微生物燃料电池电极材料研究进展

微生物燃料电池以微生物为催化剂将化学能直接转化成电能,可用于废水处理并产生电能,是一种极具应用前景的生物电化学技术. 本文综述了近年来微生物燃料电池电极材料的制备、功能修饰及表面构建等的研究进展,着重介绍了炭基纳米材料的微结构与成分对微生物燃料电池性能的影响,并分析了微生物燃料电池电极材料现存的主要问题,以期不久的将来微生物燃料电池能付之实用.     

在体酶生物燃料电池的研究进展

酶生物燃料电池(Enzymatic biofuel cells,EBFCs)具有高专一性和催化性能,可催化与氧化还原反应有关的燃料并获得电能.可用的生物燃料,如葡萄糖、乳酸和丙酮酸盐,可以从汗液、泪液和血液中提取,因而以体液为燃料的EBFCs在可植入式或可穿戴式设备中具有良好的应用前景.采用生物电催化机理对酶生物燃料电池在体液发电中的应用进行了研究,以及对可植入式或可穿戴式生物燃料电池的主要挑战和未来的前景进行了展望.     

电沉积制备MnO2催化剂及其在微生物燃料电池中的应用

通过电沉积的方法获得了一种具有均匀孔隙结构的海绵状二氧化锰催化剂,结合扫描电子显微镜(SEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)等手段表征了所制备材料的表面形貌、结构及元素构成和赋存价态,采用线性伏安扫描(LSV)法对电沉积材料的电化学性能进行分析,考察其催化氧还原反应的活性,最后以合成的材料为阴极催化剂,构建微生物燃料电池系统,考察其在微生物燃料电池中的应用效果。结果表明,以电沉积二氧化锰为阴极催化剂的微生物燃料电池最大功率密度为975.6 mW/m~2,是以商业二氧化锰为阴极催化剂的电池的1.7倍;这表明作为一种经济、高效、环境友好的阴极氧还原催化剂,电沉积法制备的二氧化锰为实现阴极催化剂的低成本制备以及微生物燃料电池放大化推进提供了新的研究途径。     

生物燃料电池的研究进展

简要介绍生物燃料电池的工作原理、分类,归纳近年来国内外研究现状.讨论了电子传递媒介体在生物燃料电池中的作用以及如何提高电池性能的对策.最后,探讨了影响生物燃料电池研究进展的瓶颈,并展望其应用前景.     

微生物燃料电池

结合最近几年来微生物燃料电池研究进展情况，对微生物燃料电池的电子转移机理，影响电子转移的主要因素和解决方法，以及微生物燃料电池实用化过程中所面临的问题和应用前景进行了综述。     

酶生物燃料电池自供能传感器的研究现状及应用

在现代分析领域中,对于生物传感器的要求不断倾向于微型化和便捷化。基于酶型生物燃料电池的自供能传感器在检测目标物的同时可以提供能量,避免了外电源的使用,为生物传感器的微型化和便捷化发展提供了有效途径,日益成为人们关注的焦点。本文按照设计原理进行分类,对近五年内发展的基于酶型生物燃料电池的自供能传感器进行了综述,并展望了其今后的研究趋势和应用前景。     

