Strong Coordination Research Articles

Dual fluorophores embedded in zeolitic imidazolate framework‑8 for ratiometric fluorescence sensing of a biomarker of anthrax spores

The precise and selective monitoring of dipicolinic acid (DPA), a particular biomarker associated with anthrax spores, is crucial for the rapid detection and diagnosis of anthrax infection. A ratiometric fluorescence nanoprobe called AuNCs/GQDs@ZIF-8, has been designed by encapsulating gold nanoclusters (AuNCs) and graphene quantum dots (GQDs) into zeolitic imidazolate framework‑8 (ZIF-8) for sensing DPA. By leveraging enrichment effects of ZIF-8, embedded AuNCs restricts intramolecular movements and triggers aggregation-induced emission, further acquiring bright fluorescence. In the presence of europium ions (Eu3+), the fluorescence of AuNCs@ZIF-8 significantly decreases due to static quenching. However, Eu3+ are sequestered by DPA through strong coordination effects, causing fluorescence recovery of AuNCs@ZIF-8. Eu3+-mediated AuNCs@ZIF-8 therefore serve as response signals for DPA recognition. Integrating with stable reference signals of GQDs, a ratiometric fluorescence sensor exhibits the satisfactory linearity of 0.1–200 µM and detection limit of 32 nM. Furthermore, the smartphone-integrated visual mode can immediately identify fluorescence colors for assessing DPA. Compared to alternative nanoprobes, this ratiometric fluorescence sensor demonstrates higher sensitivity, lowering than DPA commonly released by infectious spores (60 µM). This study not only provides the promising sensor for DPA measurement during early anthrax diagnosis, but offers insights on designing ratiometric sensors with diverse fluorescence nanomaterials.

Lean-water hydrogel electrolyte with improved ion conductivity for dendrite-free zinc-Ion batteries

Although rechargeable aqueous zinc-ion batteries (ZIBs) are regarded as promising energy storage devices, the uncontrollable Zn dendrite and undesirable side reactions severely limit their practical applications. Herein, an anionic hydrogel electrolyte PAM/SA with 3D porous structures is developed by integrating sodium alginate (SA) and polyacrylamide (PAM) networks for highly reversible Zn plating/stripping. Mechanically enhanced and lean-water PAM/SA hydrogel with anionic chains for constructing ionic channels and molecular lubrication films, which facilitate Zn2+ migration for a high ionic conductivity (5.4 S m−1) and Zn2+ transference number (0.86) even under lean-water conditions (about 60%). Based on the experimental and theoretical analysis, the SA chain with strong coordination ability endows PAM/SA with improved desolvation kinetics and the ability to regulate the electric field intensity at the electrode/electrolyte interface, which is beneficial for suppressing side reactions and facilitating directional Zn deposition. Subsequently, the symmetric Zn//Zn cell based on PAM/SA hydrogel electrolyte delivers stable cycles for over 1800 h. The assembled Zn//V2O5 battery based on PAM/SA reveals a high specific capacity and a long cycle life. This work provides a new insight for developing hydrogel electrolytes with high ionic conductivity and lean-water properties toward stable Zn anode

Regulating local charge distribution of single Ni sites in covalent organic frameworks for enhanced photocatalytic CO2 reduction

Covalent organic frameworks (COFs) engineered by single-atom sites have attracted significant attention for CO2 photoreduction. However, precisely manipulating the chemical environment of active sites on the COFs is a grand challenge. Herein, we synthesized a series of isostructural COFs for photocatalytic CO2 reduction, where the strong coordination conformation guides atomically dispersed metal sites to chelate spontaneously in the predesigned imine-pyridine position of COFs. Experimental and theoretical results revealed the crucial influence of the single-Ni site engineering and electronic structures of COF configuration on improving extended π-conjugation, exciton dissociation, charge separation efficiency, and charge carrier migration. Benefiting from the synergistic effect, the optimal Ni-TAPT-COF exhibited a record-high CO production rate of 25.5 mmol g-1h-1 and a selectivity of 98.8%, even natural-sunlight-driven diluted CO2 (10%). This work paves the way for the rational design of high-performance COF-based photocatalysts at the molecular level, highlighting their practical potential for CO2 photoreduction.

