本文選題：水氧化　切入點：電解水　出處：《大連理工大學》2015年博士論文

【摘要】：水氧化反應能夠為太陽能分解水制氫提供質子和電子,但水氧化涉及4個電子和4個質子的轉移且需要很高的活化能,是實現(xiàn)人工光合作用的瓶頸。因此,發(fā)展廉價高效的水氧化催化劑及負載有催化劑的陽極和光陽極是實現(xiàn)太陽能轉換和儲存的關鍵。 本文通過π-π堆積作用成功的將帶芘吸附基團的高效水氧化催化劑Rul負載到導電性很好的MWCNTs電極上。得到Rul/MWCNTs/ITO陽極的氧化水過電位僅為280mV,在1.4Vvs NHE的電位下得到220pA/cm2穩(wěn)定的催化電流密度。電解10h后的產氧TON為11000,TOF為0.39s-1。與羧酸官能團修飾的陽極相比,通過π-π堆積作用修飾的陽極不僅制備簡便,而且對工作時電解液的pH值等條件沒有特殊要求,為分子催化劑在陽極上的修飾開辟了一條新的途徑。 為進一步開發(fā)具有實際意義的光、電器件,本文選取廉價的立方烷Co水氧化分子催化劑,通過將Col催化劑嵌入Nafion聚合物覆蓋的FTO導電玻璃和具有可見光吸收特性的α-Fe2O3半導體薄膜,制備了FTO/Nafion/Col復合陽極和FTO/Nafion/a-Fe2O3/Col光陽極。在電催化中,FTO/Nafion/Col復合陽極在中性磷酸緩沖溶液中1.4V下的催化電流密度為230μA/cm2,持續(xù)工作10h未見明顯活性降低。在光催化中,在0.6V偏壓和光照下,FTO/Nafion/α-Fe2O3/Col光陽極的催化光電流密度維持在350μA/cm2。這是首個不含貴金屬的分子催化劑/無機半導體光陽極。 本文還開發(fā)了基于鈷氧化物的陽極。通過電沉積的方法簡單而快速地得到了兩個沉積在FTO電極表面具有電催化水氧化活性的非定型鈷氧化物膜Co-W和Co-Mo。在Na2WO4和Na2MoO4溶液中,FTO/Co-W和FTO/Co-Mo陽極在1.4V電位下催化電流密度達到1.45mA/cm2和0.95mA/cm2。與己報道的Co-Pi催化劑相比,Co-W能在不含Co2+的電解液中穩(wěn)定工作13h沒有明顯活性降低,這在實際應用方面具有重要意義。 另外,本文以探索新型高效Fe水氧化分子催化劑為目的,對三齒、四齒、五齒配位；環(huán)狀配體配位等不同類型配位環(huán)境的11個Fe配合物和9個原位生成的Fe配合物催化水氧化的活性進行研究。得到Fe3和Fe6兩個新型水氧化Fe分子催化劑,其中Fe6的TON達到65,且具有優(yōu)異的穩(wěn)定性,為Fe分子催化劑修飾水氧化陽極奠定了基礎。 本文開發(fā)了高效廉價的水氧化分子催化劑,采用不同方法制備了多個水氧化催化劑修飾的陽極和首個非貴金屬分子催化劑修飾的半導體光陽極,對構建高效光解水制氫體系有重要價值。
[Abstract]:Water oxidation can provide protons and electrons for solar energy to decompose water to produce hydrogen. However, water oxidation involves the transfer of 4 electrons and 4 protons and requires high activation energy, which is the bottleneck of artificial photosynthesis. The development of cheap and efficient water oxidation catalyst and supported anode and photoanode is the key to realize solar energy conversion and storage. In this paper, the highly efficient water oxidation catalyst (Rul) with pyrene adsorption group was successfully loaded on the MWCNTs electrode with good electrical conductivity by 蟺-蟺 piling. The oxidation water overpotential of Rul/MWCNTs/ITO anode was only 280 MV, and 220pA/cm2 was stable at the potential of 1.4Vvs NHE. After electrolysis for 10 h, the TON of oxygen production was 11000kT / F 0.39s-1.Compared with the anodes modified by carboxylic acid functional groups, the catalytic current density was determined. The anode modified by 蟺-蟺 stacking is not only easy to prepare, but also has no special requirement for pH value of electrolyte, which opens a new way for the modification of molecular catalyst on anode. In order to further develop light and electrical components of practical significance, a cheap Cuban-Co water oxidation molecular catalyst was selected in this paper. By embedding Col catalyst into FTO conductive glass covered by Nafion polymer and 偽 -Fe _ 2O _ 3 semiconductor film with visible light absorption property, FTO/Nafion/Col composite anode and FTO/Nafion/a-Fe2O3/Col photoanode were prepared. The catalytic current density of FTO / Nafion / Col composite anode was 230 渭 A / cm ~ 2 at 1.4 V in neutral phosphoric acid buffer solution in electrocatalysis. The photocurrent density of FTO / Nafion / 偽 -Fe _ 2O _ 3 / Col photoanode is maintained at 350 渭 A / cm ~ 2 路cm ~ (2). This is the first molecular catalyst / inorganic semiconductor photoanode without noble metal. The anode based on cobalt oxide was also developed. Two amorphous cobalt oxide films Co-W and Co-Mo-deposited on the surface of FTO electrode with electrocatalytic water oxidation activity were obtained by electrodeposition. In Na2WO4 and Na2MoO4. The catalytic current density of FTO / Co-W and FTO/Co-Mo anode reached 1.45mA/cm2 and 0.95mA / cm ~ 2 at 1.4V potential in solution. Compared with the reported Co-Pi catalyst, the co-W catalyst could work steadily in the electrolyte without Co2 for 13 h without obvious decrease in activity. This is of great significance in practical application. In addition, the aim of this paper is to explore a new high efficient catalyst for Fe water oxidation, and coordinate with three, four and five teeth. The catalytic activity of 11 Fe complexes and 9 in situ Fe complexes in different coordination environments, such as cyclic ligand coordination, for water oxidation was studied. Two novel Fe molecular catalysts, Fe3 and Fe6, were obtained. The TON of Fe6 reaches 65 and has excellent stability, which lays the foundation for Fe molecular catalyst to modify the water oxidation anode. In this paper, high efficient and cheap molecular catalysts for water oxidation have been developed. The anode modified by water oxidation catalyst and the semiconductor photoanode modified by the first non-noble metal molecular catalyst have been prepared by different methods. It is of great value for the construction of efficient photodissociation water hydrogen production system.
【學位授予單位】：大連理工大學
【學位級別】：博士
【學位授予年份】：2015
【分類號】：TQ116.2;O646

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本文編號：1674605