本文關(guān)鍵詞：電沉積法制備過渡金屬氧化物薄膜與電催化性能研究　出處：《西南石油大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 析氧反應(yīng) 過渡金屬氧化物 薄膜 循環(huán)伏安法 催化性能

【摘要】：析氧反應(yīng)(OER)作為光電分解水的半反應(yīng)之一,其自身固有的緩慢的動力學(xué)是限制水分解的總效率的重要影響因素�，F(xiàn)階段,開發(fā)高效的OER催化劑已成為可再生能源技術(shù)的核心,并因此激起廣泛的研究興趣。第一行過渡金屬(Mn、Fe、Co、Ni和Cu)氧化物,氫氧化物(羥基氧化物),包括單金屬或多金屬元素,都對OER反應(yīng)具有一定的催化活性。電沉積法以其簡單、快速、高效的優(yōu)點而常被用于制備OER催化劑。其在含有單金屬/多金屬離子或者金屬絡(luò)合物的前驅(qū)體溶液中,通過陰極/陽極電沉積法將催化劑薄膜沉積至電極表面。它僅需一臺電化學(xué)工作站,便能精確的調(diào)控催化劑的成核和生長過程,純度,結(jié)構(gòu)以及形貌,有利于實現(xiàn)電催化劑的大規(guī)模工業(yè)化生產(chǎn)。因此,詳細(xì)探討利用成本低廉的電沉積法制備高效的過渡金屬氧化物催化劑變得極具意義。本次研究內(nèi)容主要分為下述幾點:1.以銦錫氧化物(ITO)作為基底,在含有Fe3+等混合金屬離子的前驅(qū)體溶液中,利用陽極循環(huán)伏安法(CV)制備得到一系列的Fe基薄膜催化劑(包括二元、三元以及四(五)元金屬氧化物薄膜)。并以沉積二元FeNiOx氧化物薄膜為例,通過探索沉積電位窗口、沉積時間以及前驅(qū)體中金屬離子配比,以最終制備的催化劑性能優(yōu)劣作為衡量標(biāo)準(zhǔn),獲得最優(yōu)沉積條件。并以此作為制備Fe基催化劑的基準(zhǔn),結(jié)果發(fā)現(xiàn),沉積的二元金屬氧化物 CoFeOx、FeNiOx,三元金屬氧化物 NiCoFeOx、CuNiFeOx、CuCoFeOx,以及四元金屬氧化物CuCoNiFeOx在堿性介質(zhì)中具有較高的OER催化活性。除此之外,輔以無鐵的Ni-Co系列催化劑與之進(jìn)行對比,得到NiCoOx的OER性能可與FeNiOx相媲美。通過XRD、SEM、EDS以及XPS分析不同金屬氧化物薄膜的結(jié)構(gòu)、表面形貌、組成以及價態(tài),進(jìn)而詳細(xì)的研究金屬摻雜對OER催化性能的影響。通過比較電荷轉(zhuǎn)移電阻Rct以及活性面積ECSA的大小,從本質(zhì)上比較催化活性的優(yōu)劣。2.在陽極CV沉積法的基礎(chǔ)上,衍生出一種逐步沉積法,分別以ITO和泡沫鎳(NF)作為基底,先經(jīng)陰極恒電位沉積Ni、Co以及NiCo,再更換至含F(xiàn)e3+的NaOAc溶液中,通過陽極CV沉積法制得NiFeOx、CoFeOx以及NiCoFeOx薄膜。通過該法制備的樣品形貌與一步陽極CV沉積的催化劑有所差異。Fe基薄膜催化劑在堿性條件下均展現(xiàn)出優(yōu)異的OER催化活性以及優(yōu)秀的穩(wěn)定性。值得一提的是,以NF作基底時,Fe基金屬氧化物構(gòu)建出獨特的層狀多孔結(jié)構(gòu),使催化劑具有大的工作表面積以及優(yōu)秀的氣泡消散能力,從而在催化過程中暴露出更多的活性位點,OER性能得到進(jìn)一步提升。
[Abstract]:As one of the half reactions of photoelectricity to decompose water, the inherent slow kinetics of oxygen evolution reaction is an important factor to limit the total efficiency of water decomposition. The development of efficient OER catalysts has become the core of renewable energy technology and has aroused extensive research interest. Hydroxide (hydroxyl oxide), including monometallic or polymetallic elements, has a certain catalytic activity for OER reaction. Electrodeposition method is simple and rapid. The advantages of high efficiency are often used in the preparation of OER catalysts in precursor solutions containing monometallic / polymetallic ions or metal complexes. The catalyst film is deposited on the electrode surface by cathodic / anodic electrodeposition. It requires only an electrochemical workstation to accurately control the nucleation and growth process, purity, structure and morphology of the catalyst. It is advantageous to realize the large-scale industrial production of electrocatalyst. It is of great significance to prepare high efficient transition metal oxide catalysts by low cost electrodeposition. The main contents of this study are as follows: 1. ITO is used as the substrate. A series of Fe-based thin film catalysts (including binary) were prepared by anodic cyclic voltammetry in the precursor solution containing Fe3 and other mixed metal ions. Taking binary FeNiOx oxide films as an example, the potential window, the deposition time and the ratio of metal ions in the precursor were explored. The optimum deposition conditions were obtained according to the performance of the final prepared catalysts, and the results showed that the deposited binary metal oxides (CoFeOx) were used as the basis for the preparation of Fe-based catalysts. FeNiOx, a ternary metal oxide NiCoFeOx-CuNiFeOx-CuCoFeOx. In addition, the quaternary metal oxide CuCoNiFeOx has higher catalytic activity for OER in alkaline medium. In addition, a series of iron-free Ni-Co catalysts are used to compare with it. The OER properties of NiCoOx are comparable to those of FeNiOx. The structure and surface morphology of different metal oxide films are analyzed by XRDX SEMDS and XPS. The effect of metal doping on the catalytic performance of OER was studied in detail. The size of the charge transfer resistance (Rct) and the active area (ECSA) were compared. On the basis of anodic CV deposition method, a kind of step by step deposition method was derived, which was based on ITO and foamed nickel (NFN), respectively. NiCo and NiCowere deposited by cathodic potentiostatic deposition, and then replaced into NaOAc solution containing Fe3. NiFeOx was prepared by anodic CV deposition. CoFeOx and NiCoFeOx thin films. The morphology of the samples prepared by this method is different from that of the catalysts deposited by one-step anode CV deposition. Fe-based thin film catalysts exhibit excellent O in alkaline conditions. ER catalytic activity and excellent stability. When NF was used as the substrate, a unique layered porous structure was constructed, which made the catalyst have a large working surface area and excellent bubble dissipating ability. As a result, more active sites were exposed in the catalytic process, and the performance of OER was further improved.
【學(xué)位授予單位】：西南石油大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TB383.2;O643.36
，

本文編號：1381236