Molecular dynamics simulation study of sodium ion structure & dynamics in water in ionic liquids electrolytes using 1-butyl-3-methyl imidazolium tetrafluoroborate and 1-butyl-3-methyl imidazolium hexafluorophosphate

In this paper, we have performed an all-atom molecular dynamics simulation to understand the structure and dynamics of Na+ ions in water mixed Ionic liquids (Water in Ionic liquid). Two ionic liquid (IL) systems consist of (1) 1-butyl-3-methylimidazolium [BMIM] tetrafluoroborate [BF4] and (2) 1-butyl-3-methylimidazolium [BMIM] hexafluorophosphate [PF6] were considered in this work. We understand various inter-molecular structures and dynamic and thermodynamic behaviours of Na+ ions in the water-mixed IL systems. The water (H2O) mole fractions (x) varied from 0.33 to 0.71. The neat ILs [BMIM][BF4] and [BMIM][PF6] pairwise radial distribution functions show a decrease with an increase in x. The [BMIM][PF6] exhibits a strong coordination structure with Na+ ions across the entire range of x values. The rdf between the pairs of Na+-[PF6] presents a significant interaction compared to Na+ and [BF4]. The Na + ions manifested greater coordination with H2O In H2O-[BMIM][PF6] compared to H2O-[BMIM][BF4]. The self-diffusion coefficient (D) values of Na + ions increase with the rise in x in both ILs. The D values of Na + ions are 10-fold higher in [BMIM][BF4] than [BMIM][PF6]. The ionic conductivity values are higher for [BMIM][BF4]. Overall, this paper unveils molecular-level insights for understanding the behavior of Na+ ions in the water in ionic liquid systems.

Bi‐Functional Chelating Ligand Enables Ultra‐Stable Blue Emissive CsPbBr3 Nanoplatelets Film

AbstractQuantum‐confined perovskite CsPbBr3 Nanoplatelets (NPLs) have recently emerged as promising blue‐emitting materials for perovskite light‐emitting diodes (PeLEDs). Yet, their susceptibility to optical instability in solid films under ambient conditions poses a significant hindrance. This study introduces a novel chelating strategy that utilizes metal manganese ions and multidentate ligands, markedly improving the structural stability, and emission efficiency of NPLs. The approach involves adding Diethylenetriaminepentaacetic acid (DTPA) to the perovskite precursor solution, which allows for strong coordination to surface [PbBr6]4− octahedrons via its multiple chelation sites. Ensuing metal manganese ion integration during the purification phase addresses Pb2+ and Br− site vacancies, culminating in near‐perfect octahedral structures with significantly fewer vacancies. These metal manganese ions are then further immobilized on the NPLs surface by the chelating effect of unbound DTPA functional groups. The resultant CsPbBr3 NPLs films demonstrate an impressive PLQY of 66%, showcasing remarkable air stability with consistent blue emission for up to 5 days. The CsPbBr3 NPLs‐based PeLEDs show electroluminescence at 460 nm with a current efficiency of 1.07 cd A−1 and a maximum luminance of 220 cd m−2. The proposed chelating strategy positions perovskite NPLs as an extremely promising prospect in future applications of high‐definition displays and high‐quality lighting.

Immobilized transition metal (II) bis–imine chelate on ZnO@TiO2 nanoparticles as sufficient catalysts for alcohol oxidation and for α,β‐cinnamic acid decarboxylative bromination

Based on the strong coordination ability of substituted imines towards transition metals of different oxidation states, the coordination of the HL imine ligand with the Cu2+ ion to form the Cu–bis–imine complex was achieved in 2:1 molar ratios. Their structures were confirmed with various spectroscopic tools. Heterogeneously, CuL2 was successfully appended on ZnO@TiO2 nanoparticles, as the less harmful materials, within the deprotonated p‐hydroxy chain of the bonded ligand in CuL2. The surface and internal structural morphologies of ZnO@TiO2@CuL2 were analyzed using X‐ray diffraction (XRD), field‐emission scanning electron microscopy (FESEM), high‐resolution transmission electron microscopy (HRTEM), energy‐dispersive X‐ray spectroscopy (EDS), and infrared (IR) spectroscopy, in addition to thermogravimetric analysis (TGA). The catalytic behavior of both catalysts, CuL2 (the homogeneous catalyst) and ZnO@TiO2@CuL2 (the heterogeneous catalyst), was examined in the benzyl alcohol redox protocols using H2O2 for their optimization. α,β‐Cinnamic acid decarboxylative bromination in the presence of potassium bromide and H2O2 in water was studied with both catalysts, in which (2‐bromovinyl)benzene was the chemoselective product. Both Cu catalysts displayed appreciable catalytic effectiveness for the oxidation protocols and the decarboxylative bromination reactions. CuL2 recorded less required time for optimization than that of the heterogeneous catalyst. The catalytic effectiveness of CuL2 was less promoted than that of ZnO@TiO2@CuL2. Despite the less performance in yield of benzaldehyde for the oxidation protocols with ZnO@TiO2@CuL2, ZnO@TiO2@CuL2 had more recycling than its homogeneous counterpart, with seven to three times, respectively.