化学修饰炭黑在微生物燃料电池中的生物产电行为

研究发现微生物燃料电池从启动到稳定运行的过程中往往存在一种现象,就是在高电流密度下,微生物燃料电池的输出电压会出现逆转,从而限制了微生物燃料电池的规模化应用,以及它在污废水处理、脱盐等方面的功能.
　　前期研究发现,微生物燃料电池的性能逆转现象与阳极材料的电容性能有关.电极材料的电容越大,越有利于微生物燃料电池的产电性能稳定,换言之,阳极材料电容不足导致产电性能逆转.但是超级电容活性炭的制作工艺繁琐,成本高,且导电性弱,不能满足微生物燃料电池的应用需求.炭黑的导电能力强、化学稳定性高、成本低,但作为微生物燃料电池的阳极则产生产电性能逆转现象.
　　化学修饰(如酸、碱活化或者添加具有赝电容性质的金属氧化物等)可以提高材料的电容性能.低温条件(80 oC)下,对低电容材料—炭黑进行HNO3和KOH的化学活化处理,并在此基础上,进一步用5%Fe3O4修饰,采用辊压工艺,以质量分数为60%的聚四氟乙烯乳液为粘结剂,制作微生物燃料电池的阳极,与空气阴极构建单室微生物燃料电池系统.采用傅里叶变换红外光谱(FTIR)、比表面积测试、材料表面pH和X射线能量分析光谱(EDX)等手段表征炭黑活化前后的物理、化学性质;接触角润湿性测试表征活化前后电极表面的亲疏水性.电化学循环伏安法测试活化前后,电极的电子存储能力.
　　与蒸馏水的pH相比较,材料表面pH分析表明炭黑材料经化学活化处理后,其表面pH无明显变化; FTIR和EDX测试表明化学活化处理使得炭黑表面引入含O(N)官能团;吸附-脱附曲线分析表明化学活化后,炭黑的比表面积减小,微孔与介孔的体积比增加;接触角测试表明炭黑阳极活化处理后,电极表面亲水性增加;循环伏安测试证实,化学活化后的炭黑阳极电容得到0.1–0.8 F/cm2的增长.结合燃料电池的产电性能测试,发现只有当炭黑阳极电容不小于1.1 F/cm2时,微生物燃料电池的产电逆转现象才会消失.炭黑阳极的化学活化方法为微生物燃料电池的性能稳定提供了一种简便、低成本的方法.     

有“生命”的电线:浅析微生物纳米导线电子传递机制及其应用

微生物纳米导线是指在缺少可溶性电子受体的条件下由微生物形成类似菌毛的导电附属物,通过它传递电子是微生物为提高胞外电子传递效率而进化形成的一种有效的电子传递方式。微生物可利用具有高效导电特性的纳米导线将电子传递到远离细胞表面的地方,从而使微生物摆脱了需要直接接触胞外电子受体(Fe(Ⅲ)氧化物或电极)才能传递电子的限制。微生物纳米导线的发现丰富了人们对胞外呼吸多样性的认识,同时其在提高微生物燃料电池产电效率、促进环境中有机污染物的快速降解和生物能源等方面具有重要的应用前景,成为了当前研究的前沿和热点。本文简单介绍了微生物纳米导线的基本特性和产生纳米导线的微生物种类,重点阐述了由Geobacter和Shewanella微生物生成的纳米导线电子传递机制以及其在生物能源和生物修复等方面的应用,并展望了今后的研究重点。     

化学修饰炭黑在微生物燃料电池中的生物产电行为（英文）

研究发现微生物燃料电池从启动到稳定运行的过程中往往存在一种现象,就是在高电流密度下,微生物燃料电池的输出电压会出现逆转,从而限制了微生物燃料电池的规模化应用,以及它在污废水处理、脱盐等方面的功能.前期研究发现,微生物燃料电池的性能逆转现象与阳极材料的电容性能有关.电极材料的电容越大,越有利于微生物燃料电池的产电性能稳定,换言之,阳极材料电容不足导致产电性能逆转.但是超级电容活性炭的制作工艺繁琐,成本高,且导电性弱,不能满足微生物燃料电池的应用需求.炭黑的导电能力强、化学稳定性高、成本低,但作为微生物燃料电池的阳极则产生产电性能逆转现象.化学修饰(如酸、碱活化或者添加具有赝电容性质的金属氧化物等)可以提高材料的电容性能.低温条件(80℃)下,对低电容材料—炭黑进行HNO3和KOH的化学活化处理,并在此基础上,进一步用5%Fe3O4修饰,采用辊压工艺,以质量分数为60%的聚四氟乙烯乳液为粘结剂,制作微生物燃料电池的阳极,与空气阴极构建单室微生物燃料电池系统.采用傅里叶变换红外光谱(FTIR)、比表面积测试、材料表面pH和X射线能量分析光谱(EDX)等手段表征炭黑活化前后的物理、化学性质;接触角润湿性测试表征活化前后电极表面的亲疏水性.电化学循环伏安法测试活化前后,电极的电子存储能力.与蒸馏水的p H相比较,材料表面pH分析表明炭黑材料经化学活化处理后,其表面pH无明显变化;FTIR和EDX测试表明化学活化处理使得炭黑表面引入含O(N)官能团;吸附-脱附曲线分析表明化学活化后,炭黑的比表面积减小,微孔与介孔的体积比增加;接触角测试表明炭黑阳极活化处理后,电极表面亲水性增加;循环伏安测试证实,化学活化后的炭黑阳极电容得到0.1–0.8F/cm2的增长.结合燃料电池的产电性能测试,发现只有当炭黑阳极电容不小于1.1 F/cm2时,微生物燃料电池的产电逆转现象才会消失.炭黑阳极的化学活化方法为微生物燃料电池的性能稳定提供了一种简便、低成本的方法.     

