Effect of Solvothermal Temperature on Morphology and Supercapacitor Performance of Ni-MOF

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.

Synthesis and applications of luminescent metal organic frameworks (MOFs) for sensing dipicolinic acid in biological and water samples: a review

The detection of trace quantities of 2,6-dipicolinic acid (DPA) in real-world samples is crucial for early disease diagnosis and routine health monitoring. Metal-organic frameworks (MOFs), recognized for their diverse structural architectures, have emerged as advanced multifunctional hybrid materials. One of the most notable properties of MOFs is their luminescence (L), which can arise from structural ligands, guest molecules, and emissive metal ions. Luminescent MOFs have shown significant promise as platforms for sensor design. This review highlights the application of luminescent MOFs in the detection of DPA in biological and aqueous environments. It provides a comprehensive discussion of the various detection strategies employed in luminescent MOF-based DPA sensors. Additionally, it explores the origins of L in MOFs, their synthesis, and the mechanisms underlying their sensing capabilities. The article also addresses key challenges and limitations in this field, offering practical insights for the development of efficient luminescent MOFs for DPA detection.

Transforming cancer detection and treatment with nanoflowers

Nanoflowers, an innovative class of nanoparticles with a distinctive flower-like structure, have garnered significant interest for their straightforward synthesis, remarkable stability, and heightened efficiency. Nanoflowers demonstrate versatile applications, serving as highly sensitive biosensors for rapidly and accurately detecting conditions such as diabetes, Parkinson's, Alzheimer's, and foodborne infections. Nanoflowers, with their intricate structure, show significant potential for targeted drug delivery and site-specific action, while also exhibiting versatility in applications such as enzyme purification, water purification from dyes and heavy metals, and gas sensing through materials like nickel oxide. This review also addresses the structural characteristics, surface modification, and operational mechanisms of nanoflowers. The nanoflowers play a crucial role in preventing premature drug leakage from nanocarriers. Additionally, the nanoflowers contribute to averting systemic toxicity and suboptimal therapy efficiency caused by hypoxia in the tumor microenvironment during chemotherapy and photodynamic therapy. This review entails the role of nanoflowers in cancer diagnosis and treatment. In the imminent future, the nanoflowers system is poised to revolutionize as a smart material, leveraging its exceptional surface-to-volume ratio to significantly augment adsorption efficiency across its intricate petals. This review delves into the merits and drawbacks of nanoflowers, exploring synthesis techniques, types, and their evolving applications in cancer.

Hybridization of metal-organic frameworks and MXenes: Expanding horizons in supercapacitor applications

Metal-organic frameworks (MOFs) and MXenes have gained prominence in the queue of advanced material research. Both materials' outstanding physical and chemical characteristics prominently promote their utilization in diverse fields, especially the electrochemical energy storage (EES) domain. The collective contribution of extremely high specific surface area (SSA), customizable pores, and abundant active sites propose MOFs as integral materials for EES devices. However, conventional MOFs endure low conductivity, constraining their utility in practical applications. The development of hybrid materials via integrating MOFs with various conductive materials stands out as an effective approach to improvising MOF's conductivity. MXenes, formulated as two-dimensional (2D) carbides and nitrides of transition metals, fall in the category of the latest 2D materials. MXenes possess extensive structural diversity, impressive conductivity, and rich surface chemical characteristics. The electrochemical characteristics of MOF@MXene hybrids outperform MOFs and MXenes individually, credited to the synergistic effect of both components. Additionally, the MOF derivatives coupled with MXene, exhibiting unique morphologies, demonstrate outstanding electrochemical performance. The important attributes of MOF@MXene hybrids, including the various synthesis protocols, have been summarized in this review. This review delves into the architectural analysis of both MOFs and MXenes, along with their advanced hybrids. Furthermore, the comprehensive survey of the latest advancements in MOF@MXene hybrids as electroactive material for supercapacitors (SCs) is the prime objective of this review. The review concludes with an elaborate discussion of the current challenges faced and the future outlooks for optimizing MOF@MXene composites.

Effect of synthesis temperature on the structural morphology of a metal-organic framework and the capacitor performance of derived cobalt-nickel layered double hydroxides

