Revealing the CO2 Conversion at Electrode/Electrolyte Interfaces in Li–CO2 Batteries via Nanoscale Visualization Methods

Lithium–carbon dioxide (Li–CO₂) battery technology presents a promising opportunity for carbon capture and energy storage. Despite tremendous efforts in Li–CO₂ batteries, the complex electrode/electrolyte/CO₂ triple-phase interfacial processes remain poorly understood, in particular at the nanoscale. Here, using in situ atomic force microscopy and laser confocal microscopy-differential interference contrast microscopy, we directly observed the CO₂ conversion processes in Li–CO₂ batteries at the nanoscale, and further revealed a laser-tuned reaction pathway based on the real-time observations. During discharge, a bi-component composite, Li₂CO₃/C, deposits as micron-sized clusters through a 3D progressive growth model, followed by a 3D decomposition pathway during the subsequent recharge. When the cell operates under laser (λ=405 nm) irradiation, densely packed Li₂CO₃/C flakes deposit rapidly during discharge. Upon the recharge, they predominantly decompose at the interfaces of the flake and electrode, detaching themselves from the electrode and causing irreversible capacity degradation. In situ Raman shows that the laser promotes the formation of poorly soluble intermediates, Li₂C₂O₄, which in turn affects growth/decomposition pathways of Li₂CO₃/C and the cell performance. Our findings provide mechanistic insights into interfacial evolution in Li–CO₂ batteries and the laser-tuned CO₂ conversion reactions, which can inspire strategies of monitoring and controlling the multistep and multiphase interfacial reactions in advanced electrochemical devices.     

Reversible Postsynthetic Modification in a Metal–Organic Framework

Postsynthetic modification (PSM) of metal–organic frameworks (MOFs) provides access to functional materials and advanced porous solid engineering. Herein, we report the reversible PSM of a multivariate isoreticular MOF by applying dynamic furan-maleimide Diels–Alder (DA) chemistry. The key step involves incorporating a furan group into the MOF via “click” PSM, which can then undergo repeated cycles of modification and de-modification with maleimides. The structural integrity, crystallinity, and porosity of the furan-appended MOF remained intact even after three consecutive PSM/de-modification cycles using three different functionalized maleimides.     

Scalable Synthesis of Robust MOF for Challenging Ethylene Purification and Propylene Recovery with Record Productivity

Ethylene (C₂H₄) purification and propylene (C₃H₆) recovery are highly relevant in polymer synthesis, yet developing physisorbents for these industrial separation faces the challenges of merging easy scalability, economic feasibility, high moisture stability with great separation efficiency. Herein, we reported a robust and scalable MOF (MAC-4) for simultaneous recovery of C₃H₆ and C₂H₄. Through creating nonpolar pores decorated by accessible N/O sites, MAC-4 displays top-tier uptakes and selectivities for C₂H₆ and C₃H₆ over C₂H₄ at ambient conditions. Molecular modelling combined with infrared spectroscopy revealed that C₂H₆ and C₃H₆ molecules were trapped in the framework with stronger contacts relative to C₂H₄. Breakthrough experiments demonstrated exceptional separation performance for binary C₂H₆/C₂H₄ and C₃H₆/C₂H₄ as well as ternary C₃H₆/C₂H₆/C₂H₄ mixtures, simultaneously affording record productivities of 27.4 and 36.2 L kg⁻¹ for high-purity C₂H₄ (≥99.9 %) and C₃H₆ (≥99.5 %). MAC-4 was facilely prepared at deckgram-scale under reflux condition within 3 hours, making it as a smart MOF to address challenging gas separations.     

Accelerated Dynamic Reconstruction in Metal–Organic Frameworks with Ligand Defects for Selective Electrooxidation of Amines to Azos Coupling with Hydrogen Production

Electrosynthesis coupled hydrogen production (ESHP) mostly involves catalyst reconstruction in aqueous phase, but accurately identifying and controlling the process is still a challenge. Herein, we modulated the electronic structure and exposed unsaturated sites of metal–organic frameworks (MOFs) via ligand defect to promote the reconstruction of catalyst for azo electrosynthesis (ESA) coupled with hydrogen production overall reaction. The monolayer Ni-MOFs achieved 89.8 % Faraday efficiency and 90.8 % selectivity for the electrooxidation of 1-methyl-1H-pyrazol-3-amine (Pyr−NH₂) to azo, and an 18.5-fold increase in H₂ production compared to overall water splitting. Operando X-ray absorption fine spectroscopy (XAFS) and various in situ spectroscopy confirm that the ligand defect promotes the potential dependent dynamic reconstruction of Ni(OH)₂ and NiOOH, and the reabsorption of ligand significantly lowers the energy barrier of rate-determining step (*Pyr−NH to *Pyr−N). This work provides theoretical guidance for modulation of electrocatalyst reconstruction to achieve highly selective ESHP.     