微生物电解电池制氢*

在微生物燃料电池（MFC）的基础上发展而来的微生物电解电池（MEC）为生物制氢提供了一种全新的方法。本文综述了自2005年MEC发明以来取得的研究进展。简要介绍了MEC制氢的基本原理和系统的评价参数;比较了不同MEC系统结构和电极材料对体系产氢效能的影响;讨论了MEC制氢实际应用中存在问题和限制因素;提出了MEC制氢今后的研究思路和发展趋势;展望了MEC在利用生物质制氢和有机废水资源化利用中的应用前景。     

用于生物电化学系统的石墨烯电极新进展

可持续社会的发展需要成本低, 并从废物或废水中提取能源或将能源转化为产品的环境友好技术. 近年兴起的生物电化学系统(BESs)利用微生物催化不同电化学反应, 是将废物或废水中能量转化为电能等多种产品的发展前景广阔的新技术. 当有关反应的吉布斯自由能小于零, 系统输出电能, 此时的BESs即为微生物燃料电池(MFCs); 相反, 若反应的吉布斯自由能为正值, 此时的BESs被称为微生物电解电池(MECs). 随着研究工作的不断深入和拓展, BESs的电极性能已成为制约其应用的瓶颈. 石墨烯以其独特的结构和优异的材料性能在BESs领域, 特别是MFCs中得以应用. 本文参考了最新的文献资料, 综述了石墨烯应用于BESs的发展现状, 包括应用于MFCs的石墨烯电极、掺杂石墨烯电极、担载石墨烯电极, 对其在MECs中可能的应用, 以及未来发展趋势予以展望.     

Bioenergetics and extracellular electron transfer in microbial fuel cells and microbial corrosion

Bioenergetics can be used to analyze the theoretical voltage output of a microbial fuel cell (MFC) and the thermodynamic driving force in microbiologically influenced corrosion (MIC). MFCs involve both inward and outward extracellular electron transfer (EET), whereas only inward EET is behind EET–MIC caused by an electroactive biofilm's harvest of energy from a metal. EET is often rate-limiting, and it is an important process in microbial energy metabolism. EET is critical to the understanding of MFCs and EET–MIC bioelectrochemical processes. Many advances have been made in the past decade on EET by MFC and MIC researchers. Gene manipulations have been used to improve EET in MFCs, leading to enhanced energy output. They have also been used to elucidate the EET processes for better understanding of EET–MIC, which aids in MIC analysis and decision-making of biocide treatment and its efficacy assessment. Researchers are starting to integrate EET knowledge from both fields.     

石墨烯基杂化材料在微生物燃料电池电极中的应用

微生物燃料电池（MFC）是利用生物催化剂将污水有机物中的化学能直接转化为电能的技术,因其功率密度和能量转化效率低,电极制作成本高,限制了其大规模实际应用。因此如何提高电极的催化性能并降低电极制作成本成为MFC的研究重点方向。由于石墨烯基杂化材料具有良好的导电性和催化特性,因此石墨烯基杂化材料成为在MFC电极应用中的热点之一。本文综述了近年来MFC石墨烯基杂化电极材料的最新研究进展,重点讨论了改性石墨烯电极、金属及非金属/石墨烯杂化电极、金属氧化物/石墨烯杂化电极、聚合物/石墨烯杂化电极和石墨烯凝胶电极的设计思路和制备方法及其催化性能,着重分析了石墨烯基阳极和阴极杂化材料对MFC产电性能的影响。最后对石墨烯基杂化材料在MFC应用中存在的问题及研究前景进行了总结和展望。     

