生物阴极微生物燃料电池不同阴极材料产电特性

以葡萄糖(COD初始浓度为2000 mg/L, COD为化学需氧量)为阳极燃料底物, 考察了碳纤维刷和柱状活性碳颗粒作为生物阴极微生物燃料电池(MFC)阴极材料的产电性能. 研究结果表明, 碳纤维刷MFC的启动时间比碳颗粒MFC的长, 达到稳定状态后的恒负载(300 Ω)电压(0.324 V)比碳颗粒阴极MFC的(0.581 V)低. 极化分析结果表明, 碳纤维刷MFC和碳颗粒MFC的最大功率密度分别为24.7 W/m3(117.2 A/m3)和50.3 W/m3(167.2 A/m3). 电化学交流阻抗谱(EIS)测定结果表明, 由于电极材料对微生物生长和分布状态存在不同的影响, 使得碳纤维刷阴极MFC的极化内阻大于碳颗粒阴极MFC的极化内阻.     

不锈钢网阴极微生物燃料电池的产电性能研究

构建了一个以曝气池污泥为阳极接种微生物、碳毡为阳极、无任何修饰的不锈钢网为阴极的双室微生物燃料电池. 通过输出电压、功率密度以及电化学阻抗等考察了阴极面积对电池产电性能的影响,并对电池的长期运行稳定性进行评价. 研究结果表明,不锈钢网作为微生物燃料电池的阴极性能稳定. 当不锈钢网面积为2 × 2 cm²时,最大输出电压达到0.411 V,功率密度为0.303 W•m^-2,内阻841 Ω,极化内阻80 Ω. 增大阴极面积至2 × 4 cm²,最大输出电压能达到0.499 V,内阻减小至793 Ω. 不锈钢网价格便宜,具有长期运行稳定性,适宜做MFCs的阴极.     

Electrochemically Prepared Manganese Oxide as a Cathode Material for a Microbial Fuel Cell

This work describes the construction of a mediatorless microbial fuel cell (MFC) using the microorganism Acetobacter aceti as the biocatalyst in the anode compartment with glucose as a fuel. The periplasmic membrane bound pyrroloquinoline quinone (PQQ) containing enzymes of these genera provide fast and highly efficient oxidation of a wide variety of substrates and helps in the direct routing of electrons to the anode. We describe our preliminary findings with regard to the use of electrochemically deposited manganese oxide films on carbon substrates as cathode materials in MFCs. Manganese oxide was electrochemically deposited on carbon paper in the presence and in the absence of the surfactant, sodium lauryl sulfate (SLS). Electrochemical characterizations of the electrodeposited films are carried out by cyclic voltammetry and impedance spectroscopy. Structural characterization of the film is carried out by XRD, XPS, and SEM. The XPS studies reveal that the presence of Mn⁴⁺ (as MnO₂) in the absence of SLS and Mn^3+/2+ (as Mn₃O₄or Mn₂O₃ or MnOOH) ion in the presence of SLS. The power output obtained from MnO₂ cathode was 666 ± 9 mW m^?3 and it is the highest value reported for MFCs with cubical configuration with the same cathode.     

Power Generation Capabilities of Microbial Fuel Cells with Different Oxygen Supplies in the Cathodic Chamber

Two microbial fuel cells (MFCs) inoculated with activated sludge of a wastewater treatment plant were constructed. Oxygen was provided by mechanical aeration in the cathodic chamber of one MFC, whereas it was obtained by the photosynthesis of algae in the other. Electrogenic capabilities of both MFCs were compared under the same operational conditions. Results showed that the MFC with mechanical aeration in the cathodic chamber displayed higher power output than the one with photosynthesis of algae. Good linear relationship between power density and chemical oxygen demand (COD) loading rate was obtained only on the MFC with mechanical aeration. Furthermore, the relationships between power density and effluent COD and between Coulombic efficiency and COD loading rate can only be expressed as binary quadratic equations for the MFC with mechanical aeration and not for the one with photosynthesis of algae.     

