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。     

Microbial Electrolysis Cells for Hydrogen Production

Microbial electrolysis cells (MECs) present an attractive route for energy-saving hydrogen (H₂) production along with treatment of various wastewaters, which can convert organic matter into H₂ with the assistance of microbial electrocatalysis. However, the development of such renewable technologies for H₂ production still faces considerable challenges regarding how to enhance the H₂ production rate and to lower the energy and the system cost. In this review, we will focus on the recent research progress of MEC for H₂ production. First, we present a brief introduction of MEC technology and the operating mechanism for H₂ production. Then, the electrode materials including some typical electrocatalysts for hydrogen production are summarized and discussed. We also highlight how various substrates used in MEC affect the associated performance of hydrogen generation. Finally we presents several key scientific challenges and our perspectives on how to enhance the electrochemical performance.     

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。     

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.     

Graphene Oxide/Carbon Nanotube Composite Hydrogels—Versatile Materials for Microbial Fuel Cell Applications

Carbonaceous nanocomposite hydrogels are prepared with an aid of a suspension polymerization method and are used as anodes in microbial fuel cells (MFCs). (Poly N‐Isopropylacrylamide) (PNIPAM) hydrogels filled with electrically conductive carbonaceous nanomaterials exhibit significantly higher MFC efficiencies than the unfilled hydrogel. The observed morphological images clearly show the homogeneous dispersion of carbon nanotubes (CNTs) and graphene oxide (GO) in the PNIPAM matrix. The complex formation of CNTs and GO with NIPAM is evidenced from the structural characterizations. The effectual MFC performances are influenced by combining the materials of interest (GO and CNTs) and are attributed to the high surface area, number of active sites, and improved electron‐transfer processes. The obtained higher MFC efficiencies associated with an excellent durability of the prepared hydrogels open up new possibilities for MFC anode applications.

     

微生物燃料电池

微生物燃料电池 (Microbial Fuel Cells,MFCs) 是一种利用微生物作为催化剂,将燃料中的化学能直接转化为电能的装置。本文首先简要介绍了MFCs 的发展简史和基本原理,针对MFCs 产电性能低的现状,分别从产电微生物、电池结构、质子交换膜(PEM)、电极以及电解液等方面着重综述了近几年有关提高MFCs 产电性能的研究进展。最后介绍了关于MFCs 的另一些有趣的研究方向：植物MFCs,生物阴极MFCs,以及污水脱氮和有毒废水处理。     

Nanostructured Graphene/TiO2 Hybrids as High‐Performance Anodes for Microbial Fuel Cells

A new nanostructured graphene/TiO₂ (G/TiO₂) hybrid was synthesized by a facile microwave‐assisted solvothermal process in which amorphous TiO₂ was assembled on graphene in situ. The resulting G/TiO₂ hybrids were characterized by XRD, SEM, TEM, Raman spectroscopy, and N₂ adsorption/desorption analysis. The electrochemical properties of the hybrids as anode materials for Shewanella‐inoculated microbial fuel cells (MFCs) were studied for the first time, and they proved to be effective in improving MFC performance. The significantly improved bacterial attachment and extracellular electron‐transfer efficiency could be attributed to the high specific surface area, active groups, large pore volume, and excellent conductivity of the nanostructured G/TiO₂ hybrid, and this suggests that it could be a promising candidate for high‐performance MFCs.     

微生物燃料电池生物阴极

微生物燃料电池(microbial fuel cells, MFCs)利用微生物处理废水的同时产电,是一种清洁可再生能源技术。近年来新兴起的生物阴极是指阴极室中的功能微生物附着在电极表面形成生物膜,电子由电极传递给微生物并发生相应的生物电化学反应;是微生物燃料电池研究的一个重要方向。本文根据厌氧、好氧操作体系的不同将生物阴极进行分类;归纳总结了微生物组成、电极和分隔材料的研究进展,探讨了生物阴极在去除污染物和生成高附加值产品中的实际应用,并提出了其将来发展的可能方向。     

Functional Nanomaterial-Modified Anodes in Microbial Fuel Cells: Advances and Perspectives

Microbial fuel cell (MFC) is a promising approach that could utilize microorganisms to oxidize biodegradable pollutants in wastewater and generate electrical power simultaneously. Introducing advanced anode nanomaterials is generally considered as an effective way to enhance MFC performance by increasing bacterial adhesion and facilitating extracellular electron transfer (EET). This review focuses on the key advances of recent anode modification materials, as well as the current understanding of the microbial EET process occurring at the bacteria-electrode interface. Based on the difference in combination mode of the exoelectrogens and nanomaterials, anode surface modification, hybrid biofilm construction and single-bacterial surface modification strategies are elucidated exhaustively. The inherent mechanisms may help to break through the performance output bottleneck of MFCs by rational design of EET-related nanomaterials, and lead to the widespread application of microbial electrochemical systems.     