4‐Phenylthiosemicarbazide Molecular Additive Engineering for Wide‐Bandgap Sn Halide Perovskite Solar Cells with a Record Efficiency Over 12.2%

AbstractThe utilization of wide bandgap (WBG) tin halide perovskites (Sn‐HPs) offers an environmentally friendly alternative for multi‐junction Sn‐HP photovoltaics. Nonetheless, rapid crystallization leads to suboptimal film morphology and substantial creation of defect states, which undermine device efficiency. This study introduces 4‐Phenylthiosemicarbazide (4PTSC) as an additive to achieve a densely packed Sn‐HP film with fewer imperfections. The strong chemical coordination between SnI2 and the functional groups S═C─N (Sn···S═C─N), NH2, and phenyl conjugation enhances solution stability and supports the delay of perovskite crystallization through adduct formation. This process yields pinhole‐free films with preferred grain growth. 4PTSC acts as a strong coordination complex and a reducing agent to passivate uncoordinated Sn2+ and halide ions and reduce the formation of SnI4, thereby reducing defect formation. The π‐conjugated phenyl ring in the 4PTSC facilitates the preferred crystal growth orientation of perovskite grains. Furthermore, the hydrophobic nature of 4PTSC mitigates Sn2+ oxidation by repelling moisture, enhancing stability. The open circuit voltage significantly increased from 0.78 to 0.94 V, resulting in achieving the champion efficiency of 12.22% (certified 11.70%), surpassing all previously reported efficiencies for WBG Sn halide perovskite solar cells. Additionally, the unencapsulated 4PTSC‐1.0 device maintained outstanding stability over 1200 h under ambient atmospheric conditions.

Ultrasensitive Label-Free Electrochemical Immunosensor for Carbohydrate Antigen-125 (CA125) Employing Cu(II)-Polyethyleneimine (PEI)/Silica Nanoparticle@Overoxidized Polypyrrole (OPPy)/Multi-Walled Carbon Nanotubes (MWNTs) Hybrid Nanomaterial

Novel electroactive nanotags of Cu(II) functionalized polyethylenimine (PEI)/SiO2 nanoparticles (abbreviated as Cu2+/PEI/SiO2 NPs) were conveniently synthesized using a strong coordination reaction between Cu(II) and the multi-amino groups of PEI. These electroactive nanotags were easily coated on the overoxidized polypyrrole (OPPy) modified Nafion/multi-walled carbon nanotubes (abbreviated as Nafion/MWNTs) electrode surface through Cu-N bonds and strong electrostatic interactions. The Cu2+/PEI/SiO2 NPs@OPPy/MWNTs hybrid nanomaterial was formed without the addition of extra membrane-forming substances. The experimental results demonstrate that the OPPy/MWNTs composite membrane coupled with electrocatalytic Cu(Tris)4 2+ complexes in tris(hydroxymethyl)aminomethane (Tris)-HCl buffer medium amplified the electrochemical signals of nanotags based on the mutual synergistic effects. As an application, a label-free electrochemical immunosensor for epithelial ovarian cancer biomarker-carbohydrate antigen-125 (CA125) was constructed by covalently immobilizing CA125 antibody onto the hybrid nanomaterial modified electrode. With the increasing concentrations of CA125 antigen, different decreases in the electrochemical signals of the nanotags were observed due to the formation of antigen-antibody immune complexes. The electrochemical immunosensor showed a linear relationship from 0.001 to 500 U·mL−1 for CA125 with a detection limit of 3.4 × 10−4 U·mL−1. In addition, the proposed immunosensor was applied to the determination of CA125 in human serum with satisfactory results.

