Aqueous Zn-ion batteries (AZIBs) are promising candidates for grid-scale energy-storage applications, but uneven Zn2+ flux distribution and undesirable water-related interfacial side reactions seriously hinder their practical application. Herein, a strategy of regulating the coordination interaction between Zn2+ and artificial interphase layers (AILs) to modulate the interfacial Zn2+ desolvation/transport behaviors and relieve side reactions for building stable Zn anodes is proposed. By selectively choosing appropriate polymers with different functional groups, it is shown that compared with the strong interaction offered by aryl groups in polystyrene-based AILs, cyano groups in polyacrylonitrile (PAN)-based AILs provide a moderate coordination interaction with Zn2+, which not only accelerates interfacial Zn2+desolvation kinetics but also enables efficient Zn2+ transport within AILs. Moreover, the Zn2+ transport kinetics of PAN-based AILs can be further enhanced with the incorporation of an ionic conductor, zinc phosphate (ZP). Because of these advantages, the Zn anodes decorated with the hybrid AILs composed of PAN and ZP can steadily operate for >2000 h at 0.2 mA cm-2 and >350 h at a high current density of 10 mA cm-2. This work provides a valuable guideline for selective design of AILs at the molecular level for durable AZIBs.

Covalent organic frameworks (COFs) are attractive materials for sample pretreatment due to their tunable structures and functions. However, the precise recognition of contaminant in complex environmental matrices by COFs remains challenging owing to their insufficient specific active sites. Herein, we report Co2+ coordination-assisted molecularly imprinted flexible COF (MI-COF@Co2+) for selective recognition of ochratoxin A (OTA). The MI-COF@Co2+ was prepared via one-step polymerization of 3,3-dihydroxybenzidine, 2,4,6-tris(4-formylphenoxy)- 1,3,5-triazine, Co2+ and template. The flexible units endowed COFs with the self-adaptable ability to regulate the molecular conformation and coordinate with Co2+ to locate the imprinted cavities. The coordination interaction greatly improved the adsorption capacity and selectivity of MI-COF@Co2+ for OTA. The prepared MI-COF@Co2+ was used as solid phase extraction adsorbent for high-performance liquid chromatography determination of OTA with the detection limit of 0.03 ng mL-1 and the relative standard deviation of < 2.5 %. In addition, this method permitted interference-free determination of OTA in real samples with recovery from 89.5 % to 102.8 %. This work provides a simple way to improve the selectivity of COFs for the determination of hazardous compounds in complex environments.

Functionalization of graphene enables precise control over interlayer spacing during film formation, thereby enhancing the separation efficiency of radioactive ions in graphene membranes. However, the systematic impact of interlayer spacing of graphene membranes on radioactive-ion separation remains unexplored. This study aims to elucidate how interlayer spacing in functionalized graphene membranes affects the separation of radioactive ions. Utilizing polyamidoxime (PAO) to modify graphene oxide, we controlled the interlayer spacing of graphene membranes. Experimental results indicate that tuning interlayer spacing enables control of the permeation flux of radioactive ions (UO22+ 1.01 × 10-5-8.32 × 10-5 mol/m2·h, and K+ remains stable at 3.60 × 10-4 mol/m2·h), and the K+/UO22+ separation factors up to 36.2 at an interlayer spacing of 8.8 Å. Using density functional theory and molecular dynamics simulations, we discovered that the effective separation is mainly determined via interlayer spacing and the quantity of introduced functional groups, explaining the anomalous high permeation flux of target ions at low interlayer spacing (4.3 Å). This study deepens our comprehension of interlayer spacing within nanoconfined spaces for ion separation and recovery via graphene membranes, offering valuable insights for the design and synthesis of high-performance nanomembrane materials.