Reversible Solid Oxide Fuel Cell for Power Accumulation and Generation

The anodic and cathodic polarization dependences for the oxygen electrode based on lanthanum-strontium manganite and the fuel Ni-cermet electrode are studied in the temperature range of 700–900°С in gas media that correspond to working conditions of a reversible fuel cell. The temporal behavior of these electrodes is studied in the course of periodic polarity changes of current with the density of 0.5 A/cm². The electrode overvoltage is shown to be about 0.1 V in modes of power generation and water electrolysis at 900°С and the current density of 0.5 A/cm². A single electrolyte supported tubular solid-oxide fuel cell was fabricated and tested in the fuel-cell and hydrogen-generation modes. It is found that at 900°С and overvoltage of 0.7 V, the cell generates the specific electric power of 0.4 W/cm² when the 50% H2 + 50% H₂O gas mixture is used as the fuel and air is used as the oxidizer. At the water electrolysis with the current density of 0.5 A/cm², which under normal conditions corresponds to generation of about 0.2 and 0.1 L/h of hydrogen and oxygen, respectively, the consumed power is about 0.55 W/cm². The efficiency of the conversion cycle electric power–hydrogen–electric power is 70–75%.     

生物膜电极在以苯酚为燃料的微生物燃料电池中的应用

以苯酚为燃料, 生物膜电极为负极, Ti/SnO₂-Sb₂O₅/PbO₂电极为正极, 构建了双室微生物燃料电池. 利用微电流驯化法和自然驯化法分别制备了生物膜电极, 研究了微生物的挂膜方法、 挂膜时间和负极基底材料种类对微生物燃料电池产电能力的影响. 结果表明, 微电流驯化法优于自然驯化法, 微电流驯化法制备的生物膜电极更利于电池的产电; 微生物的挂膜时间为8 d时, 电池的产电能力最高, 其最大输出功率密度达到39 mW/m²; 不同基底材料生物膜电极所组建的微生物燃料电池产电能力高低顺序为碳毡>石墨>钛网>泡沫钛.     

Construction and Operation of Microbial Fuel Cell with Chlorella vulgaris Biocathode for Electricity Generation

In this study, a modified microbial fuel cell (MFC) with a tubular photobioreactor (PHB) configuration as a cathode compartment was constructed by introducing Chlorella vulgaris to the cathode chamber used to generate oxygen in situ. Two types of cathode materials and light/dark cycles were used to test the effect on MFC with algae biocathode. Results showed that the use of algae is an effective approach because these organisms can act as efficient in situ oxygenators, thereby facilitating the cathodic reaction. Dissolved oxygen and voltage output displayed a clear light positive response and were drastically enhanced compared with the abiotic cathode. In particular, carbon paper-coated Pt used as a cathode electrode increased voltage output at a higher extent than carbon felt used as an electrode. The maximum power density of 24.4 mW/m² was obtained from the MFC with algae biocathode which utilized the carbon paper-coated Pt as the cathode electrode under intermittent illumination. This density was 2.8 times higher than that of the abiotic cathode. Continuous illumination shortened the algal lifetime. These results demonstrated that intermittent illumination and cathode material-coated catalyst are beneficial to a more efficient and prolonged operation of MFC with C. vulgaris biocathode.     

氧化铈作为阴极催化剂在直接硼氢化物燃料电池中的应用

研究以氧化铈(CeO2)作为直接硼氢化物燃料电池(DBFC)阴极催化剂的性能.结果表明:氧化铈对氧还原具有良好的催化效能,但对BH4-离子水解没有明显的促进作用,而且还能抑制它在正极的氧化.以氧化铈为阴极催化剂组装成的模拟单室燃料电池在常温下的最高功率密度为67.8mW·cm-2,运行稳定.     

Evaluation of Kefir as a New Anodic Biocatalyst Consortium for Microbial Fuel Cell

Kefir, a combined consortium of bacteria and yeast encapsulated by a polymeric matrix of exopolysaccharides, was used as anodic biocatalyst in a two-chamber microbial fuel cell (MFC). Fermentation was followed during 72 h and polarization curves were obtained from linear sweep voltammetry. The effect of methylene blue as charge-transfer mediator in the kefir metabolism was evaluated. UV/Vis spectrophotometry and cyclic voltammetry were applied to evaluate the redox state of the mediator and to characterize the electrochemical activity, whereas current interruption was used for internal resistance determination. Aiming to establish a relationship between the microbial development inside the anodic chamber with the generated power in the MFC, total titratable acidity, pH, viscosity, carbohydrate assimilation, and microbial counting were assayed. The kefir-based MFC demonstrated a maximum power density of 54 mW m^?2 after 24 h fermentation, revealing the potential use of kefir as a biocatalyst for microbial fuel cells.     

