ZIF-8-derived Cu, N co-doped carbon as a bifunctional cathode catalyst for enhanced performance of microbial fuel cell

Static magnetic field-enhanced cathodic electrocatalysis of Fe3O4-based nitrogen-doped carbon for improving the performance of microbial fuel cells

Enhancing oxygen reduction reaction (ORR) electrocatalysis through an external static magnetic field to improve the performance of microbial fuel cells (MFCs) is technically feasible, but its application in MFCs remains largely unexplored. Herein, we present a Fe3O4-based nitrogen-doped carbon (Fe3O4@NC2) magnetic catalyst that significantly boosts ORR catalytic activity, increasing the half-wave potential (E1/2) of the ORR by approximately 20 mV with a magnetic field strength of 140 mT. When the Fe3O4@NC2 cathode is combined with an external magnetic field into the MFCs, the maximum power density of the MFC can reach 553.17 ± 7.16 mW m-2. This performance notably exceeds that of the same MFCs operated without a magnetic field (522.26 ± 4.25 m-2) and that of MFCs equipped with a Pt/C cathode (447.29 ± 2.16 mW m-2). This study introduces an effective and straightforward cathodic magnetic enhancement approach, offering promising avenues for advancing MFCs technology.

Facilely Prepared Carbon Dots as Effective Anode Modifier for Enhanced Performance of Microbial Fuel Cells

Microbial fuel cells (MFCs) are a promising technology for obtaining energy in wastewater. Effective extracellular electron transfer is one of the key factors for its practical application. In this work, carbon dots (CDs) enriched with oxygen-containing groups on the surface were synthesized as an efficient anode modifier using a simple hydrothermal method and common reactants. The experimental findings indicated that anodes modified with CDs exhibited increased electrical conductivity and greater hydrophilicity. These modifications facilitated increased microorganism loading and contributed to enhancing electrochemical processes within the anode biofilm. The CD-modified MFCs exhibited higher maximum power density (661.1 ± 42.6 mW·m-2) and open-circuit voltage (534.50 ± 6.4 mV), which were significantly better than those of the blank group MFCs (484.1 ± 14.1 mW·m-2 and 447.50 ± 12.1 mV). The use of simple carbon materials to improve the microbial loading on the MFCs anode and the electron transfer between the microbial-electrode may provide a new idea for the design of efficient MFCs.

Bamboo-like nitrogen-doped carbon supported chlorine-doped Fe2P as an antibacterial oxygen reduction catalyst

Bio-inspiration and biomimetics offer guidance for designing and synthesizing advanced catalysts for the oxygen reduction reaction (ORR) in microbial fuel cells (MFCs). Herein, a chlorine-doped Fe2P supported by nitrogen-doped carbon (Cl-Fe2P/NC) catalyst was designed and prepared based on imitating the bamboo structure. The electronegative chlorine captured the electron transfer from Fe2P and transferred it to NC through carbon nanotubes (CNTs). The antibacterial chlorine inhibited the cathode biofilm formation to enhance the ion transport. Cl-Fe2P/NC achieved a half-wave potential of 0.91 V and an onset potential of 0.99 V versus a reversible hydrogen electrode. After 500 h of reaction, the MFCs assembled by the Cl-Fe2P/NC cathode achieved a maximum power density of 1505 mW m-2. This work provides insights into the design of advanced materials through bio-inspiration and biomimicry.

Unveiling the potential of HKUST-1: synthesis, activation, advantages and biomedical applications

Metal-organic frameworks (MOFs) have emerged as a unique class of nanostructured materials, resulting from the self-assembly of metal ions or clusters with organic ligands, offering a wide range of applications in fields such as drug delivery, gas catalysis, and electrochemical sensing. Among them, HKUST-1, a copper-based MOF, has gained substantial attention due to its remarkable three-dimensional porous structure. Comprising copper ions and benzene-1,3,5-tricarboxylic acid, HKUST-1 exhibits an extraordinary specific surface area and pronounced porosity, making it a promising candidate in biomedicine. Notably, the incorporation of copper ions endows HKUST-1 with noteworthy activities, including antitumor, antibacterial, and wound healing-promoting properties. In this comprehensive review, we delve into the various synthesis methods and activation pathways employed in the preparation of HKUST-1. We also explore the distinct advantages of HKUST-1 in terms of its structural properties and functionalities. Furthermore, we investigate the exciting and rapidly evolving biomedical applications of HKUST-1. From its role in tumor treatment to its antibacterial effects and its ability to promote wound healing, we showcase the multifaceted potential of HKUST-1 in addressing critical challenges in biomedicine.

Nanoarchitectonics of heteroatom-doped hierarchical porous carbon derived from carboxymethyl cellulose carbon aerogel and metal-organic framework for capacitive deionization

Capacitive deionization (CDI) using porous materials offers a sustainable solution for providing affordable freshwater, but the low salt adsorption rate of benchmark carbon materials significantly limit the practical implementation. Herein, we utilized carboxymethyl cellulose sodium (CMC) as the carbon skeleton to produce a composite carbon aerogel loaded with ZIF-8 (ZIF-8/CMC-CA). The presence of ZIF-8 nanoparticles improved the pore structure of the material and provides a certain pseudo capacitance by introducing N. Compared with ZIF-8 derived carbons (ZIF-8-C), the CMC provided a good three-dimensional structure for the dispersion of ZIF-8 nanoparticles, reduced the agglomeration of particles. Furthermore, numerous carboxyl and hydroxyl groups on CMC enhanced the hydrophilicity of materials. Due to the interconnected structure, ZIF-8/CMC-CA exhibited excellent conductivity, a high specific surface area, and offered suitable channels for the rapid entry and exit of ions. In a three-electrode system, the total specific capacitance of the ZIF-8/CMC-CA electrode was 357.14 F g^-1. The adsorption rate of ZIF-8/CMC-CA was 2.02 mg g^-1 min^-1 in a 500 mg L^-1 NaCl solution. This study may provide new insight for modifying and fabricating electrode materials for practical CDI applications.