Background The Co-Ge-Ni ternary system is important for thermoelectric and electronic applications. This study determines the Co-Ge-Ni isothermal sections at 800°C and 600°C. Methods Alloys were prepared from pure constituent elements, equilibrated, and their equilibrium phases were identified. Furthermore, the interfacial reactions between CoGe and Ni at 600°C and 500°C were investigated. The reaction couples were prepared using an annealed CoGe substrate electroplated with Ni. Significant Findings No ternary compound is found. Two continuous solid-solution phases, (Co,Ni)₅Ge₃ and (α-Co,Ni), exist at both 800°C and 600°C. At 800°C, the stable phases along the Co-Ge side are (α-Co,Ni), ε-(Co), (Co,Ni)₅Ge₃, CoGe, CoGe₂, and (Ge), whereas those along the Ge-Ni side are liquid, NiGe, (Co,Ni)₅Ge₃, Ni₃Ge, and (α-Co,Ni). At 600°C, there is no liquid phase, and Co₅Ge₂ and Co₅Ge₇ are stable. The Ni₃Ge phase exhibits significant Co solubility but does not form a continuous solid solution extending to the Co-Ge side. The reaction path of the Ni/CoGe diffusion couples is Ni/Ni₃Ge/(Co,Ni)₅Ge₃/CoGe, and Ge is the dominant diffusion species. The reaction layer thickness is 163 μm at 600°C for 7 days, 56 μm at 500°C for 7 days, and only 1 μm at 300°C for 50 days.
Background Mesotrione (MTE), a triketone herbicide widely applied for post-emergence weed control, poses concerns due to its persistence and potential residue accumulation in edible products. These risks necessitate rapid, sensitive, and reliable analytical strategies for food safety monitoring. Methods An efficient electrochemical sensor was developed using a functionalized carbon black-supported nickel manganese molybdate nanocomposite (NiMnMO4/f-CB) modified glassy carbon electrode (NMM/f-CB/GCE). The synergistic integration of ternary NMM with conductive f-CB provided abundant active sites, accelerated charge transport, and enhanced electrocatalytic activity toward MTE reduction. Structural and surface characterization confirmed the effective fabrication and homogeneous distribution of the composite on the electrode surface. Findings Under optimized conditions, the sensor exhibited a wide linear response range (0.01–816 μM) with an ultralow detection limit of 1.2 nM, demonstrating excellent sensitivity for trace-level monitoring. The electrode showed consistent operational performance, reproducibility, and durable storage stability. It also displayed satisfactory selectivity in the presence of typical interfering substances. Real-sample analyses in tomato juice, corn kernels, and sugarcane juice yielded accurate recoveries, confirming the sensor’s practical applicability for food safety assurance.
Background Solvent selection is a decisive step in solution crystallization, yet current methods remain constrained by limited-scale solubility screening and focus primarily on solubility, with safety and environmental considerations deferred until after solubility-based preselection. Methods This work proposes an integrated computational solvent screening framework for solution crystallization that simultaneously considers solubility and environmental–health–safety (EHS) indices. Aspirin crystallization is used as a case study to demonstrate the applicability of the framework. A large-scale preliminary screening of more than 8000 organic solvents is first conducted using predicted EHS indicators. Subsequently, the solubilities of the candidates satisfying the predefined EHS criteria are calculated by solving the solid–liquid equilibrium (SLE) and are used to estimate the theoretical crystallization yield and solvent equivalent mass. Candidates meeting the predefined crystallization-performance criteria are further assessed using experimentally reported EHS properties and practical considerations. Methyl 3-methoxypropionate (MMP) is subsequently selected as a representative solvent for experimental validation. Significant Findings The proposed framework provides a practical workflow for crystallization solvent selection by integrating large-scale EHS screening, solubility evaluation, and post-screening practical assessment. The aspirin case study supports its utility by identifying and validating MMP as a promising solvent candidate with a balanced crystallization-performance and process-safety profile.
Background Electrochemical nitrate reduction is a promising approach for mitigating nitrogen pollution in water. However, the development of electrocatalysts that simultaneously achieve high activity, N₂ selectivity, and operational stability remains a major challenge. Methods A two-dimensional (2D) Nb₂C MXene-modified copper mesh electrode (Nb₂C/Cu) was fabricated via a simple coating method. The morphology, structure, and surface properties of the composite were characterized using FESEM-EDS, HR-TEM, XRD, BET, and XPS, whereas LSV and EIS were employed to probe its electrochemical characteristics. The electrochemical nitrate reduction performance was systematically evaluated in a dual-chamber electrolytic cell under various operating conditions. Significant findings The optimized Nb₂C/Cu electrode achieved 93 % nitrate conversion, 92 % N₂ selectivity, a Faradaic efficiency of 81.35 %, and a low energy consumption of 0.067 kWh/g-N. The electrode maintained good performance over five consecutive reuse cycles while suppressing the formation of NO₂⁻ and NH₄⁺ by-products. Electrochemical analyses revealed that the Nb₂C/Cu interface enhances electron transfer and reduces charge-transfer resistance, thereby suppressing the competing hydrogen evolution reaction and promoting selective nitrate-to-nitrogen conversion.
