二硫化铁/石墨烯阳极:提升微生物燃料电池性能的新方案

正近期,哈尔滨工业大学刘绍琴课题组根据Geobacter产电微生物可以利用Fe~(3+)和S作为电子传递通路的特性,通过简便的水热反应合成了二硫化铁/石墨烯复合物(FeS_2/rGO)作为微生物燃料电池的阳极。该复合纳米结构不仅极大地改善了Geobacter产电微生物在电极表面的黏附能力,而且有利于Geobacter在群落中与其他细菌的竞争,实现了     

微生物燃料电池Fe-N掺杂炭黑阴极催化剂性能研究

炭黑是一种廉价且具有高导电性的氧还原催化剂, 可应用于微生物燃料电池(MFCs)的阴极。然而, 纯炭黑的催化性能较差, 不能满足实际应用需求。为了提高炭黑的催化性能, 以氯化铁(FeCl₃)和三聚氰胺作为Fe源和N源按一定比例与炭黑混合共炭化, 对炭黑进行改性处理。结果表明, 当Fe-N与炭黑的质量比例为2.6∶1时, MFCs的输出功率密度达到最高值, 为1395 mW/m², 比Pt/C催化剂(876 mW/m²)提高了59%。SEM观察到炭黑基体上形成了椭圆形或柱状晶体, XRD和XPS测试结果显示是在共炭化过程中生成的Fe₃C晶体, 引入了吡啶氮和石墨氮, 在催化剂表面形成更多的活性位点, 这是复合催化剂性能提升的关键因素。随着Fe-N比例的提高, 复合催化剂的导电性和比表面积逐渐下降, 从另一方面又限制了其性能的提升。综上所述, 氯化铁、三聚氰胺和炭黑共炭化制备的复合催化剂是一种具有良好性价比的MFCs阴极催化剂, 可在规模化应用中发挥更大作用。     

阳极微生物的固定方式对微生物燃料电池性能的影响

研究了一种将微生物包埋在导电水凝胶中制备成微生物燃料电池(microbial fuel cell,MFC)阳极的新方法,该方法可以增加阳极上微生物的数量,并使多数微生物处于分散状态以利于代谢的扩散。该方法构建的阳极用在MFC中,显示了良好的效果。其最高功率密度和工作电压分别为0.243 W/m~2和0.350 V,比使用传统阳极的MFC分别高出89.843%和16.667%;其内阻则为263.780Ω,比使用传统阳极的MFC低78.973%。     

高活性氮掺杂介孔二氧化钛的合成及性能研究

采用水热法, 以聚乙二醇(PEG)为模板, N,N-二甲基甲酰胺为氮源, 制备了氮掺杂的介孔二氧化钛。并用X射线粉末衍射(XRD)、傅立叶红外光谱(FTIR)、BET、透射电子显微镜(TEM)、紫外一可见漫反射谱(DRS)和X射线光电子能谱(XPS)等技术手段对制备样品进行了表征。结果表明: 所合成的样品具有锐钛矿结构,直径约20 nm, 并且具有一定的可见光活性。以甲基橙(MO)为光降解模型, 样品在可见光区表现出了较好的催化活性, 这取决于烷氧基和氮掺杂的协同效应。     

氧化钴/氮掺杂介孔碳球的制备及其电化学性能研究

使用N-乙酰-D-氨基葡萄糖作为碳源,F127作为软模板,乙酸钴作为钴源和催化剂,在水热和高温热解条件下制得了具有较大的比表面积与丰富的介孔尺寸的孔道结构、尺寸为200~500nm的氧化钴/氮掺杂复合介孔碳球。该复合介孔碳球用作电极材料进行电化学测试,在2A/g的电流密度下电容值达到248.75F/g,经过1 000次循环寿命测试后其比电容值还能保留93%,显示出较高的比电容值和较好的循环稳定性,有望在能源存储、催化、吸附等领域得到应用。     

微生物燃料电池阳极材料及结构研究现状

微生物燃料电池(Microbial Fuel Cell,MFC)阳极是细菌附着、电子传递、底物和产物传输的场所,是影响电池性能的关键因素之一。综述了应用于MFC中阳极材料,如不同结构碳材料的优劣、金属及金属氧化物的性能,也对阳极材料的表面改性方法进行了汇总。     

微生物燃料电池阳极材料研究现状与展望

微生物燃料电池(Microbial fuel cell,MFC)是一种新兴的生物电化学技术,电极材料是影响其产电性能的重要因素。阳极主要为微生物的粘附和电子转移提供场所,利用产电菌降解废水中的有机污染物,实现同步处理废水和回收能源。主要介绍了MFC阳极材料的研究进展,分析了其导电性、产电效率等性能的研究现状,并对其进行了总结和展望。     