The development of smart systems for pesticidal delivery presents a significant advancement in enhancing the utilization efficiency of pesticides and mitigating environmental risks. Here an acid-responsive pesticidal delivery system using microspheres formed by the self-assembly of halloysite clay nanotubes (HNTs) is proposed. Insecticide avermectin (AVM) and herbicide prometryn (PMT) are used as two models of hydrophobic pesticide and encapsulated within the porous microspheres, followed by a coating of tannic acid/iron (TA/FeIII) complex films to generate two controlled-release pesticides, named as HCEAT and HCEPT, resulting in the loading capacity of AVM and PMT being 113.3 and 120.3 mg g-1, respectively. Both HCEAT and HCEPT exhibit responsiveness to weak acid, achieving 24 h-release ratios of 85.8% and 80.5% at a pH of 5.5. The experiment and simulation results indicate that the coordination interaction between EDTA2- and Ca2+ facilitates the spherical aggregation of HNTs. Furthermore, these novel pesticide formulations demonstrate better resistance against ultraviolet (UV) irradiation, higher foliar affinity, and less leaching effect, with negligible impact of the carrier material on plants and terrestrial organisms. This work presents a promising approach toward the development of efficient and eco-friendly pesticide formulations, greatly contributing to the sustainable advancement of agriculture.

Adsorption for recovery of low-concentration platinum (Pt) from the complex composition of acidic digestates was challenging because of slow kinetic and poor affinity. It was expected to be overcome by the improvement of pore size distribution and adsorption site activity. Herein, a series of Prussian blue etchings (PBE) with porosity-rich and activity-high cyano (CN) was synthesized to recover low-concentration Pt. The N2 isotherm results showed that the pore structure evolved from mesoporous to microporous. The Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculations results revealed that the modulation of electronic structure converted FeII to FeIII in [FeII(CN)6]4-. The coexistence of micro- and meso-pore structures provided channels to accelerate adsorption and ensured PtII enrichment. The regulation of Fe valence state activated CN, which reinforced the strength of coordination interaction between Pt and Fe-CN- at N-atom. The adsorption rate and maximum capacity of PBE1 were 4.4 and 2.5 times higher than those of PB, respectively, due to the dual efficacy of accelerated kinetic and reinforced coordination. This study systematically analyzes the pivotal role of pore and electronic structure modulation in adsorption kinetic and affinity, which provides a novel strategy for PtII targeted recovery.

Zinc-based aqueous batteries (ZABs) are attracting extensive attention due to the low cost, high capacity, and environmental benignity of the zinc anode. However, their application is still hindered by the undesired zinc dendrites. Despite Zn-surface modification being promising in relieving dendrites, a thick separator (i.e. glass fiber, 250-700 μm) is still required to resist the dendrite puncture, which limits volumetric energy density of battery. Here, we pivot from the traditional interphase plus extra separator categories, proposing an all-in-one ligand buffer layer (ca. 20 μm) to effectively modulate the Zn2+ transfer and deposition behaviors proved by in situ electrochemical digital holography. Experimental characterizations and density functional theory simulations further reveal that the catechol groups in the buffer layer can accelerate the Zn2+ reduction reaction (ZRR) through the electron-donating p-π conjugation effect, decreasing the negative charge in the coordination environment. Without extra separators, the elaborated system endows low polarization below 28.2 mV, long lifespan of 4950 h at 5 mA cm-2 in symmetric batteries, and an unprecedented volumetric energy density of 99.2 Wh L-1 based on the whole pouch cells. The concomitantly \"separator-free\" and \"dendrite-free\" conjugation effect with an accelerated ZRR process could foster the progression of metallic anodes and benefit energetic aqueous batteries.

In this study, a novel composite material was developed for the ratiometric detection of pyrophosphate anion (P2O74-). This composite consisted of Al and nitrogen co-doped carbon dots (Al-N@CQDs) and glutathione-capped copper nanoclusters (GSH@CuNCs). The Al-N@CQDs component, with its high reserved coordination capacity of Al3+, induced the non-luminescent behavior of GSH@CuNCs, resulting in an aggregation-induced emission (AIE) effect. The hybrid material (Al-N@CQDs/GSH@CuNCs) exhibited dual-emission signals at 620 nm and 450 nm after integrating the two independent materials utilizing the AIE effect and the fluorescence resonance energy transfer (FRET) approach. This approach represents the first utilization of this composite for ratiometric detection. Nevertheless, upon the addition of P2O74-, the AIE and FRET processes were hindered due to the higher coordination interaction of Al3+ towards P2O74- compared to the amino/carboxyl groups on Al-N@CQDs. This successful interference of the AIE and FRET processes allowed for the effective estimation of P2O74-. The response ratio (F450/F620) increased with increasing the concentration of P2O74- in the range of 0.035-160 µM, with an impressive detection limit of 0.012 µM. This innovative approach of utilizing hybrid CQDs/thiolate-capped nanoclusters as a ratiometric fluorescent sensor for analytical applications introduces new possibilities in the field. The as-fabricated system was successfully applied to detect P2O74- in different real samples such as water, serum, and urine samples with acceptable results.

