【作者】 王俊红；

【导师】 陈野；

【作者基本信息】 哈尔滨工程大学 ， 化学工程与技术， 2023， 硕士

【摘要】 微生物燃料电池（MFC）是把生物能转化成电能的一种产电装置,是现如今新能源和环境领域研究的热门。MFC的产电性能主要受到阳极材料的影响,本论文选择双金属ZIF和石墨烯复合衍生物改性的聚吡咯（PPy）复合导电水凝胶电极作为MFC阳极,以提高MFC的产电性能。在PPy水凝胶的基础上引入MOFs,采用物理掺杂和原位生长相结合的方法,在碳毡上制备了复合水凝胶（包含Fe-NC/PPy,Zn-NC/PPy,Fe,Zn-NC/PPy）。SEM测试显示Fe,Zn-NC材料含有许多的导电纳米微球,在复合水凝胶中与聚吡咯三维网络相连。电化学测试结果表明,Fe,Zn-NC/PPy复合水凝胶具有最优的电化学性能,并且当Fe和Zn的摩尔比例为2:1时电极具有最好的电化学性能。将制备的电极作为MFC阳极时,以Fe,Zn-2:1-NC/PPy为阳极的MFC表现出最优的产电性能,最大功率密度可达到4.933 W/m³,更小的电荷转移电阻（2.21Ω）。为了进一步提高复合水凝胶的EET效率和MFC产电性能,设想通过引入S元素来提高微生物膜活性和阳极表面微生物的定植数量以实现MFC功率密度的提高。分别用硫粉,硫脲和硫代乙酰胺对双金属ZIF进行硫化处理,将其制成S粉/PPy,硫脲/PPy和硫代乙酰胺（TAA/PPy）水凝胶,并用在MFC阳极。TAA硫化制备的Fe,Zn-NS材料呈现多面体结构,而其他硫化方法制备的材料出现不同程度的塌陷或团聚。TAA/PPy阳极MFC的稳定输出电压（603 m V）高于硫脲/PPy阳极（577 m V）,硫化后的生物阳极呈现出更低的电荷转移电阻,实现了微生物膜与电极之间更高的电荷转移动力学。同时,TAA/PPy为阳极的MFC呈现出更大的功率密度（6.546 W/m³）。为了提高复合水凝胶生物电催化位点的活性以及电荷转移效率,设想制备具有插层结构的rGO/Fe,Zn-NS来改善MFC的整体性能。在以往利用rGO将MOFs催化活性位点分散的基础上,将rGO与Fe,Zn-NS进行插层,制备出具有三明治结构rGO/Fe,Zn-NS-X,最后与PPy水凝胶复合制备rGO/Fe,Zn-NS/PPy-X电极。电化学性能测试证实,rGO/Fe,Zn-NS/PPy-3（65 mg GO）电极更大的面积比电容（1296.95 F/m²）、更低的电荷转移电阻（8.198Ω）和更高的电催化活性（I₀=0.643 m A/cm²）。rGO/Fe,Zn-NS/PPy-3作为MFC阳极时,最大功率密度可以达到8.283 W/m³。这是由于裸露在水凝胶表面的石墨烯活性边缘更有利于产电微生物的定植和接触,利于直接胞外电子传递的进行,而均匀分散的Fe-Zn-N和Fe-Zn-S催化活性中心更大程度上促进了活性微生物膜与生物阳极之间的间接胞外电子传递效率。更多还原

【Abstract】 Microbial Fuel Cell（MFC）was a power generation device that can convert biological energy into electrical energy,and was currently a hot research topic in the field of new energy and the environment.Among them,the choice of anodic material was crucial to power generation performance of MFC.In this paper,the polypyrrole（PPy）composite conductive hydrogel electrode modified with bimetal ZIF and graphene composite derivatives was selected as the MFC bioanode to improve the power generation performance of MFC.Introduced MOFs on the basis of PPy hydrogel,and used the method of combining physical doping with in-situ growth to prepare composite hydrogels（including Fe-NC/PPy,Zn-NC/PPy,Fe,Zn-NC/PPy）on the carbon felt.SEM test revealed that Fe,Zn-NC materials contained many conductive nanospheres,which were connected with the three-dimensional network of polypyrrole in the composite hydrogel.The results of electrochemical tests showed that the Fe,Zn-NC/PPy composite hydrogel has the best electrochemical performance,and the electrode had the best electrochemical performance when the molar ratio of Fe and Zn was 2:1.When the prepared electrode is used as the MFC anode,the MFC with Fe,Zn-2:1-NC/PPy as the anode exhibited the optimal electricity generation performance,with a maximum power density of 4.933 W/m³ and a lower charge transfer resistance（2.21Ω）.In order to further improved the EET efficiency of the composite hydrogel and the power generation performance of MFC,it was envisaged to increase the microbial membrane activity and the number of microorganisms colonized on the anode surface through the introduction of S element to achieve the improvement of MFC power density.The bimetallic ZIF was vulcanized with sulfur powder,thiourea and thioacetamide respectively to prepare S powder/PPy,thiourea/PPy and thioacetamide（TAA/PPy）hydrogels,which were used as MFC anode.The Fe,Zn-NS materials prepared by TAA vulcanization exhibited a polyhedral structure,while materials prepared by other vulcanization methods appeared varying degrees of collapse or aggregation.The stable output voltage of TAA/PPy anode MFC（603 m V）was higher than that of thiourea/PPy anode（577 m V）,and the sulfurized bioanode exhibited lower charge transfer resistance,achieving higher charge transfer kinetics between the microbial film and the electrode.Meanwhile,MFC with TAA/PPy anode exhibited a higher power density（6.546W/m³）.In order to improved the activity of composite hydrogel bioelectricity catalytic sites and charge transfer efficiency,it was envisaged to prepare rGO/Fe,Zn NS with intercalated structure to improve the overall performance of MFC.In this chapter,on the basis of using rGO to disperse the active site of MOFs,the sandwich structure of rGO/Fe,Zn-NS-X was prepared by intercalation of rGO with Fe,Zn-NS.Finally,the sandwich structure of rGO/Fe,Zn-NS-X was compounded with PPy hydrogel to prepare rGO/Fe,Zn-NS/PPy-X electrodes.Electrochemical performance tests confirmed that rGO/Fe,Zn-NS/PPy-3（65 mg GO）electrodes had a larger capacitance（1296.95 F/m²）,a lower charge transfer resistance（8.198Ω）,and a higher electrocatalytic activity（I₀=0.643 m A/cm²）.When rGO/Fe,Zn-NS/PPy-3 are used as MFC anodes,the maximum power density can reach 8.283 W/m³.Because the graphene active edge exposed on the hydrogel surface was more conducive to the colonization and contact of electrogenerating microorganisms,and was conducive to the direct extracellular electron transfer,while the evenly dispersed Fe-Zn-N and Fe-Zn-S catalytic active centers promoted the indirect extracellular electron transfer efficiency between the active microbial membrane and the bioanode to a greater extent.更多还原