再生燃料电池的研究与应用

与传统二次电池（铅酸蓄电池、锂电池）相比,再生燃料电池在储能时间、能量密度、使用寿命和环境保护方面占有优势,可广泛应用于航天、军事领域和现场蓄能系统。本文介绍了再生燃料电池的原理、分类和应用情况,详细阐述了再生燃料电池双效电极和双效电极催化剂的制备方法以及水热管理的研究进展,指出再生燃料电池的不足之处并进行了展望。     

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.     

从电化学和微生物学角度分析微生物燃料电池处理硫污染物的机理

微生物燃料电池(Microbial fuel cells,MFCs)是一种有前景的去除废水中硫污染物的技术。本文在生物膜电极反应机理的基础上,讨论电极反应和微生物在MFCs处理硫污染物过程中的作用,论证了其处理机制和影响因素,总结了反应器构型、分离器类型、电极材料和催化剂,以及硫的回收和电极再生。此外,通过核算对比MFCs和典型的厌氧生物技术处理含硫废水的成本和收益对MFCs去除废水中硫污染物的可行性进行了评估。     

Mo2C/Reduced Graphene Oxide Composites with Enhanced Electrocatalytic Activity and Biocompatibility for Microbial Fuel Cells

A simple, cost-effective strategy was developed to effectively improve the electron transfer efficiency as well as the power output of microbial fuel cells (MFCs) by decorating the commercial carbon paper (CP) anode with an advanced Mo₂C/reduced graphene oxide (Mo₂C/RGO) composite. Benefiting from the synergistic effects of the superior electrocatalytic activity of Mo₂C, the high surface area, and prominent conductivity of RGO, the MFC equipped with this Mo₂C/RGO composite yielded a remarkable output power density of 1747±37.6 mW m⁻², which was considerably higher than that of CP-MFC (926.8±6.3 mW m⁻²). Importantly, the composite also facilitated the formation of 3D hybrid biofilm and could effectively improve the bacteria–electrode interaction. These features resulted in an enhanced coulombic efficiency up 13.2 %, nearly one order of magnitude higher than that of the CP (1.2 %).     

Graphene/Fe3O4 Nanocomposites as Efficient Anodes to Boost the Lifetime and Current Output of Microbial Fuel Cells

The enhancement of microbial activity and electrocatalysis through the design of new anode materials is essential to develop microbial fuel cells (MFCs) with longer lifetimes and higher output. In this research, a novel anode material, graphene/Fe₃O₄ (G/Fe₃O₄) composite, has been designed for Shewanella ‐inoculated MFCs. Because the Shewanella species could bind to Fe₃O₄ with high affinity and their growth could be supported by Fe₃O₄, the bacterial cells attached quickly onto the anode surface and their long‐term activity improved. As a result, MFCs with reduced startup time and improved stability were obtained. Additionally, the introduction of graphene not only provided a large surface area for bacterial attachment, but also offered high electrical conductivity to facilitate extracellular electron transfer (EET). The results showed that the current and power densities of a G/Fe₃O₄ anode were much higher than those of each individual component as an anode.     

Platinum Group Metal–free Catalysts for Hydrogen Evolution Reaction in Microbial Electrolysis Cells

Hydrogen gas is a green energy carrier with great environmental benefits. Microbial electrolysis cells (MECs) can convert low‐grade organic matter to hydrogen gas with low energy consumption and have gained a growing interest in the past decade. Cathode catalysts for the hydrogen evolution reaction (HER) present a major challenge for the development and future applications of MECs. An ideal cathode catalyst should be catalytically active, simple to synthesize, durable in a complex environment, and cost‐effective. A variety of noble‐metal free catalysts have been developed and investigated for HER in MECs, including Nickel and its alloys, MoS₂, carbon‐based catalysts and biocatalysts. MECs in turn can serve as a research platform to study the durability of the HER catalysts. This personal account has reviewed, analyzed, and discussed those catalysts with an emphasis on synthesis and modification, system performance and potential for practical applications. It is expected to provide insights into the development of HER catalysts towards MEC applications.     

