Developing methods for detection contaminants in drinking water is essential to ensuring that safe and acceptable quality drinking water is delivered to consumers. While manganese (Mn) was previously known only as a mere aesthetic issue, recent epidemiological data has shown to have negative neurological effects on humans, especially on children, prompting new health-based guidelines by Health Canada and the World Health Organization. In drinking water, Mn exists predominantly as Mn(II) and Mn(IV), and is regulated based on total Mn levels. Interestingly, measurement of Mn particulate using electroanalytical methods has not yet been reported in the literature. Herein, a digestion procedure for insoluble manganese dioxide (MnO₂) using ferrous (Fe²⁺) ions was optimized in preparation for Mn detection by cyclic voltammetry (CV). Digestion conditions including concentration of Fe²⁺ ions, pH and digestion time were explored and optimized. Digestion of MnO₂ was found to be successful in both perfect and imperfect stoichiometric ratios; however, digestion was shown to be most effective in perfect stoichiometric conditions. CV proved to be an effective technique for the detection of different particulate Mn concentrations with good reproducibility using glassy carbon electrodes. According to the CV data, the detection limits of 0.3 mmol·L^-1 and 0.1 mmol·L^-1 for MnO₂ were determined after the digestion time of 4.5 h and 24 h, respectively. The digestion method, in addition to CV detection, was found to be impacted by the presences of Cu²⁺ and Fe³⁺ ions.This interference suggests that this method may offer value as a multi-plexed technique. The Mn reduction signal was found to be enhanced in the presence of Mn²⁺, indicating that this method has the potential to be used to detect soluble and insoluble Mn species simultaneously. These digestion and detection methods are simple and reproducible methods which introduce the opportunity for total Mn detection in drinking water.

Magnesium alloys are promising candidates for bio-implant applications due to their biodegradability and biocompatibility. However, their rapid corrosion remains a critical limitation. This study presents the development of a multifunctional nanocomposite coating designed to enhance the corrosion resistance and antibacterial properties of magnesium alloy implants. The coating comprised γ-cyclodextrin metal-organic frameworks (γ-CD MOFs) decorated with TiO₂@Ag core-shell nanoparticles, embedded in a polycaprolactone (PCL) matrix. Immersion tests in a simulated body fluid (SBF) revealed an initially higher corrosion rate for the PCL-TiO₂@Ag/γ-CD MOF coating compared to the coating without TiO₂@Ag nanoparticles; however, it demonstrated significant improvement over time. After five days, the corrosion inhibition reached 95.44%, with the corrosion rate decreasing to 1.70 mpy. Additionally, the composite coating exhibited strong antibacterial activity against Escherichia coli, Pseudomonas, and Staphylococcus aureus. Furthermore, MTT assays indicated that the coating facilitated the growth and proliferation of osteoblast-like MC3T3-E1 cells, confirming its nontoxicity and biocompatibility. These findings highlight the potential of the PCL-TiO₂@Ag/γ-CD MOF nanocomposite as a biocompatible, antibacterial, and corrosion-resistant coating for biodegradable magnesium implants, offering a promising solution for biomedical applications.

Lithium metal anodes, with a theoretical capacity of up to 3860 mAh·g⁻¹, are regarded as the cornerstone for developing next-generation high-energy-density batteries. However, several key challenges hinder their practical applications, including dendrite formation, unstable solid electrolyte interphase (SEI), side reactions with electrolytes, and associated safety risks. This review systematically explores the mechanisms of lithium nucleation, growth, and stripping in both liquid and solid-state battery systems, analyzing critical theoretical concepts like heterogeneous nucleation thermodynamics, surface diffusion kinetics, space charge effects, and SEI-induced nucleation, which are crucial for understanding the genesis of dendrite growth. Additionally, the review discusses the electrochemical-mechanical coupling failures that lead to SEI degradation and the formation of dead lithium. For liquid systems, the review proposes strategies to mitigate dendrite formation and SEI instability, which include electrolyte optimization, artificial SEI design, and electrode framework design. In solid-state batteries, the review offers a granular analysis of the interface challenges associated with polymer, sulfide, and halide electrolytes and summarizes different solutions for different solid-state electrolytes. Meanwhile, the review emphasizes the importance of advanced characterization techniques and computational modeling in understanding and regulating the interface between lithium metal and electrolytes. Looking ahead, the review highlights future research directions that emphasize the integration of cross-disciplinary approaches to tackle these interconnected challenges. By addressing these issues, the path will be clear for the rapid commercialization and widespread application of lithium metal batteries, bringing us closer to realizing stable, high-energy-density batteries that can satisfy the escalating demands of modern energy storage applications across various industries.