Stabilizing Ni2+ in Hollow Nano MOF/Polymetallic Phosphides Composites for Enhanced Electrochemical Performance in 3D-Printed Micro-Supercapacitors.

Polymetallic phosphides exhibit favorable conductivities. A reasonable design of nano-metal-organic frame (MOF) composite morphologies and in situ introduction of polymetallic phosphides into the framework can effectively improve electrolyte penetration and rapid electron transfer. To address existing challenges, Ni, with a strong coordination ability with N, is introduced to partially replace Co in nano-Co-MOF composite. The hollow nanostructure is stabilized through CoNi bimetallic coordination and low-temperature controllable polymetallic phosphide generation rate. The Ni, Co, and P atoms, generated during reduction, effectively enhance electron transfer rate within the framework. X-ray absorption fine structure (XAFS) characterization results further confirm the existence of Ni-N, Ni-Ni, and Co-Co structures in the nanocomposite. The changes in each component during the charge-discharge process of the electrochemical reactions are investigated using in situ X-ray diffraction (XRD). Theoretical calculations further confirm that P can effectively improve conductivity. VZNPGC//MXene MSCs, constructed with active materials derived from the hollow nano MOF composites synthesized through the Ni2+ stabilization strategy, demonstrate a specific capacitance of 1184 mF cm-2, along with an energy density of 236.75 µWh cm-2 (power density of 0.14 mW cm-2). This approach introduces a new direction for the synthesis of highly conductive nano-MOF composites.

Metal Complexes of Adenine Azo Ligand: Synthesis, Identification and Study some of their Applications

This scientific paper presents two novel lanthanide metal complexes [Sm (III) and Ce (IV)] synthesized through a series of reactions involving organic ligand 8-[3-(pyrazoyl)azo]adenine (PAA). Ligand (PAA) and their complexes were characterized using various analytical techniques, including C.H.N.S elemental analysis, magnetic measurement, X-ray diffraction, thermal analysis, SEM, (TGA) UV-Vis spectroscopy, FT-IR spectroscopy, and HNMR analysis. These techniques were employed to support the mode of binding and geometrical structure for ligand (PAA) and its Lanthanide (Ln) complexes. The FTIR and HNMR spectral results showed that (PAA) acts as neutral N,N-bidentate with [Sm (III) and Ce (IV)]. The geometric shape of the synthesized Ln-complexes is octahedral. Also, TGA was used to investigate the thermal behavior of ligand and its complex. The results showed that the ligand dissociated in three steps, while the complex dissociated in five steps. This indicates that the complex is more thermally stable than the ligand, likely due to the formation of strong coordination bonds between the ligand and the metal ions. These findings can contribute to the understanding of the thermal stability of metal complexes and inform the design of new metal-based materials with desirable properties. Finally, this paper examined the antibacterial, antifungal and anticancer activities of PAA and its complexes. The results indicated that all of these compounds exhibited significant activity against bacterial and fungal pathogens, as well as cancer cells.

Self-Repairing [MEDTA]2- functionalized poly(ionic liquid)s in the application of NH3 adsorption through reversible NH3 insertion

MOFs have high adsorption performance of ammonia (NH3) because of its porosity and abundant coordination sites, especially MOFs containing carboxylic acid ligands have emerged as effect NH3 adsorbents. But, it’s troublous for reversible ammonia adsorption for the strong metal-NH3 coordination or the collapse of adsorbents. [MEDTA]2- is a very stable and classic carboxylic acid-containing complex, but there was no relevant report. Therefore, this work carried out the design and synthesis of PVIm-R8-MEDTA based on the use of the coordination structure of [MEDTA]2- and the stability of PILs’ skeleton. The characterization indicated the [MEDTA]2- could be introduced into PILs successfully for the hydrogen bonding interactions with the imidazolium cation, and the obtained PVIm-R8-MEDTA presented enhanced NH3 capacity (10.4–14.7 mmol/g) than their precursor PVIm-R8-Br (7.8 mmol/g). The mechanism of NH3 adsorption was proposed by DFT calculation, spectroscopic method, and the calorimetric test, it indicated the NH3 was fixed by imdazolium cation through hydrogen bonding and inserted into two of the carboxylate and metal bonds of [MEDTA]2-. Because of the multi-meshing coordination of [EDTA]4- and metal ions, the disconnected carboxylate ions could easily coordinate with metal ions again and repair the chelating structure of [MEDTA]2-, which caused the ammonia easily be desorbed. In the process of gas adsorption, there was no bonding breakage of the skeleton of PILs, which helped the PVIm-R8-MEDTA be recovered under moisture and NH3 atmosphere. Thanks for the designability of PILs, such as the cationic structure, structure and size of cross-linking agent, the choice of complex anion and so on, it provides a new design idea and theoretical basis for efficient and reversible ammonia adsorption materials.