绿脓杆菌阳极的微生物燃料电池含溶解氧性能研究

本文研究了绿脓杆菌分泌的电子中介体绿脓菌素与电极之间的反应,并探讨了溶解氧的影响. 通过循环伏安曲线、测试电极开路电位等方法,确定绿脓菌素阳极反应是受扩散控制的可逆反应. 菌液的溶解氧浓度在一定范围内（0 ~ 1.6 mg.L^-1）对绿脓菌素和电极之间的反应影响不大. 微生物燃料电池的极化曲线表明,当溶解氧为1.6 mg.L^-1时,微生物燃料电池输出电流下降了7%,对绿脓杆菌阳极的微生物燃料电池影响不大.     

Using 3D Composite Electrode Materials for Electricity Generation from Swine Wastewater in a Dual‐Chamber Microbial Fuel Cells

Swine wastewater has a high concentration of organic matter, suspended solids, and higher ammonia nitrogen, odor, complex polluting ingredients, and large emissions. A two‐chambered cubic microbial fuel cell (MFC) was used to evaluate the effect of a novel three‐dimensional (3D ) electrode made of 3D iron composites and 3D stainless composites on the electricity generation. Swine wastewater with a total chemical oxygen demand (TCOD ) of 3688 ± 300 mg/L was used as the feedstock in the anode chamber. The MFC reactor was incubated with an initial pH of 7.0 in an air shaker with a temperature of ~35°C and 100 rpm in the fed‐batch mode. A fixed external resistance (R ) of 100 Ω was connected between the electrodes, and the closed‐circuit potentials of the MFCs were recorded every 5 min. The results showed that using an iron–carbon fiber composite 3D electrode resulted in a peak electricity generation of 321 mV on the first 2 days and maintained a stable voltage of 163 mV during the second to sixth days. The COD removal efficiency could reach 75%. Using a stainless–carbon fiber 3D electrode could generate a peak voltage of only 29.5 mV and a stable voltage of 15.2 mV with a COD removal efficiency of 54%.     

Composite Cathode Based on Redox-Reversible Nb2TiO7 for Direct High-Temperature Steam Electrolysis

Ni/YSZ fuel electrodes can only operate under strongly reducing conditions for steam electrolysis in an oxide-ion-conducting solid oxide electrolyzer (SOE). In atmosphere with a low content of H₂ or without H₂, cathodes based on redox-reversible Nb₂TiO₇ provide a promising alternative. The reversible changes between oxidized Nb₂TiO₇ and reduced Nb_1.33Ti_0.67O₄ samples are systematically investigated after redox-cycling tests. The conductivities of Nb₂TiO₇ and reduced Nb_1.33Ti_0.67O₄ are studied as a function of temperature and oxygen partial pressure and correlated with the electrochemical properties of the composite electrodes in a symmetric cell and SOE at 830 oC. Steam electrolysis is then performed using an oxide-ion-conducting SOE based on a Nb_1.33Ti_0.67O₄ composite fuel electrode at 830 oC. The current-voltage and impedance spectroscopy tests demonstrate that the reduction and activation of the fuel electrode is the main process at low voltage; however, the steam electrolysis dominates the entire process at high voltages. The Faradic efficiencies of steam electrolysis reach 98.9% when 3%H₂O/Ar/4%H₂ is introduced to the fuel electrode and 89% for that with introduction of 3%H₂O/Ar.     

金属离子在微生物燃料电池中的行为

在废水处理方面,微生物燃料电池具有在净化废水的同时回收能源或有价值化学品等突出优点,已经成为人们研究的热点。在微生物燃料电池中,金属离子能直接或者间接参与阳极和阴极过程,其对溶液的电导率、反应器的内阻和功率密度、产电微生物的活性等都有重要影响。本文综述了金属离子参与微生物燃料电池的机制及其影响因素,并且介绍了微生物燃料电池在去除废水或者固体废弃物中重金属离子方面的优势和发展前景。     

Bioelectrochemical Systems for Measuring Microbial Cellular Functions

In bioelectrochemical systems (BESs), living microorganisms are capable of converting the chemical energy of degradable organic matters into bioelectricity. The electrical current outputs are dependent on the microbial cell viability and the biodegradation rates. Therefore, monitoring the current generative through the BES is promising for the microbial activity assessments. As compared to conventional microbiological methods, BESs are considered as non‐invasive techniques that offer rapid and sensitive detection of cellular functions (extra‐ and/or intracellular). Therefore, several progressions were made in the last 100 years in order to develop effective BESs. In this review, the involvements of materials sciences, microbiology, and electrochemistry in the effective designing and developments of BESs were intensively discussed. Due to the nanotechnology revolutions, manipulation of electrode materials led to the creation of different BES generations. Therefore, the impact of nanomaterials on the developments of the second and third generations of BESs is still the outlook of this promising research area.