Herein, a new type of super active nitrogen-doped biochar sheet (SNBC) was prepared by two-step pyrolysis and KOH chemical activation with melamine and cherry kernel powder as precursors of nitrogen and carbon source for removing Hg2+ from wastewater. The N2 adsorption/desorption and scanning electron microscope characterization revealed that the resulted SNBC under 600 °C calcination owned huge specific surface area of 2828 m2/g and plenty of well-developed micropores, and X-ray photoelectron spectroscopy and Fourier transform-infrared spectroscopy analysis testified the existence of functional groups containing N and O, which could provide adsorption sites for Hg2+. The SNBC-600 showed high adsorption capacity for Hg2+ even at low pH, and interfering cations had little effect on the adsorption. The adsorption process was rapid and dynamic data fit the pseudo-second-order dynamic model well. The maximum adsorption capacity of Hg2+ on SNBC-600 calculated by Langmuir model was 230 mg/g. After six times of reuse, the adsorption capacity still exceeded 200 mg/g, exhibiting good reusability. The designed microfiltration membrane device base on SNBC-600 could remove low concentration of Hg2+ effectively from solution. This study provided a simple and environment-friendly method for manufacturing nitrogen-doped biochar sheet, which was of great significance in the practical application of Hg2+ pollution treatment.

Recently, many tough synthetic hydrogels have been created as promising candidates in fields such as smart electronic devices. In this paper, we propose a simple strategy to construct tough and robust hydrogels. Two-dimensional Ti3C2Tx MXene nanosheets and metal ions were introduced into poly(acrylamide-co-acrylic acid) hydrogels, the MXene nanosheets acted as multifunctional cross-linkers and effective stress-transfer centers, and physical cross-links were formed between Fe3+ and carboxylic acid. Under deformation, the coordination interactions exhibit reversible dissociation and reorganization properties, suggesting a novel mechanism of energy dissipation and stress redistribution. The design enabled the hydrogel to exhibit outstanding and balanced mechanical properties (tensile strength of up to 5.67 MPa and elongation at break of up to 508%). This study will facilitate the diverse applications of metallosupramolecular hydrogels.

Magnetic-assisted DNA testing technology has attracted much attention in genetics, clinical diagnostics, environmental microbiology, and molecular biology. However, achieving satisfying DNA adsorption and desorption efficiency in real samples is still a big challenge. In this paper, a new kind of high-quality magnetic composite microsphere of MM@PGMA-PA-Ti4+ was designed and prepared for DNA extraction and detection based on the strong interaction of Ti4+ and phosphate groups. By taking the advantages of high magnetic susceptibility and high Ti4+ content, the MM@PGMA-PA-Ti4+ microspheres possessed remarkable extraction capacity for mimic biological samples (salmon sperm specimens) with saturated loadings up to 533.0 mg/g. When the DNA feeding amount was 100 μg and the MM@PGMA-PA-Ti4+ dosage was 1 mg, the adsorption and desorption efficiencies were 80 and 90%, respectively. The kinetic and equilibrium extraction data were found to fit well with the pseudo-second-order model and Freundlich isotherm model. Furthermore, the MM@PGMA-PA-Ti4+ microspheres were successfully employed for DNA extraction from mouse epithelial-like fibroblasts. The extraction ability (84 ± 4 μg/mg) and DNA purity were superior to the comparative commercial spin kits, as evaluated by electrophoresis assays and qPCR analysis. The experimental results suggest that the MM@PGMA-PA-Ti4+ microspheres possess great potential as an adsorbent for DNA purification from complex biological samples.