Three-dimensional interconnected nickel-cobalt layered double hydroxides (NiCo-LDHs) were prepared on nickel foam by ion exchange using a cobalt-based metal-organic framework (Co-MOF) as a template at different temperatures. The effects of the Co-MOF preparation temperature on the growth, mass, morphology, and electrochemical properties of the Co-MOF and derived NiCo-LDH samples were studied. The synthesis temperature from 30 to 50 °C gradually increased the mass of the active material and the thickness of the Co-MOF sheets grown on the nickel foam. The higher the temperature is, the larger the proportion of Co3+. β-Cobalt hydroxide (β-Co(OH)2) sheets were generated above 60 °C. The morphology and mass loading pattern of the derived flocculent layer clusters of NiCo-LDH were inherited from metal-organic frameworks (MOFs). The areal capacitance of NiCo-LDH shows an inverted U-shaped curve trend with increasing temperature. The electrode material synthesized at 50 °C had a tremendous specific capacitance of 7631 mF·cm-2 at a current density of 2 mA·cm-2. The asymmetric supercapacitor assembled with the sample and active carbon (AC) achieved an energy density of 55.0 Wh·kg-1 at a power density of 800.0 W·kg-1, demonstrating the great potential of the NiCo-LDH material for energy storage. This work presents a new strategy for designing and fabricating advanced green supercapacitor materials with large power and energy densities.

Bimetallic PCN-333 with Modulated Crystallization and a Porosity Structure for a Highly Efficient Removal of Congo Red

Bimetallic metal-organic frameworks (BMOFs) have garnered significant attention in the field of environmental remediation due to their more diverse adsorption sites compared to monometallic metal-organic frameworks (MOFs). Different energy barriers must be overcome for different metal ions and organic linkers to form MOFs. However, the impact of the synthesis temperature on the crystallization and porosity structure of BMOFs has been rarely studied. In this work, PCN-333 series-based BMOFs with different Fe/Al ratios were prepared by a solvothermal method at temperatures of both 135 and 150 °C. The synthesis temperature and Fe/Al ratio have significant effects on the crystal structure and specific surface area of bimetallic PCN-333, leading to the different adsorption performance of the PCN-333 for Congo red (CR). The Fe/Al-PCN-333-135(3:1) and Fe-PCN-333-150 exhibited the maximum CR adsorption capacities of 3233 and 3933 mg/g, respectively, surpassing the capacities of most previously documented adsorbents. The Langmuir model and pseudo-second-order kinetics can well describe the adsorption process of CR on Fe/Al-PCN-333-135(3:1) and Fe-PCN-333-150. Combining the isotherm adsorption behavior with the thermodynamic parameters, CR adsorption on BMOFs is a single-layer endothermic chemical adsorption. Furthermore, Fe/Al-PCN-333-135(3:1) and Fe-PCN-333-150 exhibited regenerability and reusability for three cycles with reasonable efficiency. This work is of great significance in the field of engineering BMOF materials to treat dye wastewater.

Mixed solvent-assisted synthesis of high mass loading amorphous NiCo-MOF as a promising electrode material for supercapacitors

The pursuit of high mass loading metal-organic framework (MOF) materials via a simple method is crucial to achieve high-performance supercapacitors. Herein, an amorphous NiCo-MOF material with a high mass loading of up to 10.3 mg cm-2 was successfully prepared using a mixed solvent system of ethanol and water. In addition, by adjusting the volume ratio of ethanol to water, amorphous NiCo-MOFs with three different morphologies including nanospheres, nanopores, and ultra-thick plates were obtained. It was found that the different solvent systems not only affected the growth rate of MOFs, but also controlled their nucleation rate by changing the coordination environment of the metal ions, and thus achieved morphology and mass loading regulation, thereby influencing their energy storage behavior. Notably, the optimum NiCo-MOF exhibited the superior specific capacitance of up to 9.7 F cm-2 (941.8 F g-1) at a current density of 5 mA cm-2 and high-rate capability of 71.1% even at 20 mA cm-2. Moreover, the corresponding assembled solid-state supercapacitor exhibited an excellent energy density of 0.65 mW h cm-2 at a power density of 2 mW cm-2 and capacity retention of 84.7% after 8000 cycles at 30 mA cm-2. Overall, this work proposes a feasible and effective strategy to achieve high mass loading NiCo-MOFs, impacting their ultimate electrochemical performance, which can possibly be further extended to other MOFs with superior capacitance.

NiCo-MOF Nanospheres Created by the Ultra-Fast Microwave Method for Use in High-Performance Supercapacitors

Metal-organic frameworks-through the use of creative synthetic designs-could produce MOF materials with excellent porosity, stability, particle microstructures, and conductivity, and their inherent characteristics-including their porosity and controllable structure-may result in an immense number of prospects for energy storage. In this paper, a nanosphere-like NiCo-MOF was effectively manufactured via an ultra-fast microwave technique. Additionally, the ideal synthesis conditions of the NiCo-MOF were investigated by adjusting the microwave output power and microwave reaction time. Under the reaction conditions of a 600 W microwave and a 210 s microwave reaction time, the NiCo-MOF exhibited an excellent capacitance of 1348 F/g at a current density of 1 A/g and an 86.1% capacity retention rate at 10 A/g. In addition, self-assembled NiCo-MOF/AC asymmetric capacitors showed a splendid energy density of 46.6 Wh/kg and a power density of 8000 W/kg.