可溶性淀粉/三维氮掺杂石墨烯电化学性能研究

采用Hummers法制备氧化石墨烯(GO),再以GO为前驱体,尿素为掺杂剂,通过绿色、经济、简便的水热法制备了氮掺杂石墨烯;采用水热法,以尿素为掺杂剂,并加入可溶性淀粉,制备了三维氮掺杂石墨烯。加入可溶性淀粉后形成的三维结构进一步提高了氮掺杂石墨烯的电化学性能。可溶性淀粉/三维氮掺杂石墨烯复合材料修饰的电极,表面电化学反应迅速,电子转移过程主要受扩散过程控制。在GO/可溶性淀粉(质量比)为2∶1时,制备的可溶性淀粉/三维氮掺杂石墨烯具备良好的电化学稳定性,且电子迁移速率优异。     

Interface engineering of plasmonic induced Fe/N/C-F catalyst with enhanced oxygen catalysis performance for fuel cells application

The low intrinsic activity of Fe/N/C oxygen catalysts restricts their commercial application in the fuel cells technique;herein,we demonstrated the interface en...     

Three-dimensional carbon nanotube-textile anode for high-performance microbial fuel cells

Microbial fuel cells (MFCs) harness the metabolism of microorganisms, converting chemical energy into electrical energy. Anode performance is an important factor limiting the power density of MFCs for practical application. Improving the anode design is thus important for enhancing the MFC performance, but only a little development has been reported. Here, we describe a biocompatible, highly conductive, two-scale porous anode fabricated from a carbon nanotube-textile (CNT-textile) composite for high-performance MFCs. The macroscale porous structure of the intertwined CNT-textile fibers creates an open 3D space for efficient substrate transport and internal colonization by a diverse microflora, resulting in a 10-fold-larger anolyte-biofilm-anode interfacial area than the projective surface area of the CNT-textile. The conformally coated microscale porous CNT layer displays strong interaction with the microbial biofilm, facilitating electron transfer from exoelectrogens to the CNT-textile anode. An MFC equipped with a CNT-textile anode has a 10-fold-lower charge-transfer resistance and achieves considerably better performance than one equipped with a traditional carbon cloth anode: the maximum current density is 157% higher, the maximum power density is 68% higher, and the energy recovery is 141% greater.     

三维立体介孔结构的海藻酸钠/氧化石墨烯复合气凝胶的制备及其对亚甲基蓝的吸附

为了有效去除废水中的染料,本论文以海藻酸钠（SA）和氧化石墨烯（GO）为原料,采用一步水热法制备海藻酸钠/氧化石墨烯（SA/GO）复合水凝胶,并通过冷冻干燥法得SA/GO复合气凝胶。利用FT-IR、XRD、SEM、TEM、N₂等温吸附-脱附、接触角来表征SA/GO复合气凝胶并研究其吸附性能。结果表明,SA/GO复合气凝胶是具有三维立体结构的多孔材料,BET比表面积约为580.54 m²·g^-1。讨论了SA/GO复合气凝胶对亚甲基蓝（MB）溶液吸附过程的影响因素,在碱性条件下,吸附效果最好,吸附率可达99.41%,吸附量可达248.53 mg·g^-1,并表现出优异的循环再生性。     

Architecture engineering of hierarchically porous chitosan/vacuum-stripped graphene scaffold as bioanode for high performance microbial fuel cell

The bioanode is the defining feature of microbial fuel cell (MFC) technology and often limits its performance. In the current work, we report the engineering of a novel hierarchically porous architecture as an efficient bioanode, consisting of biocompatible chitosan and vacuum-stripped graphene (CHI/VSG). With the hierarchical pores and unique VSG, an optimized bioanode delivered a remarkable maximum power density of 1530 mW m(-2) in a mediator-less MFC, 78 times higher than a carbon cloth anode.     

Preparation and characterization of an amine-modified graphene aerogel for enhanced carbon dioxide adsorption

Journal of Materials Science - A 3D porous graphene aerogel (GA) was prepared via one-step hydrothermal method and freeze-drying technology, in which organic amine reagents were used as...     

