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A novel bimetallic Ni/Co-based metal-organic framework (Ni/Co-MOF) was successfully synthesized via a simple solvothermal method, and used as electrode material for high performance supercapacitors. After doping of Co element, the Ni/Co-MOF materials retain the original crystalline topology structure of Ni3(BTC)2·12H2O. The as-obtained Ni/Co-MOF demonstrates an excellent specific capacitance of 1067 and 780 F/g at current density of 1 and 10 A/g, respectively, and can also retain 68.4% of the original capacitance after 2500 cycles. These results suggest that bimetallic Ni/Co-based MOFs are promising materials for the next generation supercapacitance, owing to their excellent electrochemical performance. The synthetic procedure can be applied to synthesize other bimetallic MOFs and enhance their conductive property.

A novel composite, polydopamine-modified Mo2C/MoO2 nanoparticles (HD-Mo2C/MoO2), as anode electrocatalyst for microbial fuel cells (MFCs), is synthesized via carbon thermal reduction and following in situ polydopamine modification. The physical and electrochemical characterizations show that Mo2C/MoO2 nanoparticles can be well dispersed through polydopamine modification and the resulting HD-Mo2C/MoO2 exhibits excellent electrocatalytic activity compared with unmodified Mo2C/MoO2. The MFC using HD-Mo2C/MoO2 as anode electrocatalyst achieves a maximum output power density of 1.64 ± 0.09 W m−2, which is 39% higher than that using Mo2C/MoO2 (1.18 ± 0.08 W m−2) as anode electrocatalyst. This excellent performance is attributed to modification of PDA, HD-Mo2C/MoO2 shows better hydrophilicity and electrocatalytic activity toward the direct oxidation of bacterial metabolites than unmodified Mo2C/MoO2.

A novel bi-component composite of porous self-assembled micro-/nanostructured Ni0.1Mn0.9O1.45 microellipsoids as high-performance anode electrocatalyst for microbial fuel cells (MFCs) is successfully synthesized via a simple coprecipitation reaction in microemulsion and calcination method in air atmosphere. The morphology and structural characterization indicate that the as-fabricated Ni0.1Mn0.9O1.45 product is consist of Mn2O3 and NiMn2O4 (n(Mn2O3): n(NiMn2O4) = 0.35: 0.1) and has a porous microellipsoidal morphology. The microellipsoids are compose of numerous layered micro-/nanostructured blocks and the special porous microellipsoids structure of Ni0.1Mn0.9O1.45 offers a large specific surface area for bacteria adhesion. The porous Ni0.1Mn0.9O1.45 microellipsoids as anode electrocatalyst for MFCs exhibits excellent electrocatalytic activity to promote the extracellular electron transfer (EET) between the anode and bacteria, hence improves the performance of MFC. The MFC equipped with Ni0.1Mn0.9O1.45/CF anode achieves a maximum power density of 1.39 ± 0.02 W m−2, is significantly higher than that of commercial carbon felt anode. This work proposes a new method for the synthesis of high-performance and environmentally friendly anode electrocatalyst for MFCs.

The anode material is a crucial factor that significantly affects the cost and performance of microbial fuel cells (MFCs). In this study, a novel macroscale porous, biocompatible, highly conductive and low cost electrode, carbonized polydopamine-modified cotton textile (NC@CCT), is fabricated by using normal cheap waste cotton textiles as raw material via a simple in situ polymerization and carbonization treatment as anode of MFCs. The physical and chemical characterizations show that the macroscale porous and biocompatible NC@CCT electrode is coated by nitrogen-doped carbon nanoparticles and offers a large specific surface area (888.67 m 2 g −1 ) for bacterial cells growth, accordingly greatly increases the loading amount of bacterial cells and facilitates extracellular electron transfer (EET). As a result, the MFC equipped with the NC@CCT anode achieves a maximum power density of 931 ± 61 mW m −2 , which is 80.5% higher than that of commercial carbon felt (516 ± 27 mW m −2 ) anode. Moreover, making full use of the normal cheap waste cotton textiles can greatly reduce the cost of MFCs and the environmental pollution problem.

Terthiophene (3THP) is evaluated as an electrolyte additive for improving cyclic stability of lithium nickel manganese oxide (LiNi 0.5 Mn 1.5 O 4 ) cathode for high energy density lithium-ion batteries. Charge/discharge tests demonstrate that 3THP is effective for improving the cyclic stability of LiNi 0.5 Mn 1.5 O 4 . With applying only 0.25% 3THP in a standard (1 M LiPF 6 in EC and DMC, 1/2 in volume) electrolyte, the capacity retention of Li/LiNi 0.5 Mn 1.5 O 4 cell after 350 cycles at 1C (1C = 147 mA g −1 ) under 4.9 V was improved from 50% to 91%, which is among the best that have been reported in literatures although the content of 3THP is far lower than those achieved by applying other additives. The physical characterizations from scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction, indicate that a thin cathode film has been formed on LiNi 0.5 Mn 1.5 O 4 particles, which suppresses the decomposition of electrolyte and protects LiNi 0.5 Mn 1.5 O 4 from structural destruction.

