Improving oxygen reduction reaction by cobalt iron-layered double hydroxide layer on nickel-metal organic framework as cathode catalyst in microbial fuel cell

Advanced Alkali Metal Batteries Based on MOFs and Their Composites

The integration of metal-organic frameworks (MOFs) with functional materials has established a versatile platform for a wide range of energy storage applications. Due to their large specific surface area, high porosity, and tunable structural properties, MOFs hold significant promise as components in energy storage systems, including electrodes, electrolytes, and separators for alkali metal-ion batteries (AIBs). Although lithium-ion batteries (LIBs) are widely used, their commercial graphite anode materials are nearing their theoretical capacity limits, and the scarcity of lithium and cobalt resources increases costs. Although zinc-ion batteries (ZIBs) suffer from limited cycling stability, they are attractive for their low cost, high capacity, and excellent safety. Meanwhile, potassium-ion (PIBs) and sodium-ion batteries (SIBs) show promise due to their affordability and abundant resources, but they encounter issues such as short cycle life and low energy density. This review outlines the applications of MOF composites in LIBs, SIBs, and ZIBs, introduces common synthesis methods, and forecasts future development directions and challenges in energy storage applications. We emphasize how the understanding can lay the foundation for developing MOF composites with enhanced functionalities.

One-step annealing in situ synthesis of low tortuosity corn straw cellulose biochar/Fe3C: Application for cathode catalyst in microbial fuel cell

Synthesis of microbial fuel cell (MFC) cathode catalysts using corn straw with natural multi-channel structure is an useful measure for developing sustainable energy sources and making creative use of agricultural waste. The catalytic performance of nanomaterial catalysts in the oxygen reduction reaction (ORR) is clearly influenced by porosity and channel structure. Mesopores usually contribute to the enhancement of reaction kinetics and mass transfer. Therefore, in this paper, we have devised a method for the in situ synthesis of Fe3C/B (CIP) using cold isostatic pressure (CIP), which is inspired by the natural channel structures in plants that conduct water, salt and organic matter. The low tortuosity in materials due to this special structure can make it easier to create continuous electron channels and direct ion transfer channels. In addition, Fe3C/B (CIP) has amorphous characteristic defects (ID/IG = 0.82), high specific surface area (817.04 m2g-1), and mesoporous structure (3.240 nm). When Fe3C/B (CIP) was used as the cathode catalyst, the maximum power density of the MFC (1370.31 mW/m2) was 44.79 % higher than that of the commercial Pt/C catalyst (946.40 mW/m2). The present study offers an MFC cathode catalyst with a long cycling stability and high power density.

Power Production and Degradation of Pesticide Wastewater Through Microbial Fuel Cells with the Modified Activated Carbon Air Cathode by Hollow-Carbon and Carbon-Encapsulated Structures

Microbial fuel cell (MFC) can degrade pesticide wastewater and recovery energy simultaneously, and the activated carbon (AC) air cathode has great prospects for practical application. However, insufficient active sites and the limitation of multi-step electron transfer for oxygen reduction reaction (ORR) requires that AC should be modified by highly efficient electrocatalysts. Herein, busing the confinement effect of carbon-encapsulated metal and hollow carbon, we designed a unique ORR catalyst of Fe-Fe3O4-NC through utilizing the 2D leaf-like nanoplates of Zn-ZIF-L to load Prussian blue (PB) particles. The volatilization of low-boiled Zn and the catalysis of iron compounds led to the formation of confined walls of hollow carbon shell and carbon-encapsulated Fe/Fe3O4 particles on N-doped carbon substrate. Multivalent iron, a large surface area (368.11 m2·g-1), N doping, a heterojunction interface, and the confinement effect provided all the Fe-Fe3O4-NC-modified AC air cathodes with excellent ORR activity. The optimal samples of AC-Fe-Fe3O4-NC-3 achieved a peak power density of 1213.8 mW·m-2, demonstrating a substantial 82.8% increase over that of the bare AC. Furthermore, its efficiency in glyphosate removal reached 80.1%, surpassing the 23.2% of the bare AC. This study offers new ideas in constructing composite confined structures and the as-designed Fe-Fe3O4-NC is a promising modification candidate for the commercial adoption of AC air cathodes.

A review of microbial fuel cell and its diversification in the development of green energy technology

The advancement of microbial fuel cell technology is rapidly growing, with extensive research and well-established methodologies for enhancing structural performance. This terminology attracts researchers to compare the MFC devices on a technological basis. The architectural and scientific successes of MFCs are only possible with the knowledge of engineering and technical fields. This involves the structure of MFCs, using substrates and architectural backbones regarding electrode advancement, separators and system parameter measures. Knowing about the MFCs facilitates the systematic knowledge of engineering and scientific principles. The current situation of rapid urbanization and industrial growth is demanding the augmented engineering goods and production which results in unsolicited burden on traditional wastewater treatment plants. Consequently, posing health hazards and disturbing aquatic veracity due to partial and untreated wastewater. Therefore, it's sensible to evaluate the performance of MFCs as an unconventional treatment method over conventional one to treat the wastewater. However, MFCs some benefits like power generation, stumpy carbon emission and wastewater treatment are the main reasons behind the implementation. Nonetheless, few challenges like low power generation, scaling up are still the major areas needs to be focused so as to make MFCs sustainable one. We have focused on few archetypes which majorities have been laboratory scale in operations. To ensure the efficiency MFCs are needed to integrate and compatible with conventional wastewater treatment schemes. This review intended to explore the diversification in architecture of MFCs, exploration of MFCs ingredients and to provide the foreseen platform for the researchers in one source, so as to establish the channel for scaling up the technology. Further, the present review show that the MFC with different polymer membranes and cathode and anode modification presents significant role for potential commercial applications after change the system form prototype to pilot scale.

Improving bioelectrochemical performance by sulfur-doped titanium dioxide cooperated with Zirconium based metal-organic framework (S-TiO2@MOF-808) as cathode in microbial fuel cells

The sulfur-doped titanium dioxide (S-TiO2) cooperated with Zirconium based on a kind of metal-organic framework (MOF-808) was successfully prepared as cathode catalyst (S-TiO2@MOF-808) of microbial fuel cell (MFC) by two-step hydrothermal reaction. The particle size was approximately 5 μm, and the spherical S-TiO2 particle was attached to the surface of MOF-808 as irregular block solid. Zr-O, C-O and O-H bond were indicated to exist in S-TiO2@MOF-808. When n (Zr4+): n(Ti4+) was 1: 5, S-TiO2@MOF-808 showed better oxygen reduction reaction (ORR). The introduction of S-TiO2 restrained the framework collapse of MOF-808, S-TiO2@MOF-808 showed much higher catalytic stability in reaction. The recombination of sulfur and TiO2 reduced the charge transfer resistance, accelerated the electron transfer rate, and improved ORR greatly. The maximum power density of S-TiO2@MOF-808-MFC was 84.05 mW/m2, about 2.17 times of S-TiO2-MFC (38.64 mW/m2). The maximum voltage of S-TiO2@MOF-808-MFC was 205 mV, and the stability was maintained for 6 d.