Pharmacokinetics,tissue distribution,and plasma protein binding ratio of bicuculline following intragastric and intravenous administration in rats using ultra-high-performance liquid chromatography–tandem mass spectrometry

Bicuculline is a natural isoquinoline alkaloid that works as a gamma-aminobutyric acid receptor antagonist. It is widely found in Papaveraceae plants used in traditional Chinese medicines. Bicuculline not only has been shown to have favorable analgesic, memory-improving, and anxiolytic effects but may also cause adverse effects such as convulsions and epilepsy. A simple, rapid, and sensitive method was developed and validated for the determination of bicuculline in the plasma and tissue samples in rats by ultra-high-performance liquid chromatography–tandem mass spectrometry (MS/MS). The chromatographic separation was performed on a Thermo Scientific C18 column. The MS/MS system was operated in the positive multiple reaction monitoring mode, and the precursor–product ion transitions were optimized as m/z 368.0 → 307.1 for bicuculline and as 354.1 → 188.1 for protopine (internal standard). The linearity, accuracy, precision, recovery, and matrix effect were within acceptable limits. The experimental data showed that bicuculline was rapidly absorbed and eliminated in rats, with a moderate plasma protein binding ratio and low bioavailability. The main tissues of distribution were the kidney, liver, and brain; bicuculline could exert its pharmacological effects across the blood–brain barrier. This study has positive implications for the clinical use of herbal medicines containing bicuculline and for further development.     

Effect of annealing on the morphology and properties of poly(lactic acid)/polyhedral oligomeric silsesquioxane asymmetric porous membranes prepared through non-solvent induced phase separation and its application

Non-solvent induced phase separation (NIPS) method was employed to fabricate biodegradable poly(lactic acid) (PLA) nanocomposite membranes. Morphological studies using scanning electron microscopy revealed that all the membranes prepared display asymmetric structures comprising finger-like macropores. The incorporation of modified polyhedral oligomeric silsesquioxane (POSS) particles into the PLA matrix resulted in enhanced crystallinity, mechanical, and thermal properties. Annealing of the membranes was performed to explore the influence of temperature on the morphology and properties. After annealing, membranes become more thin and compact, and drastic enhancement in crystallinity is also observed. Consequently, Young's modulus experiences a significant improvement. The reduction in oil absorption capacity after annealing can be attributed to the higher level of crystallinity, reduced porosity, and smaller pore diameter observed in the annealed membranes. Additionally, the unannealed PLA nanocomposite membranes demonstrated exceptional oil absorption capacity, reaching approximately 88%. It is foreseeable that these PLA/POSS nanocomposite membranes possess the potential to be utilized as effective tools for oil–water separation, offering the advantage of mitigating secondary pollution.     

In Silico Design and SAR Study of Dibenzyl Trisulfide Analogues for Improved CYP1A1 Inhibition

Dibenzyl trisulfide (DTS) is a natural compound with potential cancer-preventive properties occurring in Petiveria alliacea L., an ethnomedicinal plant native to the Americas. Previous studies revealed its inhibitory activity toward cytochrome P450 (CYP)1 enzymes, key in the activation of environmental pollutants. Accordingly, the aim of this study was to design novel DTS analogues, aimed at improving not only inhibitory activity, but also specificity toward CYP1A1. This was achieved by targeting interactions with CYP1A1 residues of identified importance. Three-dimensional structures for the novel analogues were subjected to molecular docking with several CYP isoforms, before being ranked in terms of binding affinity to CYP1A1. With three hydrogen bond donors, two hydrogen bond acceptors, a molecular mass of 361 Da, and a log P of 3.72, the most promising DTS analogue obeys Lipinski's rule of five. Following synthesis and in vitro validation of its CYP1A1-inhibitory properties, this compound may be useful in future cancer-preventive approaches.     

Complex dynamics of epidemic models on adaptive networks

There has been a substantial amount of well mixing epidemic models devoted to characterizing the observed complex phenomena (such as bistability, hysteresis, oscillations, etc.) during the transmission of many infectious diseases. A comprehensive explanation of these phenomena by epidemic models on complex networks is still lacking. In this paper we study epidemic dynamics in an adaptive network proposed by Gross et al., where the susceptibles are able to avoid contact with the infectious by rewiring their network connections. Such rewiring of the local connections changes the topology of the network, and inevitably has a profound effect on the transmission of the disease, which in turn influences the rewiring process. We rigorously prove that the adaptive epidemic model investigated in this paper exhibits degenerate Hopf bifurcation, homoclinic bifurcation and Bogdanov–Takens bifurcation. Our study shows that adaptive behaviors during an epidemic may induce complex dynamics of disease transmission, including bistability, transient and sustained oscillations, which contrast sharply to the dynamics of classical network models. Our results yield deeper insights into the interplay between topology of networks and the dynamics of disease transmission on networks.     

Convenient Preparation of Cycloalkenyl Boronic Acid Pinacol Esters

A practical method for the preparation of cycloalkenyl boronic acid pinacol esters is described. These important synthetic intermediates are typically made using more expensive methods like transition metal-catalyzed borylation of alkenyl halides or triflates. In this work, they are obtained from the simple corresponding cycloalkanones, which are subjected to Shapiro reaction conditions followed by trapping with a borate ester. The requisite products are obtained in very good to excellent yields, and the reactions can be scaled up to multigram amounts. By providing a simple alternative to common methods that make use of expensive transition-metal catalysts and formation of sensitive intermediates, this convenient method will be useful for the synthesis of ring-containing partners for Suzuki–Miyaura cross-coupling and other reactions employing boronic esters as substrates.