Ti3C2Tx nanosheet@Cu/Fe-MOF separators for high-performance lithium-sulfur batteries: an experimental and density functional theory study.

Lithium-sulfur (Li-S) batteries have attracted much attention due to their superior theoretical specific capacity and high theoretical energy density. However, rapid capacity fading originating from the shuttle effect, insulating the S cathode and the dendrite formation on the Li anode restrict the practical applications of Li-S batteries. Herein, we suggest novel coatings on glass fiber separators to satisfy all high-performance Li-S battery requirements. A conductive Ti3C2Tx (MXene) nanosheet/Fe-MOF or Ti3C2Tx (MXene) nanosheet/Cu-MOF layer was coated on a glass fiber separator to act as a polysulfide trapping layer. The MXene layer with high conductivity and polar surface functional groups could confine polysulfides and accelerate the redox conversions. The porous MOF layer acts as a Li ion sieve, thereby leading to the interception of polysulfides and mitigation of Li dendrite growth. The cells with the Cu-MOF/MXenes and Fe-MOF/MXene separators display superior capacities of 1100 and 1131 mA h g-1 after 300 cycles, respectively, whereas the cell with a pure glass fiber separator delivers a very low capacity of 309 mA h g-1 after 300 cycles. With Fe-MOF/MXene and Cu-MOF/MXene configurations, the discharge capacity, coulombic efficiency, cycling stability, and electrochemical conversion reactions are significantly improved. Our ab initio calculations demonstrate that the MXene layer dissociates lithium polysulfides into adsorbed S and mobile Li ions, which explains the experimental findings.

Understanding the endocrine disruptor and determination of bisphenol A by functional Cu-BTABB-MOF/rGO composite as facile rapid electrochemical sensor: an experimental and DFT investigation.

A pioneering CuBTABB-MOF/rGO composite customized electrode is fabricated and utilized as a sensor towards identifying bisphenol A (BPA) in a phosphate buffer solution of pH 7.0. The composite is characterized by FTIR, Raman spectroscopy, XRD, SEM, EDX, HRTEM, and XPS to study its structural and morphological properties. Compared with Cu-BTABB-MOF and Cu-BTABB-MOF@GO, the Cu-BTABB-MOF@rGO modified electrode is more sensitive and selective to BPA due to a strong interaction between them. The developed Cu-BTABB-MOF@rGO modified electrode exhibits good sensitivity (6.95 × 10-5 A mol-1 L-1) for BPA having a wide linear range of 0-100 µmol L-1 with the LOD of 2.08 × 10-5 mol L-1, reproducibility of 4.35%, and relative standard deviation (RSD) and stability of 90% for thirty days. In addition, the developed electrocatalyst remained unoccupied from interfering substances and consequently provided an encouraging platform for swift detection of BPA in real samples such as pond water and packed water bottles. Additionally, we utilized DFT (density functional theory) to model GO and Cu-BTABB-MOF structures for detecting BPA molecules.

Review on recent progress in metal-organic framework-based materials for fabricating electrochemical glucose sensors.

Diabetes is a type of disease that threatens human health, which can be diagnosed based on the level of glucose in the blood. Recently, various MOF-based materials have been developed as efficient electrochemical glucose sensors because of their tunable pore channels, large specific surface area well dispersed metallic active sites, etc. In this review, the significance of glucose detection and the advantages of MOF-based materials for this application are primarily discussed. Then, the application of MOF-based materials can be categorized into two types of glucose sensors: enzymatic biosensors and non-enzymatic sensors. Finally, insights into the current research challenges and future breakthrough possibilities regarding electrochemical glucose sensors are considered.

Improved performance of lithium-sulfur batteries by employing a sulfonated carbon nanoparticle-modified glass fiber separator.

Some of the most promising alternatives in the energy storage sector are lithium-sulfur batteries, which have a high energy density and theoretical capacity. However, the low electrical conductivity of sulfur and the shuttle effect of polysulfides remain important technical obstacles in the practical use of lithium-sulfur batteries (LSBs). This work employed a glass fiber separator with sulfonated carbon nanoparticles (SCNPs) to reduce the shuttle effect. The negatively charged sulfonic groups in SCNPs might prevent polysulfide migration and anchor lithium polysulfides. By using carbon-based interlayers, this method improves ion conductivity. Furthermore, the equally scattered sulfonic groups serve as active sites, causing sulfur to be distributed consistently and limiting sulfur growth while enhancing active sulfur utilization. After 200 cycles at 1C, the SCNP separator-containing cell showed a specific capacity of 1080 mA h g-1. After 200 cycles, the cell with a CNP separator only showed a specific capacity of 854 mA h g-1, demonstrating that CNPs' polysulfide diffusion suppression was ineffective. The cell with the SCNP separator still showed a high capacity of 901 mA h g-1 after 500 cycles, with an average coulombic efficiency of almost 98%.

Polycarboxylate Functionalized Graphene/S Composite Cathodes and Modified Cathode-Facing Side Coated Separators for Advanced Lithium-Sulfur Batteries.

Sulfur-hosting novel materials as a cathode for lithium-sulfur batteries are in the focus of many research to enhance the specific capacity and cycling stability. Herein, we developed composite cathodes consisting of polycarboxylate functionalized graphene (PC-FGF) doped with TiO2 nanoparticles or poly1,5-diaminoanthraquinone (PDAAQ) and sulfur to enhance chemisorption property toward polysulfides. Additionally, PC-FGF/sulfur composite cathode functions as an efficient trapping site for polysulfides spices as well as contributes to facilitate electron and Li-ions movement toward or from the cathode. In the first experiment, the cell with sulfur incorporated TiO2/PC-FGF cathode is assembled with three different cathode-facing side-coated glass fiber separators. At the second test, PDAAQ/PC-FGF cathode is assembled with the same separator materials as before.The best electrochemical performance observed was sulfur incorporated TiO2/PC-FGF cathode with PDAAQ/PC-FGF-coated separator having a high discharge capacity of 1100 mAh g- 1 at 0.5 C after 100 cycles. It is found that the combination of TiO2/PC-FGF/sulfur cathode and PDAAQ/PC-FCF separator could serve as promising cathode and separator material due to high cycling stability and rate capability for advanced Li-S batteries.