A comparative study of energy consumption and physical properties of microfibrillated cellulose produced by different processing methods

Microfibrillated celluloses (MFCs) with diameters predominantly in the range of 10–100 nm liberated from larger plant-based fibers have garnered much attention for the use in composites, coatings, and films due to large specific surface areas, renewability, and unique mechanical properties. Energy consumption during production is an important aspect in the determination of the “green” nature of these MFC-based materials. Bleached and unbleached hardwood pulp samples were processed by homogenization, microfluidization, and micro-grinding, to determine the effect of processing on microfibril and film properties, relative to energy consumption. Processing with these different methods affected the specific surface area of the MFCs, and the film characteristics such as opacity, roughness, density, water interaction properties, and tensile properties. Apparent film densities were approximately 900 kg/m³ for all samples and the specific surface area of the processed materials ranged from approximately 30 to 70 m²/g for bleached hardwood and 50 to 110 m²/g for unbleached hardwood. The microfluidizer resulted in films with higher tensile indices than both micro-grinding and homogenization (148 Nm/g vs. 105 Nm/g and 109 Nm/g, respectively for unbleached hardwood). Microfluidization and micro-grinding resulted in films with higher toughness values than homogenization and required less energy to obtain these properties, offering promise for producing MFC materials with lower energy input. It was also determined that a refining pretreatment required for microfluidization or homogenization can be reduced or eliminated when producing MFCs with the micro-grinder. A summary of the fiber and mechanical energy costs for different fibers and processing conditions with economic potential is presented.     

A microfluidic microbial fuel cell array that supports long-term multiplexed analyses of electricigens

Microbial fuel cells (MFCs) are green energy technologies that exploit microbial metabolism to generate electricity. The widespread implementation of MFC technologies has been stymied by their high cost and limited power. MFC arrays in which device configurations or microbial consortia can be screened have generated significant interest because of their potential for defining aspects that will improve performance featuring high throughput characteristics. However, current miniature MFCs and MFC array systems do not support long-term studies that mimic field conditions, and hence, have limitations in fully characterizing and understanding MFC performances in varieties of conditions. Here, we describe an MFC array device that incorporates microfluidic technology to enable continuous long-term analysis of MFC performance at high throughput utilizing periodic anolyte/catholyte replenishment. The system showed 360% higher power output and 700% longer operating time when compared to MFC arrays without catholyte replenishment. We further demonstrate the utility of the system by reporting its successful use in screening microbial consortia collected from geographically diverse environments for communities that support enhanced MFC performance. Taken together, this work demonstrates that anolyte/catholyte replenishment can significantly improve the long-term performance of microfabricated MFC arrays, and support the characterization of diverse microbial consortia.     

阳极电势对Geobacter sulfurreducens产电性能的影响

以产电模式菌Geobacter sulfurreducens为研究对象接种两瓶型微生物燃料电池(MFC)阳极室, 利用恒电位仪控制阳极电势, 考察了7种电势条件下MFC的启动期、最大功率密度和阳极生物量的变化情况. 研究结果表明, 当阳极电势为-250, -100和50 mV(vs. SCE)时, MFC启动较快, CV曲线和极化曲线表明, 在这3种电势条件下, MFC产电性能增强, 其中阳极电势为-100 mV时, MFC最大功率密度为1.67 W/m³, 比固定外阻条件下启动的MFC最大功率密度提高了5倍. 控制合适的阳极电势可以使阳极生物量提高2.5~3倍.     

