Free-Standing N-Doped Porous Carbon Fiber Membrane Derived From Zn-MOF-74: Synthesis and Application as Anode for Sodium-Ion Battery With an Excellent Performance

Precise Tuning of Hollow and Pore Size of Bimetallic MOFs Derivate to Construct High-Performance Nanoscale Materials for Supercapacitors and Sodium-Ion Batteries

Precise control of pore volume and size of carbon nanoscale materials is crucial for achieving high capacity and rate performances of charge/discharge. In this paper, starting from the unique mechanism of the role of In, Zn combination, and carboxyl functional groups in the formation of the lumen and pore size, the composition of InZn-MIL-68 is regulated to precisely tune the diameter and wall pore size of the hollow carbon tubes. The hollow carbon nanotubes (CNT) with high-capacity storage and fast exchange of Na+ ions and charges are prepared. The CNT possess ultra-high specific capacitance and ultra-long cycle life and also offer several times higher Na+ ion storage capacity and rate performance than the existing CNTs. Density functional theory calculations and tests reveal that these superior characteristics are attributed to the spacious hollow structure, which provides sufficient space for Na+ storage and the tube wall's distinctive porosity of tube wall as well as open ends for facilitating Na+ rapid desorption. It is believed that precise control of sub-nanopore volume and pore size by tuning the composition of the carbon materials derived from bimetallic metal-organic frameworks (MOFs) will establish the basis for the future development of high-energy density and high-power density supercapacitors and batteries.

Sulfur functionalized biocarbon sorbents for low-concentration mercury isolation

Sulfur functionalized biocarbons were prepared from naturally abundant lignin alkali with sodium thiocyanate as an activation agent and a sulfur source. The resultant biocarbon sorbents showed a high mercury isolation ability from aqueous solutions, where high surface area and doping of sulfur significantly aid the uptake of mercury, i.e., 0.05 g of biocarbon sorbent removed 99% of mercury from 250 mL of simulated wastewater with an initial concentration of mercury of 10 mg L-1.

In Situ Construction of Nitrogen-Doped and Zinc-Confined Microporous Carbon Enabling Efficient Na+-Storage Abilities

Benefiting from the additional active sites for sodium-ion (Na⁺) adsorption and porous architecture for electrolyte accessibility, nitrogen-doped porous carbon has been considered the alternative anode material for Na⁺-storage applications. In this study, nitrogen-doped and zinc-confined microporous carbon (N,Z-MPC) powders are successfully prepared by thermally pyrolyzing the polyhedral ZIF-8 nanoparticles under an argon atmosphere. Following the electrochemical measurements, the N,Z-MPC not only delivers good reversible capacity (423 mAh/g at 0.02 A/g) and comparable rate capability (104 mAh/g at 1.0 A/g) but also achieves a remarkable cyclability (capacity retention: 96.6% after 3000 cycles at 1.0 A/g). Those can be attributed to its intrinsic characteristics: (a) 67% of the disordered structure, (b) 0.38 nm of interplanar distance, (c) a great proportion of sp²-type carbon, (d) abundant microporosity, (e) 16.1% of nitrogen doping, and (f) existence of sodiophilic Zn species, synergistically enhancing the electrochemical performances. Accordingly, the findings observed here support the N,Z-MPC to be a potential anode material enabling exceptional Na⁺-storage abilities.

Nanomaterials as carriers to improve the photodynamic antibacterial therapy

The main treatment for bacterial infections is antibiotic therapy, but the emergence of bacterial resistance has severely limited the efficacy of antibiotics. Therefore, another effective means of treating bacterial infections is needed to alleviate the therapeutic pressure caused by antibiotic resistance. Photodynamic antibacterial therapy (PDAT) has gradually entered people's field of vision as an infection treatment method that does not depend on antibiotics. PDAT induces photosensitizers (PS) to produce reactive oxygen species (ROS) under light irradiation, and kills bacteria by destroying biological macromolecules at bacterial infection sites. In recent years, researchers have found that some nanomaterials delivering PS can improve PDAT through targeted delivery or synergistic therapeutic effect. Therefore, in this article, we will review the recent applications of several nanomaterials in PDAT, including metal nanoclusters, metal-organic frameworks, and other organic/inorganic nanoparticles, and discuss the advantages and disadvantage of these nanomaterials as carriers for delivery PS to further advance the development of PDAT.

Electrospun Ta-MOF/PEBA Nanohybrids and Their CH4 Adsorption Application

For the first time, biocompatible and biodegradable Ta-metal organic framework (MOF)/polyether block amide (PEBA) fibrous polymeric nanostructures were synthesized by ultrasonic and electrospinning routes in this study. The XRD peaks of products were wider, which is due to the significant effect of the ultrasonic and electrospinning methods on the final product. The adsorption/desorption behavior of the nanostructures is similar to that of the third type of isotherm series, which showed mesoporous behavior for the products. The sample has uniform morphology without any evidence of agglomeration. Since the adsorption and trapping of gaseous pollutants are very important, the application of the final Ta-MOF/PEBA fibrous polymeric nanostructures was investigated for CH4 adsorption. In order to achieve the optimal conditions of experiments and also systematic studies of the parameters, fractional factorial design was used. The results showed that by selecting temperature 40°C, time duration 35 min, and pressure 3 bar, the CH4 gas adsorption rate was near 4 mmol/g. Ultrasonic and electrospinning routes as well as immobilization of Ta-MOF in the PEBA fibrous network affect the performance of the final products for CH4 gas adsorption.