本文關鍵詞： 柔性石墨紙 錳氧化物 鎳鐵雙氫氧化物 電催化劑 OER反應 電沉積法 水熱法　出處：《廣西大學》2017年碩士論文　論文類型：學位論文

【摘要】：石墨紙是一種由石墨粉末壓制而成的柔韌性良好的薄片材料,具有價格低廉、來源豐富、環(huán)境友好、耐高溫高壓等優(yōu)點,主要應用于制造高溫密封元件、微型器件的導熱元件,同時它也是一種導電導熱能力強且化學穩(wěn)定性良好的柔性基底。本論文以石墨紙作為電極基底,采用電沉積法和水熱法生長活性物質(zhì),通過探討一系列合成條件對其性能的影響,制備出高性能的電催化劑。本論文的研究內(nèi)容總結(jié)如下:首先,以乙酸錳和乙酸銨為原料,以石墨紙為活性基底,通過電沉積法生長錳氧化物沉積層。探討了工藝條件如電流密度、溫度、電鍍液濃度等因素對電極OER催化性能的影響,獲得了最優(yōu)化的沉積條件。利用SEM、XRD和OER性能測試等手段對催化劑的形貌、結(jié)構和性能進行了研究。實驗結(jié)果表明,在沉積電流密度為3 mA·cm-2,沉積溫度70 ℃,采用0.02 mol·L-1 Mn(Ac)2 + 0.01 mol·L-1 NH4Ac溶液,制備出由納米片堆積而成三維網(wǎng)絡多孔結(jié)構,鑒于該結(jié)構具有良好的離子傳輸通道,以及較大的比表面積,電極呈現(xiàn)出了高的OER催化活性。進一步研究表明,350℃qF燒不會改變電極的納米結(jié)構,還能提高其電催化性能。所得的煅燒電極在中性電解液溶液中也表現(xiàn)出優(yōu)異的OER活性。其次,以Ni(N03)2和Fe(N03)3為電鍍液,以石墨紙為基底,通過電沉積法生長無定型NiFe(OH)x沉積層。探討了三種沉積模式包括恒電壓、循環(huán)伏安和脈沖沉積法對電極OER催化性能的影響。對各種沉積模式下的最優(yōu)化沉積條件進行了比較,利用SEM、XPS和OER性能等測試手段,探討了沉積條件對產(chǎn)物形貌、價態(tài)及性能的影響。實驗結(jié)果表明,采用脈沖沉積模式,Ni:Fe = 9:1,溫度為50 ℃下制備出由納米顆粒堆積形成的多孔結(jié)構性能最優(yōu)。最后,以KMnO4為氧化劑,石墨紙為還原劑和基底,通過水熱法進行氧化還原反應,獲得MnO2沉積層。探討了水熱溫度和反應時間對電極形貌的影響。利用SEM、XPS和OER性能測試手段對電極的形貌、價態(tài)和性能進行了研究。實驗結(jié)果表明,在水熱溫度為140 ℃,反應時間為6h時得到的由納米線和納米顆粒相互包裹的網(wǎng)狀結(jié)構,該結(jié)構擁有通暢的離子傳輸通道、較大的活性面積以及較強的MnO2附著力,使得電極呈現(xiàn)出高的OER活性。將MnO2沉積層溶解后獲得新型的石墨紙基底,SEM表征結(jié)果顯示,石墨紙表面形成密集的孔道結(jié)構,提供更多的活性位點,使得該基底比原始石墨紙具有更高的活性。
[Abstract]:Graphite paper is a kind of flexible sheet material made from graphite powder. It has the advantages of low price, rich source, friendly environment, high temperature and high pressure, etc. It is mainly used in manufacturing high temperature sealing element and heat conduction element of micro device. It is also a flexible substrate with strong thermal conductivity and good chemical stability. In this paper, graphite paper is used as electrode substrate and active substances are grown by electrodeposition and hydrothermal method. High performance electrocatalysts were prepared by studying the effects of a series of synthetic conditions on their properties. The main contents of this paper are summarized as follows: firstly, manganese acetate and ammonium acetate were used as raw materials and graphite paper as active substrate. Manganese oxide deposits were grown by electrodeposition. The effects of process conditions such as current density, temperature and concentration of electroplating solution on the catalytic performance of electrode OER were discussed. The optimum deposition conditions were obtained. The morphology, structure and properties of the catalyst were studied by means of OER and SEM. The results showed that the deposition temperature was 70 鈩，

本文編號：1540906