯的改善和提高,且制備工藝簡單、綠色環(huán)保、重復(fù)性好。本文通過原位聚合制備了石墨烯修飾電極,通過FTIR和交流復(fù)阻抗對其進(jìn)行了表征,并測試了其對不同濃度的抗壞血酸的電催化性能及動力學(xué)參數(shù),結(jié)果表明氧化峰電流隨抗壞血酸濃度增大而增大,兩者成線性關(guān)系,最低檢出限為6×10-6mol/L;抗壞血酸的電化學(xué)氧化是單電子轉(zhuǎn)移的反應(yīng),抗壞血酸電催化氧化反應(yīng)的速率常數(shù)k0=3.78×10-6cm2/s,擴(kuò)散系數(shù)D=3.24×10-6 cm2/s。實(shí)驗(yàn)結(jié)果表明了RGO作為電化學(xué)傳感器修飾電極材料的可行性,為拓寬其在電化學(xué)傳感器領(lǐng)域的應(yīng)用提供了理論依據(jù)。
[Abstract]:Graphite oxide was prepared by improved Hummers method. The aqueous dispersion of graphene oxide (GO) was prepared by ultrasonic dispersion. The GO humidity sensor was prepared by physical coating on humidity sensitive substrate. The effect of film thickness on its humidity sensitivity was investigated. The humidity hysteretic property, response-recovery characteristic, humidity sensing mechanism and humidity sensing property of graphene oxide with different reduction degree. Go have certain humidity sensitivity in medium and high humidity range, but there is the problem of large humidity lag and no linearity in low humidity range. The linearity of hysteretic and hygroscopic curves of GO elements is improved to a certain extent, but the sensitivity of the components still needs to be improved and improved. In order to improve the humidity sensitivity and linearity of GO, graphene oxide / vanadium titanate composites were prepared by coating and blending methods. The effects of coating sequence, film thickness and concentration on the humidity sensitivity of composite films were investigated. The mechanism of humidity sensitivity was studied. The results show that the humidity lag of the mixed film is 3.84 RH lower than that of the GO humidity sensitive film, the response time of the element is 5 s, the recovery time is 8 s, and the linearity of the curve is good. The addition of VTi humidity sensing material can improve the linearity of the humidity sensing curve in the low humidity environment of GO. However, the sensitivity of the composite membrane needs to be further improved. In order to improve the sensitivity of GO composites, graphene oxide / Polyaniline composites were prepared by chemical method and in situ polymerization respectively. Polyaniline fibers were characterized by SEM and the moisture sensitivity of the composite films was tested. The results show that the RGO/PANI humidity sensitive film has a good linearity and a suitable measuring range in the whole wet range, and the resistance varies by 3 orders of magnitude with the humidity. The hysteretic hysteresis coefficient is about 3.81 RH, the response time is about 8 s, and the recovery time is about 10 s. Compared with the single humidity sensitive film and the composite humidity sensitive film, the humidity sensitive property is obviously improved and improved, and the preparation process is simple, green and environmental friendly, and the repeatability is good. Graphene modified electrode was prepared by in-situ polymerization and characterized by FTIR and AC complex impedance. The electrocatalytic properties and kinetic parameters of graphene modified electrode for ascorbic acid with different concentrations were tested. The results show that the oxidation peak current increases with the increase of ascorbic acid concentration, and the lowest detection limit is 6 脳 10 ~ (-6) mol / L, and the electrochemical oxidation of ascorbic acid is a single electron transfer reaction. The rate constant of ascorbic acid electrocatalytic oxidation is 3.78 脳 10 ~ (-6) cm ~ (-2) / s, and the diffusion coefficient is 3.24 脳 10 ~ (-6) cm2/s.. The experimental results show the feasibility of RGO as a modified electrode material for electrochemical sensors, which provides a theoretical basis for broadening its application in the field of electrochemical sensors.
【學(xué)位授予單位】：東北石油大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TB332;TP212

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 陳浩;彭同江;孫紅娟;;氧化石墨烯薄膜厚度對元件濕敏性能的影響[J];材料導(dǎo)報;2016年23期

2 魏福祥;許嬪;何禮;張尚正;;抗壞血酸在石墨烯/聚苯胺復(fù)合膜修飾電極上的電化學(xué)行為[J];分析科學(xué)學(xué)報;2014年03期

3 陳軍剛;彭同江;孫紅娟;劉波;趙二正;;還原溫度對氧化石墨官能團(tuán)、結(jié)構(gòu)及濕敏性能的影響[J];無機(jī)化學(xué)學(xué)報;2014年04期

4 任小孟;王源升;何特;;Hummers法合成石墨烯的關(guān)鍵工藝及反應(yīng)機(jī)理[J];材料工程;2013年01期

5 范艷煌;鄒正光;龍飛;吳一;高潔;孔令奇;;以氧化石墨烯為氧化介質(zhì)制備石墨烯/聚苯胺導(dǎo)電復(fù)合材料[J];復(fù)合材料學(xué)報;2013年01期

6 萬臣;彭同江;孫紅娟;黃橋;;不同氧化程度氧化石墨烯的制備及濕敏性能研究[J];無機(jī)化學(xué)學(xué)報;2012年05期

7 王朝霞;陳美鳳;馬心英;;石墨烯修飾玻碳電極用于循環(huán)伏安法測定抗壞血酸[J];理化檢驗(yàn)(化學(xué)分冊);2012年03期

8 董照月;郎穎;姜威;侯洪濤;;單根ZnO納米線半導(dǎo)體器件的制備及濕敏特性研究[J];哈爾濱師范大學(xué)自然科學(xué)學(xué)報;2010年03期

9 馬利;陳超;甘孟瑜;盧葦;陳奉強(qiáng);;磁場(0.8T)環(huán)境中聚苯胺宏觀摻雜動力學(xué)行為探討[J];功能材料;2008年04期

10 劉曉磊;何建平;黨王娟;計亞軍;趙桂網(wǎng);張傳香;;介孔SnO_2的結(jié)構(gòu)表征及其濕敏性能[J];物理化學(xué)學(xué)報;2008年03期

相關(guān)博士學(xué)位論文 前1條

1 李莉;復(fù)合釩酸基材料的制備、表征及其應(yīng)用研究[D];東北石油大學(xué);2011年

，

本文編號：2221562