Electricity Production and Characterization of High-Strength Industrial Wastewaters in Microbial Fuel Cell

Microbial fuel cells (MFCs) convert electrochemical energy into electrical energy immediately and have a big potential usage for the same time wastewater treatment and energy recovery via electro-active microorganisms. However, MFCs must be efficiently optimized due to its limitations such as high cost and low power production. Finding new materials to increase the cell performance and reduce cost for MFC anodes is mandatory. In the first step of this study, different inoculation sludges such as anaerobic gum industry wastewater, anaerobic brewery wastewater and anaerobic phosphate were tested, and MFC that was set up with anaerobic gum industry wastewater inoculation sludge exhibited the highest performance. In the second step of this study, various wastewaters such as chocolate industry, gum industry and slaughterhouse industry were investigated for anode bacteria sources. Several electrochemical techniques have been employed to elucidate how wastewaters affect the MFCs’ performance. Among all the mentioned wastewaters, the best performance was achieved by the MFCs fed with slaughterhouse wastewater; this device produced a maximum power density of 267 mW·m^?2.     

Microfuel cells: Modern state and future development (Review)

Literature sources of the last 15 years were analyzed and the results were considered for the studies carried out in one of the directions of hydrogen power engineering of the most current interest: development of portable low-power fuel cells (microfuel cells, MFCs). MFCs with high power density and high efficiency are used as a basis for a new generation of power sources for various stand-alone electronic devices. The latest silicon micro- and nanotechnologies are considered, same as the technologies for obtaining nanostructured catalysts and problems regarding development of MFCs with the power of 0.5–20 W, methods of catalytic layers application in MFCs, choice of fuel, and methods of supplying it into MFCs, and MFC water managemen and temperature control. Special attention was paid to borohydride MFCs, combined (hybrid) systems, and MFCs with a mixed reagent. The results of electrochemical tests of MFC layouts are presented.     

The effect of chemical composition on microfibrillar cellulose films from wood pulps: water interactions and physical properties for packaging applications

The interactions with water and the physical properties of microfibrillated celluloses (MFCs) and associated films generated from wood pulps of different yields (containing extractives, lignin, and hemicelluloses) have been investigated. MFCs were produced by combining mechanical refining and a high pressure treatment using a homogenizer. The produced MFCs were characterized by morphology analysis, water retention, hard-to-remove water content, and specific surface area. Regardless of chemical composition, processing to convert macrofibrils to microfibrils resulted in a decrease in water adsorption and water vapor transmission rate, both important properties for food packaging applications. After homogenization, MFCs with high lignin content had a higher water vapor transmission rate, even with a higher initial contact angle, hypothesized to be due to large hydrophobic pores in the film. A small amount of paraffin wax, less than 10%, reduced the WVTR to a similar value as low density polyethylene. Hard-to-remove water content correlated with specific surface area up to approximately 50 m²/g, but not with water retention value. The drying rate of the MFCs increased with the specific surface area. Hornified fibers from recycled paper also have the potential to be used as starting materials for MFC production as the physical and optical properties of the films were similar to the films from virgin fibers. In summary, the utilization of lignin containing MFCs resulted in unique properties and should reduce MFC production costs by reducing wood, chemical, and energy requirements.     

Effect of draw ratio on the microstructure, thermal, tensile and dynamic rheological properties of insitu microfibrillar composites

Microfibrillar composites (MFCs) were prepared using different draw/stretch ratios [viz. 2, 5, 8 and 10] from polypropylene/polyethylene terephthalate (PP/PET) blends. Scanning electron microscopy [SEM] images revealed that PET microfibrils were highly oriented after melt blending and drawing. After the conversion of drawn (stretched) blends to MFCs the PET microfibrils were found to be randomly distributed in the PP matrix. The tensile strength and modulus of the MFCs were found to be higher for the samples drawn at stretch ratios 5 and 8 on account of the long PET microfibrils they possessed. The non isothermal crystallization behaviour of the neat blend (as extruded), stretched blend and the MFC was compared. The oriented PET fibrils in the stretched blend were found to have a greater nucleating effect for the crystallization of PP than the spherical PET particles in the neat blend and randomly oriented short PET fibrils in the MFC. Dynamic rheology studies indicated the storage modulus and loss modulus of MFCs were enhanced as draw ratio increases up to an optimized level beyond which they decrease. When the draw ratio increased up to the optimized level the MFCs tended to be more viscous, especially at low frequency, whereas further increasing the draw ratio resulted in a decrease in the complex viscosity. The microfibrils of PET in the MFC were found to perturb the relaxation of molten PP matrix.