Abstract Reprogramming the transport preference of crystalline membranes offers a useful strategy for adapting a single membrane platform to different gas-separation tasks. Herein, we report ionic liquid (IL) engineering of pure ZIF-8 membranes to switch H2/CO2 transport from H2- to CO2-preferential behavior. A continuous ZIF-8 membrane was first fabricated on an anodic aluminum oxide support by cathodic deposition, followed by the loading of an IL of type 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIM][TFSI]). The compact, well-intergrown, and crystalline ZIF-8 membrane was preserved after IL incorporation, and vibrational spectroscopy provided evidence for molecular interactions between confined [BMIM][TFSI] and the ZIF-8 framework. Gas-permeation measurements revealed that increasing IL loading decreased both H2 and CO2 permeances, indicating an increased transport resistance caused by partial pore occupation. However, the H2 permeance decreased significantly more rapidly than the CO2 permeance. The H2/CO2 selectivity decreased from 3.6 for the pristine ZIF-8 membrane to approximately 0.3 at 15 vol % ionic-liquid loading, corresponding to a CO2/H2 selectivity close to 3. The separation reversal originates from the combined effects of IL-induced pore narrowing and preferential CO2 affinity. This work demonstrates that confined ILs can reprogram adsorption–diffusion coupling in MOF membranes and provides a route toward process-adaptive gas-separation membranes.
Abstract Thermoelectric (TE) Ag2Se was synthesized via an energy-efficient, solution-based chemical synthesis route with microwave-assisted heating and compacted by sustainable cold pressing. Structural and TE transport property analyses confirmed a highly crystalline microstructure that promotes high electrical conductivity, a large Seebeck coefficient, and low thermal conductivity, yielding a peak TE figure of merit (ZT) of ∼0.85 at room temperature. To evaluate device-level performance, Ag2Se was employed as the n-type TE leg in modules paired with Sb1.5Bi0.5Te3 (ZT ∼1.1 at 325 K) as the complementary p-type TE leg. Both rigid and flexible modules, each containing 58 thermocouple pairs, were fabricated and benchmarked against a commercial TEC1-12706 module. The rigid module exhibited more than four times the maximum power output of the commercial reference, highlighting the promise of Ag2Se for low-temperature TE power applications. Cooling performance tests demonstrated the critical influence of electrical configuration. Series-connected rigid modules achieved the lowest cold-side temperatures at lower input power, reaching ∼2 °C at 18 W, comparable to or exceeding the cooling performance of the commercial device. In contrast, parallel-connected modules exhibited stronger initial cooling but were hindered by excessive current draw, Joule heating, and thermal instability, preventing stable saturation. Increasing input power would enhance cooling performance until saturation limits were reached. These results emphasize the importance of module architecture and thermal management for optimizing TE device performance. Overall, this work establishes Ag2Se as a promising alternative to conventional Bi-Sb-Te-based n-type materials, demonstrating versatility in both rigid and flexible TE modules for energy harvesting and cooling technologies.
Abstract Oral ulcers are a common mucosal disorder that causes persistent pain and significantly impairs quality of life for patients. Current therapeutic approaches, including sprays and commercial patches, provide only temporary relief, as the complex, dynamic, and moist oral environment hinders prolonged retention and drug efficacy. Here, we report the rational design of a multifunctional hydrogel adhesive that integrates poly(acrylic acid) (PAA) for hydrogen bonding, polyamidoamine-epichlorohydrin (PAE) for electrostatic interactions with mucosal surfaces, and poly(methyl methacrylate) (PMMA) for swelling resistance. The resulting hydrogel exhibits an instant wet tissue adhesion strength of ∼40 kPa and enhances adhesion after prolonged immersion in phosphate-buffered saline (PBS). Remarkably, it retains high adhesion strength under extreme conditions, such as hypertonic and strongly acidic environments. When loaded with dexamethasone acetate, the hydrogel enables controlled drug release, significantly improving therapeutic outcomes in a rat oral ulcer model. By ensuring prolonged retention and effective drug delivery, this hydrogel patch offers a promising strategy for enhancing oral ulcer treatment.
Abstract Sustainable recycling of graphite anodes is critical for enabling closed-loop lithium-ion battery manufacturing, yet most direct recycling methods rely on organic solvents and corrosive acid treatments that increase costs and environmental impacts. Herein, we evaluate an organic solvent-free, direct recycling strategy that combines aqueous graphite recovery with boric acid-assisted regeneration. Water-based delamination of graphite black mass was investigated using two representative commercial end-of-life graphite anodes and a commercially manufactured uncycled graphite anode. The effectiveness of aqueous separation of the black mass from the Cu current collector was investigated along with rapid thermal processing (RTP), which has been proposed to improve graphite recovery through binder degradation. Both methods resulted in effective graphite recovery despite impurities originating from ceramic-coated separators, Ti-containing additives, and current collector corrosion. However, delamination of RTP-treated spent anodes was more difficult than pristine anodes, requiring pre-RTP washing and ultrasonication for efficient graphite recovery. Boric acid treatment followed by calcination at 1050 °C increased the degree of graphitization for all spent graphite samples while removing residual surface species and trapped lithium. Electrochemical testing showed that the regenerated graphite largely recovered its capacity and electrochemical activity, although residual metallic impurities may limit long-term cycling stability. Overall, aqueous delamination combined with boric acid-assisted regeneration provides an effective and more sustainable route for graphite recycling by eliminating organic solvents and strong mineral acids while preserving favorable structural and electrochemical properties. This process offers a promising pathway for scalable, environmentally responsible recovery of graphite from end-of-life lithium-ion batteries.
Abstract Covalent organic frameworks (COFs) have attracted much attention for their potential in photocatalytic hydrogen peroxide (H2O2) production. However, traditional COFs often suffer from sluggish charge transfer kinetics and a lack of highly electron-localized sites for O2 adsorption, leading to inefficient photocatalytic activity. Herein, we report a pore-channel electronic engineering strategy that introduces highly electron-localized cores into the pore channels of COFs by the regulation of heterocyclic pendants. The cores located in the channel of COFs acted as electron-rich active sites, enabling enhanced charge separation for photocatalytic H2O2 production. The polar furan groups were introduced onto the cores, further forming a powerful built-in electric field and hydrogen bond network within the channels, thereby accelerating the transport of electrons and protons. The furan-grafted COF (O-COF) showed a photocatalytic H2O2 production rate of 15,378 µmol h–1 g–1, with a yield 1.5–2.4 times higher than that of its counterparts. This work provides a valuable reference for the precise electronic regulation of pore channels in COFs to enhance photocatalytic performances.