Releasing Free Anions by High Donor Number Cosolvent in Noncorrosive Electrolytes of Commercially Available Magnesium Salts.

Passivation of the magnesium (Mg) anode in the chloride-free electrolytes using commercially available Mg salts is a critical issue for rechargeable Mg batteries. Herein, a high donor number cosolvent of 1-methylimidazolium (MeIm) is introduced into Mg(TFSI)2- and Mg(HMDS)2-based electrolytes to address the passivation problem and realize highly reversible Mg plating/stripping. Theoretical calculations and experimental characterization results reveal that the strong coordination ability of MeIm with Mg2+ can weaken the anion-cation interactions and promote the formation of free anions that have higher reduction stability, thus significantly suppressing anion-derived passivation layer formation. By adding MeIm cosolvent into Mg(TFSI)2-based electrolyte, the average Coulombic efficiency of the Mg//Cu cell is increased from less than 20% to over 90%, and the Mg//Mg cell can stably cycle for over 800 h with a low overpotential. In the MeIm-regulated Mg(HMDS)2-based electrolyte, the solvation structure change, featured by an effective separation of Mg2+ and HMDS-, greatly increases the ionic conductivity by more than 30 times. This solvation structure regulation strategy for noncorrosive electrolytes of commercially available Mg salts has a great potential for application in future rechargeable Mg metal batteries.

Ultra-low viscosity betaine hydrochloride-formic acid deep eutectic solvent for leaching critical metals from spent NCM lithium-ion batteries

With the rapid development of the electric vehicle market and increasing demand for lithium-ion batteries (LIBs), spent LIBs recycling has attracted extensive attention worldwide. Being environmentally friendly, deep eutectic solvents (DESs) have great potential for critical metal recycling from spent LIBs. In this study, a new type of DES, consisting of betaine hydrochloride (BeCl) and formic acid (FA) in a 1BeCl:9FA molar ratio, was designed to leach critical metals from spent LIBs cathode materials. The study found that the as-prepared DESs exhibited extremely low viscosities and strong coordination abilities, which are suitable for metal leaching. By properly regulating and controlling the leaching parameters, the Li, Mn, Co, and Ni leaching efficiencies from spent LiNi0.8Co0.1Mn0.1O2 LIBs reached 98.03, 96.01, 94.19, and 92.35%, respectively, whereas those of critical metals were all > 99.5% from either LiCoO2 or LiMn2O4. The leaching kinetics revealed that the leaching process was controlled by the interfacial chemical reaction, and the leaching mechanism indicated that the highly efficient critical metal leaching was the result of the strong coordination capacity (Cl-), acidity (H+), and reduction capacity (FA) synergistic effect in the DES. This study provides a novel, environmentally friendly, and efficient strategy for critical metals recovery from spent LIBs.

Composition regulation of polyacrylonitrile-based polymer electrolytes enabling dual-interfacially stable solid-state lithium batteries

The polyacrylonitrile (PAN) is an attractive matrix of polymer electrolytes owing to its wide electrochemical window and strong coordination with Li salts. However, the PAN-based electrolytes undergo severe interfacial problems from both cathode and anode sides, including uneven ionic transfer induced by high rigidity of dry PAN-based polymer, as well as inferior stability against Li-metal anode. Herein, the composition regulation of PAN-based electrolytes is proposed by introducing succinonitrile (SN) plastic crystal and LiNO3 salt for the construction of interfacially stable solid-state lithium batteries. The plastic nature of SN enables the rapid ionic transfer in electrolytes, along with the establishment of conformally interfacial contacts. Meanwhile, a stable solid-electrolyte-interface (SEI) layer consisting of Li3N and LiNO2 is in-situ formed at Li/electrolyte interface, contributing to the inhibition of uncontrol reactions between PAN and Li-metal. Consequently, the resultant Li symmetric cell delivers an extended critical current density of 1.7 mA cm−2 and an outstanding cycling lifespan of 700 h at 0.1 mA cm−2. Moreover, the corresponding solid-state LiNi0.6Co0.2Mn0.2O2/Li full cell shows an initial discharge capacity of 161 mAh/g followed by an outstanding capacity retention of 88.7 % after 100 cycles at 0.1C. This work paves the way for application of PAN-based electrolytes in the field of solid-state batteries by facile composition regulation.

The tightest self-assembled ruthenium metal-organic framework combined with proximity hybridization for ultrasensitive electrochemiluminescence analysis of paraquat.

Metal-organic frameworks (MOFs), as porous materials, have great potential for exploring high-performance electrochemiluminescence (ECL) probes. However, the constrained applicability of MOFs in the realm of ECL biosensing is primarily attributed to their inadequate water stability, which consequently impairs the overall ECL efficiency. Herein, we developed a competitive ECL biosensor based on a novel tightest structural ruthenium-based organic framework emitter combining the proximity hybridization-induced catalytic hairpin assembly (CHA) strategy and the quenching effect between the Ru-MOF and ferrocene for detecting paraquat (PQ). Through a simple hydrothermal synthesis strategy, ruthenium and 2,2'-bipyrimidine (bpm) are head-to-head self-assembled to obtain a novel tightest structural Ru-MOF. Due to the metal-ligand charge-transfer (MLCT) effect between ruthenium and the bpm ligand and the connectivity between the internal chromophore units, the Ru-MOF exhibits strong ECL emissions. Meanwhile, the coordination-driven Ru-MOF utilizes strong metal-organic coordination bonds as building blocks, which effectively solves the problem of serious leakage of chromophores caused by water solubility. The sensitive analysis of PQ is realized in the range of 1 pg/mL to 1 ng/mL with a detection limit of 0.352 pg/mL. The tightest structural Ru-MOF driven by the coordination of ruthenium and bridging ligands (2,2'-bipyrimidine, bpm) provides new horizons for exploring high-performance MOF-based ECL probes for quantitative analysis of biomarkers.

Insight into the electrochemical process of EDTA-assisted soil washing effluent under alternating current

EDTA has been widely utilized as a chelating agent in soil heavy metal remediation, due to its strong coordination capability. Electrochemical deposition is a promising avenue to treat soil washing effluent. However, the impact of advanced electrochemical techniques on EDTA remains incompletely understood. Herein, we present a pioneering approach, utilizing a dual-chamber electrolytic cell and alternating current (AC) power supply. This approach achieves concurrent removal of M-EDTA while efficiently recovering heavy metal and recycling EDTA. Results demonstrate AC displays superior heavy metal removal capability for Cu, Pb, and Cd compare to direct current (DC), with EDTA decomposition mainly occurring in the anolyte. Substituting DC with AC and employing the dual-chamber electrolytic cell significantly enhances EDTA recovery efficiency from 47% to an impressive 96.8%. XPS and Raman spectra reveal an enhanced oxidative surface of the graphite anode under AC, which diminishes the decomposition of EDTA. Long-term experiments validate that this strategy boosts EDTA cyclability to 20 cycles with an outstanding 84% recovery efficiency and negligible electrode corrosion, surpassing the 8 cycles under the traditional strategy. This study innovatively combines cell design and electrochemical techniques, remarkably improving the reusability of EDTA and anode, offering valuable insights for chelate-related applications.

Silver induced chirality controlled spin filtration observed in ss-DNA functionalized with MoS2.

Chiral molecules can exhibit strong spin-orbit coupling, which can result in a large spin polarization. This is due to the fact that the energy levels of the electrons in a chiral molecule are strongly influenced by the chiral structure of the molecule, which can result in the separation of the energy levels for electrons with different spin orientations. We report a controlled spin-selective transmission of electrons through 20 base-paired poly-cytosine molecules functionalized with MoS2 flakes on ITO glass via the quantum mechanical tunneling effect. A reversion in spin polarization was observed after the silver ions interact with poly-cytosine due to the strong coordination of Ag(I) with cytosine-cytosine (C-C) mismatches, indicating the formation of duplex structural motifs, as confirmed by the circular dichroism spectroscopy at room temperature. Manipulating the spin of an electron through such a small molecule merely controlled by special cations could pave the way for major advances in spin-independent charge transport, advanced bioanalytical system design, and related applications.

Regulating core-shell interfacial interaction by oxygen bridging for enhancing electrochemical performance

It is crucial to design core-shell materials with interfacial interaction, which enhances their electrical conductivity, structural stability, and facilitates efficient charge transfer at the interface. In this study, two core-shell electrodes NC-O-PBA (NC: nickel cobalt layered double hydroxides, O-bridged core-shell materials) and LCCH@Ni(OH)2@PBA (LCCH: linear cobalt carbonate hydroxides, PBA: prussian blue analogs) were fabricated via interfacial contrast strategy to investigate the optimization function of oxygen at core-shell interface. Results show that as-prepared NC-O-PBA with high oxygen content creates an ideal condition for the formation of oxygen bridging. Moreover, the NC-O-PBA promotes a strong bond cooperation between core (NiCo-LDH) and shell (NiCo PBAs). The unit in PBAs can partly coordinate with the oxygen (from hydroxyl groups and interlayer ions in LDH), thus forming a strong interfacial coordination bonding between LDH and PBAs (Ni/Co(LDH)-O-CN(PBAs) or Ni/Co(LDH)-O-Ni/Co(PBAs)). Subsequently, NC-O-PBA electrode presents a high capacity of 1040.6 F g−1 at 1 A g−1 and a retention rate of 87.5% at 1500 cycles of 3 A g−1, much higher than LCCH@Ni(OH)2@PBA (462.4 F g−1 and 41.26%). Finally, in-situ Raman results demonstrated the enhanced Faraday redox reaction of NC-O-PBA. This interfacial contrast strategy and oxygen-bridged approach provide a novel idea for the development of high-performance core-shell electrode materials and facilitate deeper insights into mechanism.

In situ Synthesis of Single Layered Metal-Organic Frameworks via Inkjet Printing on a Cellulose Nanofiber Film.

The inkjet printing is a simple method to develop pattern-controlled 2D metal-organic frameworks (MOFs) due to its cost-effectiveness and ease of operation. Despite the sophisticated structures of MOF crystals, the MOF surfaces are easily contaminated by the adsorption of an ink solution, and the printing nozzle can be clogged by the aggregates of MOFs during printing. Unlike the mixture inks of MOFs and a carrier medium, the surface-specific patterning by in situ synthesis provides the film surface with the controlled patterns of an MOF single layer having different morphologies of MOFs without changing the ink cartridges. It enables facile printing due to the low viscosity of inks and escapes the risk of nozzle clogging because MOFs are synthesized at the printed patterns on the substrates. The ion-exchanged cellulose nanofiber (CNF) films form strong coordination with metal ions enhancing the stability of the MOFs on the film surface. It also demonstrates the controlled coverage of the MOFs by the printing pass number and the carboxylate content of CNF and the tunable adsorption of the guest molecules for different loading capacities of the printed patterns.

Fine optimized cation immobilization strategy for enhancing stability and efficiency of perovskite solar cells

The migration and volatilization of cations within organic–inorganic hybrid perovskite (OIPs) materials has been identified as a major issue for irreversibly degrading perovskite solar cells (PSCs), severely limiting their performance and impeding progress toward large-scale applications. To mitigate these problems, an adjustable cation immobilization strategy was proposed for the first time, in which a series of fluorobenzenesulfonamide (FBSA) molecules was introduced into perovskite precursor, a strong coordination bond was formed between the sulfonamide group with the octahedral imperfection caused by iodine vacancy, along with a hydrogen bond formed between the cation and F atom. As a result, the A-site cations were tightly immobilized in the octahedral of perovskite crystal lattice and the uncoordinated Pb2+ defects were effectively eliminated. Besides, the immobilization distance of cation was finely optimized by changing the substitution position of F atoms. Based on the cation-immobilized perovskite film, the efficiency of PSCs was significantly increased from 19.88 % to 22.30 %. Moreover, the unencapsulated PSCs exhibited impressive light and thermal stability, retaining 82 % of the initial efficiency after 720 h illumination at 1-sun, and maintaining nearly 80 % of the initial PCE after heating at 85 °C for 240 h. Thus, the present study offers a promising approach for advancing the commercialization of stable and high-efficiency perovskite solar cells.