Cobalt-modified molybdenum dioxide nanoparticles highly dispersed on nitrogen-doped carbon nanorods (Co–MoO2/NCND), are synthesized from anilinium trimolybdate dihydrate nanorods, for the performance improvement of microbial fuel cell based on a mixed bacterial culture. Electrochemical measurements demonstrate that the as-synthesized Co–MoO2/NCND exhibits excellent electrocatalytic activity for the charge transfer on anode, providing the cell with a maximum power density of 2.06 ± 0.05 W m−2, which is strikingly higher than the bare carbon felt anode (0.49 ± 0.04 W m−2). The excellent performance of Co–MoO2/NCND is ascribed to the increased electronic conductivity of carbon nanorods by N-doping, the high ability of MoO2 to enrich electroactive bacteria, as demonstrated by high-throughput sequencing, and the enhanced activity of MoO2 by Co-modifying toward redox reactions in electroactive bacteria. This report provides a new concept of anode electrocatalyst fabrications for the application of microbial fuel cells in electricity generation and wastewater treatment.

We report a novel anode electrocatalyst, iron carbide nanoparticles dispersed in porous graphitized carbon (Nano-Fe3C@PGC), which is synthesized by facile approach involving a direct pyrolysis of ferrous gluconate and a following removal of free iron, but provides microbial fuel cells with superior performances. The physical characterizations confirm the unique configuration of iron carbide nanoparticles with porous graphitized carbon. Electrochemical measurements demonstrate that the as-synthesized Nano-Fe3C@PGC exhibits an outstanding electrocatalytic activity toward the charge transfer between bacteria and anode. Equipped with Nano-Fe3C@PGC, the microbial fuel cells based on a mixed bacterium culture yields a power density of 1856 mW m−2. The resulting excellent performance is attributed to the large electrochemical active area and the high electronic conductivity that porous graphitized carbon provides and the enriched electrochemically active microorganisms and enhanced activity towards the redox reactions in microorganisms by Fe3C nanoparticles.

TiO2 nanocones (TiO2-NCs) are constructed into arrayed spherical shells through a liquid-phase deposition reaction with polymer template, to improve the performance of TiO2 as anode of lithium ion microbattery. The morphology and structure characterizations indicate that TiO2 grows into nanocones with exposed {001} facets and is self-assembled into mesoporous structure. Meanwhile, macroporous channels are formed among the arrayed shells. Electrochemical measurements demonstrate that the TiO2-NCs reveal excellent performance in terms of improved lithium storage property and rate capability. The improved performance can be ascribed to the channel structure for the convenience of ionic transportation and the high-energy facets for the improvement of ionic reactivity.

A composite, polyaniline (PANI)/mesoporous tungsten trioxide (m-WO(3)), was developed as a platinum-free and biocompatible anodic electrocatalyst of microbial fuel cells (MFCs). The m-WO(3) was synthesized by a replicating route and PANI was loaded on the m-WO(3) through the chemical oxidation of aniline. The composite was characterized by using X-ray diffraction, Fourier transform infrared spectrum, field emission scanning electron microscopy, and transmission electron microscopy. The activity of the composite as the anode electrocatalyst of MFC based on Escherichia coli (E. coli) was investigated with cyclic voltammetry, chronoamperometry, and cell discharge test. It is found that the composite exhibits a unique electrocatalytic activity. The maximum power density is 0.98 W m(-2) for MFC using the composite electrocatalyst, while only 0.76 W m(-2) and 0.48 W m(-2) for the MFC using individual m-WO(3) and PANI electrocatalyst, respectively. The improved electrocatalytic activity of the composite can be ascribed to the combination of m-WO(3) and PANI. The m-WO(3) has good biocompatibility and PANI has good electrical conductivity. Most importantly, the combination of m-WO(3) and PANI improves the electrochemical activity of PANI for proton insertion and de-insertion.

A composite of nickel and β-molybdenum carbide (Ni/β-Mo2C) was prepared from solution derived precursor and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and Brunauer-Emmett-Teller (BET). The activity of Ni/β-Mo2C as noble-metal-free anodic electrocatalyst of microbial fuel cell (MFC) based on Klebsiella pneumoniae (K. pneumoniae) was investigated by electrochemical measurements. The results from voltammetric measurements show that Ni/β-Mo2C has high electrocatalytic activity towards the oxidation of formate, lactate, ethanol, and 2,6-di-tert-butyl-p-benzoquinon (2,6-DTBBQ), which are the main metabolites of K. pneumoniae. The results from polarization curve measurement indicate that the MFC using Ni/β-Mo2C as anodic electrocatalyst delivers a higher power density than the MFC using β-Mo2C as anodic electrocatalyst. Ni/β-Mo2C provides the MFC based on K. pneumoniae with a novel noble-metal-free anodic electrocatalyst of high activity.