纳米Au粒子作为直接硼氢化钠-过氧化氢燃料电池阴极催化剂

采用浸渍还原法制备了纳米Au/C, 并将其用作直接硼氢化钠-过氧化氢燃料电池阴极催化剂. 通过X-射线衍射(XRD)和透射电镜(TEM)对催化剂进行结构和形貌分析, 结果表明10～20 nm的纳米Au粒子均匀地分散在Vulcan XC-72R碳黑表面上. 循环伏安测试表明, 在0.5 mol•L－1 H2SO4和2 mol•L－1 H2O2混合溶液中, 纳米Au/C在0.85 V处表现较强的不可逆还原电流. 以纳米Au/C为阴极催化剂, AB5储氢合金为阳极催化剂制成直接硼氢化钠-过氧化氢燃料电池. 电池在30 ℃下的最大功率密度可达到78.6 mW•cm－2. 当电池工作温度升高至50 ℃时, 电池的最大功率密度超过120 mW•cm－2. 此外, 研究了阴极溶液中H2SO4和H2O2浓度对电池性能的影响. 当阴极溶液中H2SO4浓度小于0.5 mol•L－1时, 酸浓度对电池性能影响较大; H2O2浓度对电池性能影响较小. 确定了阴极溶液中H2SO4和H2O2的最佳浓度分别为0.5和2 mol•L－1.     

直接硼氢化物燃料电池阴极催化剂的研究进展

缓慢的阴极氧还原动力学和催化剂稳定性是制约直接硼氢化物燃料电池商业化的关键因素之一。为此,研究者在提高催化剂的催化活性与稳定性和降低催化剂成本方面开展了大量的研究工作。本文在简要介绍直接硼氢化物燃料电池的工作原理和阴极氧还原反应机理的基础上,从催化剂性能和反应机理角度综述了近年来直接硼氢化物燃料电池中贵金属和非贵金属两类阴极催化剂的主要研究进展,指出了阴极催化剂研究所面临的问题,同时提出了阴极催化剂研究的新的发展方向。     

氧化镧作为直接硼氢化物燃料电池阴极催化剂的研究

通过采用线性电势扫描(LSV)和恒电流计时电势扫描方法对氧化镧作为直接硼氢化物燃料电池阴极催化剂的电化学性能进行了研究.实验结果表明:在单室燃料电池体系中,氧化镧对氧还原具有良好的活性,同时在强碱溶液中对硼氢根离子具有很强的稳定性且对硼氢根的水解没有任何促进作用.以镍基储氢合金作为电池的阳极催化剂组装成简单的单室燃料电池,电池的开路电压达到1.052 V,在常温下(21℃),电池于0.491 V获得最高功率密度65.25 mW·cm-2,电池运行稳定.     

污泥水解液基质微生物燃料电池的研究

研究不同污泥热水解时间下水解液特性及其对微生物燃料电池（MFC）产电的影响.水解时间由2 h增至96 h,水解液pH基本稳定于7.4 ~ 8.0;水解时间增加,其电导率逐渐提高至2.53 mS·cm^-1,COD浓度和碱度也不断增加,水解液的缓冲能力不断得到提高.MFC最大功率密度达到25 W·m^-3,COD去除率呈现先增后降,水解6 h时达到最大（47%）;库仑效率在预水解4 h时达到最高（71%）.阳极室pH下降可归因于NH⁴⁺、Na⁺、Ca²⁺、Mg²⁺等阳离子迁移,其中NH⁴⁺的迁移量最大.     

Enhanced Performance of a Microbial Fuel Cell with a Capacitive Bioanode and Removal of Cr (VI) Using the Intermittent Operation

This study investigated a system which simultaneously produced electricity and stored energy in the MFC integrated MnO₂-modified capacitive bioanode. Compared to the noncapacitive anode, the maximum power density of MFC with MnO₂-modified bioanode reached 16.47 W m^?3, which was 3.5 times higher than that of the bare anode (4.71 W m^?3). During the charging-discharging experiment, the MFC with a capacitance bioanode has a higher average peak current density of 5.06 mA cm^?2 and 36 times larger than that with the bare bioanode. With the capacitive electrode, it is possible to let the MFC at the same time for production and storage of renewable electricity. Then two different operations (intermittent operation and continuous operation) of the MFC with a capacitive bioanode were studied to degrade Cr (VI) in cathode chamber. Results showed that the Cr (VI) removal rates of intermittent operation are much higher than that of continuous operation under the same time in the closed circuit state. This is due to the good ability of storing and releasing electron of the biological capacitor with MnO₂ modified material. And this study showed that MFC with a capacitive bioanode is better adapted to treat heavy metal pollutants by intermittent mode.     

基于碳化钼的燃料电池阴极催化剂的制备及其作用机理

以 Mo2C/VC 作为质子交换膜燃料电池氧还原催化剂, 并采用单电池和电化学循环伏安扫描技术考察了其氧还原活性,同时结合 X 射线衍射和 X 射线光电子能谱对其电催化机理进行初步分析. 结果表明, Mo2C/VC 对氧还原也具有电催化活性, 在 0.34, 0.45 和 0.55 V 处出现三对可逆的氧化还原峰. Mo2C/VC 的体相为β-Mo2C, 表相为+δ价(5 ≤δ≤ 6)的 MoOxCy 和 MoOz. Mo2C/VC 的电催化性能可能是由于其表面钝化物种(MoOxCy 和 MoOz)的氧化还原, 以及氧在 Mo2C 晶格中的迁入和迁出引起的.     

A Robust One‐Compartment Fuel Cell with a Polynuclear Cyanide Complex as a Cathode for Utilizing H2O2 as a Sustainable Fuel at Ambient Conditions

A robust one‐compartment H₂O₂ fuel cell, which operates without membranes at room temperature, has been constructed by using a series of polynuclear cyanide complexes that contain Fe, Co, Mn, and Cr as cathodes, in sharp contrast to conventional H₂ and MeOH fuel cells, which require membranes and high temperatures. A high open‐circuit potential of 0.68 V was achieved by using Fe₃[{Co^III(CN)₆}₂] on a carbon cloth as the cathode and a Ni mesh as the anode of a H₂O₂ fuel cell by using an aqueous solution of H₂O₂ (0.30 M , pH 3) with a maximum power density of 0.45 mW cm^?2. The open‐circuit potential and maximum power density of the H₂O₂ fuel cell were further increased to 0.78 V and 1.2 mW cm^?2, respectively, by operation under these conditions at pH 1. No catalytic activity of Co₃[{Co^III(CN)₆}₂] and Co₃[{Fe^III(CN)₆}₂] towards H₂O₂ reduction suggests that the N‐bound Fe ions are active species for H₂O₂ reduction. H₂O₂ fuel cells that used Fe₃[{Mn^III(CN)₆}₂] and Fe₃[{Cr^III(CN)₆}₂] as the cathode exhibited lower performance compared with that using Fe₃[{Co^III(CN)₆}₂] as a cathode, because ligand isomerization of Fe₃[{M^III(CN)₆}₂] into (FeM₂)[{Fe^II(CN)₆}₂] (M=Cr or Mn) occurred to form inactive Fe? C bonds under ambient conditions, whereas no ligand isomerization of Fe₃[{Co^III(CN)₆}₂] occurred under the same reaction conditions. The importance of stable Fe²⁺? N bonds was further indicated by the high performance of the H₂O₂ fuel cells with Fe₃[{Ir^III(CN)₆}₂] and Fe₃[{Rh^III(CN)₆}₂], which also contained stable Fe²⁺? N bonds. The stable Fe²⁺? N bonds in Fe₃[{Co^III(CN)₆}₂], which lead to high activity for the electrocatalytic reduction of H₂O₂, allow Fe₃[{Co^III(CN)₆}₂] to act as a superior cathode in one‐compartment H₂O₂ fuel cells.     

