本文關(guān)鍵詞： 微生物燃料電池 光輔助陽極 輸出電流 界面電子傳遞 不銹鋼材料　出處：《浙江工商大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：能源短缺和環(huán)境污染是當(dāng)今中國面臨的兩大難題。微生物燃料電池(Microbial fuel cells,MFCs)利用具有跨膜電子傳遞能力的電活性微生物,將氧化有機(jī)質(zhì)所產(chǎn)生的電子進(jìn)行定向傳輸,從而實(shí)現(xiàn)化學(xué)能與電能的轉(zhuǎn)化,是一項(xiàng)有望協(xié)同解決能源短缺與環(huán)保污染問題的新興廢水處理技術(shù)。但目前輸出功率低下與工程材料欠缺嚴(yán)重限制了MFCs的進(jìn)一步發(fā)展。基于此,本文利用電極表面修飾光催化材料所形成的光致空穴界面,提高生物膜/陽極界面電勢(shì)差,加速界面電子傳遞速率及微生物呼吸代謝速率,從而獲得更大的輸出功率;同時(shí)選用易工程放大的不銹鋼氈為陽極基底材料,考察光致空穴提升其輸出性能機(jī)制和工程放大的可行性。論文的主要內(nèi)容和結(jié)果如下:1、利用電沉積法成功將α-Fe_2O_3修飾到石墨陽極外側(cè),修飾后的陽極光電流為0.74 A m-2(-0.2 V偏壓)。首次以該電極構(gòu)建光電微生物燃料電池(PMFC),其啟動(dòng)時(shí)間比常規(guī)MFC縮短一半,最大輸出電流提升2倍以上(8.4Am-2)。在開閉光條件切換下,輸出電流響應(yīng)迅速,表明光致空穴界面即時(shí)加速了生物膜/陽極界面電子傳遞速率。此外,PMFC生物陽極的生物膜生長(zhǎng)速率和主要產(chǎn)電微生物Geobacter的豐度(87%)也均顯著高于普通MFC,表明光致空穴界面對(duì)陽極生物膜形成具有長(zhǎng)期促進(jìn)作用,且能定向篩選并富集電活性微生物。2、考察了不同光催化材料、電極基底及生物側(cè)修飾物對(duì)于光致空穴界面效果的影響。結(jié)果表明不同光催化材料(CdS、TiO_2和α-Fe_2O_3)修飾PMFCs所獲電流的提升倍數(shù)之間具有顯著差異,PMFCα-Fe_2O_3和PMFC TiO_2的最大輸出電流分別提升2.0和1.7倍,而PMFCdS提升倍數(shù)最大可達(dá)2.8倍,但隨著CdS光催化材料的失效其輸出電流會(huì)回落至MFC同等水平。光致空穴界面同樣可以加速不銹鋼基底陽極表面的生物膜形成速率,并提升輸出功率,最大電流提升倍數(shù)達(dá)6倍以上。生物界面修飾碳顆粒和聚苯胺可顯著影響MFCs輸出性能,其最大輸出電流分別為9.2和4.6 A m-2,但光致空穴界面仍提升輸出電流2.0倍。綜上推測(cè)光催化材料和電極基底材料是影響光致空穴界面效果的主控因子。3、首次在工程材料不銹鋼電極上分別構(gòu)建了碳微粒薄膜、聚苯胺、中性紅、親水性基團(tuán)和鐵氧化物五種改性層,并探究了其對(duì)于MFCs輸出性能的影響。結(jié)果表明碳微粒薄膜和聚苯胺修飾的陽極具有優(yōu)異的比表面積和生物兼容性,從而分別提升MFCs(3 A m-2)輸出電流至13 A m-2和9 A m-2。中性紅基團(tuán)修飾通過加速生物膜與電極間的電子傳遞,提高輸出電流至4.5 Am-2。親水性基團(tuán)修飾則通過提升微生物在電極表面的成膜速率,提高輸出電流至6 A m-2。基于此,本研究以α-Fe_2O_3作為光催化層、三維不銹鋼氈作為基底、碳微粒負(fù)載作為生物層修飾技術(shù)首次設(shè)計(jì)了一種高性能的復(fù)合三維不銹鋼氈光輔助陽極,最大面積電流密度在光激發(fā)下從26 A m-2提升至46 Am-2,體積電流密度達(dá)20.9 kAm-3,性能在已有報(bào)道的文獻(xiàn)中位列前列。4、將光致空穴界面機(jī)理拓展應(yīng)用至微生物燃料脫鹽池(PMDC)。PMDC最大輸出電流為8 A m-2,隨脫鹽室鹽度的降低(內(nèi)阻增大)而迅速下降,當(dāng)電流低于0.5 Am-2以后脫鹽率達(dá)96%以上,而相同運(yùn)行時(shí)間下MDC脫鹽率低于50%。綜上表明,光輔助修飾是一種使用壽命長(zhǎng)久、作用效果顯著、操作簡(jiǎn)潔環(huán)保的生物陽極改性技術(shù),在廢水處理、產(chǎn)電、合成、產(chǎn)氫等各種生物電化學(xué)領(lǐng)域具有廣闊的應(yīng)用前景。
[Abstract]:Energy shortage and environmental pollution are two major problems in current Chinese face. Microbial fuel cell (Microbial fuel, cells, MFCs) using the electrical activity of microorganisms with transmembrane electron transfer ability, electron generated oxidized organic matter of directional transmission, so as to realize the transformation of chemical energy and electrical energy, is an emerging collaboration is expected to the wastewater treatment technology to solve the energy shortage and environmental pollution problems. But the output power is low and the lack of engineering materials has seriously restricted the further development of MFCs. Based on this, this paper induced interfacial holes formed by surface modification of photocatalytic material of light, improve the biological membrane / anode interface potential at the interface, accelerate the electron transfer rate and microbial respiration the metabolic rate, so as to get higher output power; at the same time using easy scale-up of stainless steel felt as anode substrate materials, light induced hole to enhance its investigation The feasibility and mechanism of the output performance of the amplification of the project. The main contents and results are as follows: 1, using electrodeposition alpha -Fe_2O_3 modified graphite anode side, the anodic photocurrent modified 0.74 A m-2 (-0.2 V bias). For the first time to construct the electrode photoelectric microbial fuel cell (PMFC), the start half the time shorter than the conventional MFC, the maximum output current increase more than 2 times (8.4Am-2). In the opening and closing switch under light conditions, the output current rapid response, show the light induced hole interface instant accelerated biofilm / anode interface electron transfer rate. In addition, the abundance of PMFC Bio anode biofilm growth rate and the main power generation microbial Geobacter (87%) were significantly higher than that of conventional MFC, show the light induced interfacial holes with long-term effect on the anode biofilm formation, and directional screening and enrichment of electroactive microbial.2, tested different photocatalytic 鏉愭枡,鐢墊瀬鍩哄簳鍙?qiáng)鐢熺墿渚т慨楗扮墿瀵逛簬鍏夎嚧绌航I寸晫闈㈡晥鏋滅殑褰卞搷.緇撴灉琛ㄦ槑涓嶅悓鍏夊偓鍖栨潗鏂，

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