Highly compressible graphene/polypyrrole aerogel for superelastic pseudocapacitors

Highly compressible graphene aerogel are proposed as the promising electrode materials for compression-tolerant electrochemical capacitors. Herein, the polypyrrole (PPy) was introduced into the compressible graphene aerogel to further improve its specific capacitance and compression-tolerant ability. As-prepared graphene/PPy aerogel withstands 95% repeated compression cycling without any structure collapse. The gravimetric capacitance of the superelastic pseudocapacitors based on graphene/PPy aerogel electrodes reaches 335 F g^?1 and can retain 97% even under 95% compressive strain. And a volumetric capacitance of 108 F cm^?3 is achieved due to the significantly increased density of the electrodes under 95% strain. This value of the volumetric capacitance can be preserved by 85% after 3500 charge/discharge cycles with various compression conditions. This work will pave the way for advanced applications in the area of compressible energy-storage devices.     

Microbial reduction of graphene oxide and its application in microbial fuel cells and biophotovoltaics

Despite more than a decade of study, there are still significant obstacles to overcome before graphene can be successfully produced on a large scale for commercial use. Chemical oxidation of graphite to produce graphene oxide (GO), followed by a subsequent reduction process to synthesize reduced graphene oxide (rGO), is considered the most practical method for mass production. Microorganisms, which are abundant in nature and inexpensive, are one of the potential green reductants for rGO synthesis. However, there is no recent review discussing the reported microbial reduction of GO in detail. To address this, we present a comprehensive review on the reduction of GO by a range of microorganisms and compared their efficacies and reaction conditions. Also, presented were the mechanisms by which microorganisms reduce GO. We also reviewed the recent advancements in using microbially reduced GO as the anode and cathode material in the microbial fuel cell (MFC) and algal biophotovoltaics (BPV), as well as the challenges and future directions in microbial fuel cell research.     

A redox-stable efficient anode for solid-oxide fuel cells

Solid-oxide fuel cells (SOFCs) promise high efficiencies in a range of fuels. Unlike lower temperature variants, carbon monoxide is a fuel rather than a poison, and so hydrocarbon fuels can be used directly, through internal reforming or even direct oxidation. This provides a key entry strategy for fuel-cell technology into the current energy economy. Present development is mainly based on the yttria-stabilized zirconia (YSZ) electrolyte. The most commonly used anode materials are Ni/YSZ cermets, which display excellent catalytic properties for fuel oxidation and good current collection, but do exhibit disadvantages, such as low tolerance to sulphur and carbon deposition when using hydrocarbon fuels, and poor redox cycling causing volume instability. Here, we report a nickel-free SOFC anode, La0.75Sr0.25Cr0.5Mn0.5O3, with comparable electrochemical performance to Ni/YSZ cermets. The electrode polarization resistance approaches 0.2 Omega cm2 at 900 degrees C in 97% H2/3% H2O. Very good performance is achieved for methane oxidation without using excess steam. The anode is stable in both fuel and air conditions, and shows stable electrode performance in methane. Thus both redox stability and operation in low steam hydrocarbons have been demonstrated, overcoming two of the major limitations of the current generation of nickel zirconia cermet SOFC anodes.     

Enhanced microwave absorption performance of graphene/doped Li ferrite nanocomposites

In the present study, Microwave absorbing Li-Sr, Li-Co ferrite nanoparticles and RGO/Li-Sr, RGO/Li-Co ferrite nanocomposites containing Li ferrite and reduced graphene oxide (RGO) were synthesized to further improve the microwave absorption performance of Li ferrite nanoparticles (LiFe₅O₈). The Li-Sr and Li-Co nanoparticles were synthesized by thermal treatment method, the RGO/Li-Sr and RGO/Li-Co nanocomposites were obtained by a polymerization method and were characterized by different techniques. The electromagnetic wave absorption properties of the samples were evaluated by vector network analyzer (VNA) in the frequency range of 2–18 GHz. The magnetic and dielectric loss, impedance matching, and electromagnetic wave absorption of the samples are significantly improved through the addition of RGO. Experimental results revealed that the RGO/Li-Co nanocomposite considerably increased microwave absorption. The minimum reflection loss (RL) of RGO/Li-Co also was found to reach −46.80 dB at the thickness of 3 mm and the effective absorption bandwidth (≤-10 dB) amounted to 6.80 GHz (from 10.52 to 17.32 GHz), which was much higher in comparison with pure Li and Li-Co ferrites nanoparticles. Due to the synergistic effect between magnetic loss and dielectric loss and the good impedance matching, the RGO/Li-Co nanocomposite may be regarded as a new candidate for microwave absorbing materials characterized with a broad effective absorption bandwidth at thin thicknesses.