A Stable Triazole-Based Covalent Gel for Long-Term Cycling Zn Anode in Zinc-Ion Batteries.

In this work, a functional covalent gel material is developed to resolve the severe dendritic growth and hydrogen evolution reaction toward Zn/electrolyte interface in aqueous zinc-ion batteries (ZIBs). A covalent gel layer with superior durability forms homogeneously on the surface of Zn foil. The covalent gel with triazole functional groups can uniformize the transport of Zn2+ due to the interactions between Zn2+ ions and the triazole groups in the covalent gel. As a consequence, the symmetrical battery with triazole covalent gel maintains stable Zn plating/stripping for over 3000 h at 1 mA cm-2 and 1 mAh cm-2 , and the full cell combined with a V2 O5 cathode operates steadily and continuously for at least 1800 cycles at 5 A g-1 with a capacity retention rate of 67.0%. This work provides a train of thought to develop stable covalent gels for the protection of zinc anode toward high-performance ZIBs.

Tetra-Nuclear Cluster-Based Lanthanide Metal-Organic Frameworks as White Phosphor, Information Encryption, Self-Calibrating Thermometers, and Fe2+ Sensors.

The application of one kind of metal-organic framework (MOF) material used in multiple fields is one of the most interesting research topics. In this work, four new tetra-nuclear cluster-based lanthanide metal-organic frameworks (LnMOFs) [Ln2(BTDB)3(DMA)(phen)]n (Ln = