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  本文選題：光電陽極 + 光電化學分解水�。� 參考：《北京化工大學》2015年碩士論文

【摘要】：近幾十年,能源危機成為全球關(guān)注的問題,開發(fā)利用新能源已經(jīng)成為國內(nèi)外研究的熱點,光電化學(PEC)分解水制氫為人類獲取新能源提供了一種有效的方法。傳統(tǒng)的光電陽極材料主要是以Ti02,ZnO, WO3等為代表的半導體氧化物材料,但這些傳統(tǒng)光電陽極材料存在著可見光利用率低、光生電子-空穴易復合和量子效率低等問題,限制了它們的近一步應(yīng)用。本文在傳統(tǒng)的光電陽極材料ZnO, WO3基礎(chǔ)上,通過構(gòu)筑ZnO納米陣列多級結(jié)構(gòu)、沉積貴金屬金納米顆粒和引入水滑石(LDH)助催化劑等方法,在提高活性位,抑制電子-空穴復合,擴大光譜吸收以及提高水氧化動力學等方面實現(xiàn)了對光電陽極材料的優(yōu)化,提高了光電化學分解水的性能。同時,通過DFT理論計算的方法對光電陽極材料在光電化學分解水的過程中一些機理進行了探索。具體研究內(nèi)容如下：1、通過水熱法合成了ZnO NR@NP核殼陣列,研究表明ZnONR@NP核殼陣列多級結(jié)構(gòu)有利于ZnO活性位點的暴露,提高了光電化學分解水的效率。進一步用Au納米顆粒進行修飾后,Au-ZnO NR@NP陣列光電流有很大提高,在電壓0.6 V vs. Hg/Hg2Cl2下光電流密度為1.47 mA·cm-2,而ZnO NR@NP陣列為1.17 mA·cm-2。 Au-ZnONR@NP光電化學分解水性能的增強是由于金納米顆粒形成電子陷阱抑制了ZnO光生電子-空穴對的復合,同時,金納米顆粒的SPR效應(yīng)提高了可見光的利用率。密度泛函理論(DFT)計算進一步證明ZnO的光激發(fā)電子容易轉(zhuǎn)移到Au納米顆粒上。該工作提供了一個有效的制備貴金屬／半導體多級結(jié)構(gòu)納米陣列的方法。2.通過電合成的方法實現(xiàn)了NiFe-LDH納米片在W03納米線陣列上的有序生長,并探究了在光電化學分解水方面NiFe-LDH與W03之間的協(xié)同作用。W03本身具有光催化性能,NiFe-LDH具有優(yōu)良的電催化性能,兩者結(jié)合形成的WO3@NiFe-LDH核殼納米陣列顯著增強了光電化學分解水的性能。NiFe-LDH殼作為助催化劑增加了整個體系的反應(yīng)動力學,同時抑制了W03電子-空穴對的復合。本論文提出了一個制備半導體氧化物和LDH復合多級納米陣列材料的方法,其顯著提高了半導體金屬氧化物的PEC分解水性能。
[Abstract]:In recent decades, the energy crisis has become a global concern, the development and utilization of new energy has become a hot spot at home and abroad. Photoelectrochemical PECs provide an effective method for human to obtain new energy. The traditional photoanode materials are mainly semiconductor oxide materials, such as Ti02ZnO, WO3, etc. However, these traditional photoanode materials have some problems, such as low utilization of visible light, easy recombination of photogenerated electron-hole and low quantum efficiency, etc. Limit their further application. In this paper, based on the traditional photoanode materials, ZnO, WO3, the multistage structure of ZnO nanoarrays, the deposition of noble metal gold nanoparticles and the introduction of hydrotalcite WO3 co-catalysts are used to improve the active sites and inhibit the electron-hole recombination. The properties of photoelectrochemical decomposition of water have been improved by optimizing the photoanode materials in the aspects of expanding the absorption spectrum and improving the kinetics of water oxidation. At the same time, the mechanism of photoelectrochemical decomposition of water was investigated by DFT theory. ZnO NR@NP core-shell arrays were synthesized by hydrothermal method. The results show that the multilevel structure of ZnONR@NP core-shell arrays is beneficial to the exposure of ZnO active sites and improves the efficiency of photochemical decomposition of water. After further modification with au nanoparticles, the photocurrent of Au-ZnO NR@NP arrays was greatly improved, with a photocurrent density of 1.47 Ma cm-2 at a voltage of 0.6 V vs. Hg/Hg2Cl2 and a 1.17 Ma cm-2 of ZnO NR@NP arrays. The enhancement of the photochemical decomposition of water by Au-ZnONR@NP is due to the formation of electron traps in gold nanoparticles which inhibit the photogenerated electron-hole pairs of ZnO. At the same time, the SPR effect of gold nanoparticles increases the utilization rate of visible light. The density functional theory (DFT) calculation further proves that the photoexcited electrons of ZnO are easily transferred to au nanoparticles. This work provides an effective method for preparing noble metal / semiconductor multilevel nanoarrays. The ordered growth of NiFe-LDH nanowires on W03 nanowire arrays was realized by electrosynthesis. The synergism between NiFe-LDH and W03 in photochemical decomposition of water was investigated. The WO3@NiFe-LDH core-shell nanoarrays formed by the combination can significantly enhance the photochemical decomposition of water. NiFe-LDH shell as a co-catalyst increases the reaction kinetics of the whole system and inhibits the recombination of the W03 electron-hole pair. In this paper, a method of preparing semiconductor oxide and LDH composite multistage nanoarrays is proposed, which improves the PEC decomposition water performance of semiconductor metal oxides.
【學位授予單位】：北京化工大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：O646.54;TQ116.2

【共引文獻】

相關(guān)期刊論文 前1條

1 Zhong Liu;Baoliang Lv;Dong Wu;Yuhan Sun;Yao Xu;;Magnetic and electrochemical behavior of rhombohedral α-Fe_2O_3 nanoparticles with (104) dominant facets[J];Particuology;2013年03期

相關(guān)博士學位論文 前2條

1 李強;鐵基納米材料的制備及其與蛋白質(zhì)的相互作用性質(zhì)研究[D];華中師范大學;2014年

2 程位任;低維鐵氧化物功能材料結(jié)構(gòu)與性能調(diào)控研究[D];中國科學技術(shù)大學;2015年

相關(guān)碩士學位論文 前3條

1 鄧久軍;納米α相三氧化二鐵光解水制氫研究[D];蘇州大學;2013年

2 艾青;鐵薄膜等離子體氧化及性能研究[D];東北大學;2012年

3 孟禮榮;TiO_2基納米復合材料的合成及其對農(nóng)藥廢水的處理與光電檢測[D];安徽理工大學;2015年

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本文編號：1863353