發(fā)布時(shí)間：2018-01-25 05:56

  本文關(guān)鍵詞： 循環(huán)伏安 復(fù)合電極 二氧化錳 導(dǎo)電聚合物 比電容 氧氣還原反應(yīng)　出處：《河北師范大學(xué)》2010年碩士論文　論文類型：學(xué)位論文

【摘要】： 作為一種重要的電極材料,MnO2由于具有價(jià)格低廉、比表面積大、來源廣泛、對(duì)環(huán)境友好、電化學(xué)性能穩(wěn)定、理論比電容高和可逆性高等優(yōu)點(diǎn),已廣泛應(yīng)用于中性鋅錳干電池作去極化劑及一次、二次堿錳和鋰錳電池中。但是由于天然二氧化錳(natural manganese dioxide, NMD)礦的電化學(xué)活性較差,而且近幾年來二氧化錳礦產(chǎn)巨大的開采量導(dǎo)致其資源日益枯竭,化學(xué)電源工作者就更加注重對(duì)二氧化錳電極材料進(jìn)行改性的研究。 本文在利用循環(huán)伏安(cyclic voltammetry, CV)的電化學(xué)方法沉積二氧化錳的基礎(chǔ)上,以掃描速度為例探討了沉積條件對(duì)二氧化錳比電容的影響。并比較了不同方法電鍍二氧化錳形貌的差異。通過分別與電子導(dǎo)電聚合物(electronically conducting polymers, ECPs):聚苯胺(polyaniline, PANI)和聚吡咯(polypyrrole, PPy)組成復(fù)合二氧化錳電極研究了二氧化錳的摻雜性,獲得的主要結(jié)果、結(jié)論如下: 1、可以利用循環(huán)伏安的方法在石墨電極上電沉積二氧化錳,根據(jù)Mn(Ⅱ)的擴(kuò)散系數(shù)計(jì)算了反應(yīng)的摩爾電子轉(zhuǎn)移數(shù),并根據(jù)不同掃描速度電沉積二氧化錳的電化學(xué)反應(yīng)數(shù)據(jù)推測了石墨電極上循環(huán)伏安法沉積MnO2的EC反應(yīng)(electrochemical-chemical reaction)機(jī)理。電化學(xué)測試表明制備二氧化錳的面積比電容隨著掃描速度的增大而減小,而且電極材料具有較強(qiáng)的對(duì)氧還原反應(yīng)的催化活性,并首次通過速控步和平衡態(tài)近似法建立該反應(yīng)的催化動(dòng)力學(xué)模型。 2、通過利用包括計(jì)時(shí)電位、電位階躍和恒電位在內(nèi)的其它電化學(xué)實(shí)驗(yàn)方法得到形貌可控的二氧化錳。 3、可以利用循環(huán)伏安的方式在石墨電極上電沉積二氧化錳-聚苯胺復(fù)合電極材料,二氧化錳-聚苯胺的掃描電鏡(scanning electron microscopy, SEM)照片表明二氧化錳包裹著聚苯胺形成空間鏈結(jié)構(gòu)。X-射線能量色散譜(energy dispersive x-ray spectrometer, EDS)元素分析圖中Mn的峰說明在石墨電極上的錳元素來自于電沉積出來的二氧化錳。熱重分析(thermo gravimetric analysis, TGA)表明二氧化錳-聚苯胺復(fù)合電極材料具有良好的熱穩(wěn)定性。 4、可以利用循環(huán)伏安的技術(shù)在石墨電極上沉積制備二氧化錳-聚吡咯復(fù)合膜電極,循環(huán)伏安測試表明二氧化錳-聚吡咯電極具有較強(qiáng)的儲(chǔ)存電荷能力,恒電流充放電曲線表明二氧化錳-聚吡咯材料具有良好的循環(huán)穩(wěn)定性。氧還原電測試顯示二氧化錳-聚吡咯電極具有對(duì)氧氣還原較高的催化性。
[Abstract]:As an important electrode material, MNO _ 2 has the advantages of low price, large specific surface area, wide source, friendly to the environment, stable electrochemical performance, high theoretical capacitance and high reversibility. It has been widely used as depolarizer and primary, secondary alkaline manganese and lithium manganese battery for neutral zinc manganese dry battery. But natural manganese dioxide is natural due to natural manganese dioxide. The electrochemical activity of NMD) ore is poor, and in recent years, the huge exploitation of manganese dioxide mineral resources has resulted in the depletion of its resources. Chemical power supply workers pay more attention to the modification of manganese dioxide electrode materials. In this paper, manganese dioxide was deposited by cyclic voltammetry (CVV) electrochemical method. The effect of deposition conditions on the specific capacitance of manganese dioxide was investigated by taking the scanning rate as an example. The morphologies of manganese dioxide electroplated by different methods were compared. Electronically conducting polymers. Polyaniline Polyaniline (PANI) and polypyrrole (polypyrrole). PPy-based composite manganese dioxide electrode was used to study the doping of manganese dioxide. The main results obtained are as follows: 1. Manganese dioxide can be electrodeposited on graphite electrode by cyclic voltammetry. The molar electron transfer number of the reaction can be calculated according to the diffusion coefficient of mn (鈪，

本文編號(hào)：1462179