微生物燃料电池在传感分析中的应用及研究进展

微生物燃料电池(Microbial fuel cell,MFC)是一种利用微生物将化学能直接转化为电能的装置.近年来,除改善微生物燃料电池的输出性能外,研究者也不断开发其在传感分析中的应用.基于微生物燃料电池的传感分析装置无需外加电源,具有操作简单、可连续检测等优点,是一种极具应用前景的传感分析技术.本文依据这些传感分析装置的用途进行分类,主要综述了微生物燃料电池在检测分析生化需氧量(BOD)、挥发性脂肪酸、毒性物质、微生物活性和数量以及其它方面的研究,并对其发展趋势和应用前景进行了展望.     

Microbial Fuel Cells: The Effects of Configurations,Electrolyte Solutions,and Electrode Materials on Power Generation

This objective of this study is to conduct a systematic investigation of the effects of configurations, electrolyte solutions, and electrode materials on the performance of microbial fuel cells (MFC). A comparison of voltage generation, power density, and acclimation period of electrogenic bacteria was performed for a variety of MFCs. In terms of MFC configuration, membrane-less two-chamber MFCs (ML-2CMFC) had lower internal resistance, shorter acclimation period, and higher voltage generation than the conventional two-chamber MFCs (2CMFC). In terms of anode solutions (as electron donors), the two-chamber MFCs fed with anaerobic treated wastewater (AF-2CMFCs) had the power density 19 times as the two-chamber MFCs fed with acetate (NO₃ ⁻2CMFCs). In terms of cathode solutions (as electron acceptors), AF-2CMFCs with ferricyanide had higher voltage generation than that of ML-2CMFCs with nitrate (NO₃ ⁻ML-2CMFCs). In terms of electrode materials, ML-2CMFCs with granular-activated carbon as the electrode (GAC-ML-2CMFCs) had a power density 2.5 times as ML-2CMFCs with carbon cloth as the electrode. GAC-ML-2CMFCs had the highest columbic efficiency and power output among all the MFCs tested, indicating that the high surface area of GAC facilitate the biofilm formation, accelerate the degradation of organic substrates, and improve power generation.     

Calculating a Characteristic Bulk Current Density in the Cathode of a Hydrogen-Oxygen Fuel Cell with a Solid Polymer Electrolyte

The magnitude of currents of electrodes in hydrogen-oxygen fuel cells of all types is shown to be fully determined by values of the effective coefficient of gas diffusion, the effective coefficient of ionic conduction, and the characteristic bulk current density. The characteristic bulk current density is estimated in two versions for cathodes with Nafion: the catalyst is distributed in the bulk of substrate grains or at their external surface. The currents commensurate with those observed in experiments are given only by the second version. Means of computer-aided simulation are used to imitate the formation of fractal films composed of the catalyst particles on the surface substrate grains. The simulation means made it possible to link the magnitude of the specific surface area of platinum particles with its weight content in substrate grains. Electrochemical characteristics of the cathode with Nafion-the potential dependence of the optimum magnitude of the overall current and the thicknesses of the active layer and the weight of platinum in it, as well as the magnitudes of the optimum current generated by a unit weight of platinum—are calculated. A notion of “ norm” is introduced for the characteristic bulk current density of the cathode. 1 × 10^?3 A cm^?3 is the electrochemical-process intensity, which the technology of preparation of active layers of cathodes can provide at this stage in the development of fuel cells with a solid polymer electrolyte.     

Ag3PO4光催化耦合微生物燃料电池去除罗丹明B

以硝酸银、磷酸钠为原料,一步沉淀法制备了Ag₃PO₄可见光光催化剂,用硅溶胶将其负载于不锈钢丝网上,经干燥得到光催化电极。以此光催化电极和碳棒分别作为阴极、阳极,在阳极室加入负载生物产电菌的活性炭颗粒,建立光催化耦合微生物燃料电池反应器。以罗丹明B(RhB)为模型污染物,考察了光照、底物浓度、pH值等对污染物去除效率与电池产电性能的影响。结果显示:在100 W卤素灯光照下、外接500Ω电阻、pH=10、微生物量1.5倍,反应4 h可去除92%的(50 mg·L^-1、200 mL)RhB;此时电池输出电压和功率密度分别为124 mV、34.9 mW·m^-2。5次重复实验表明该负载型光催化电极具有很好的稳定性。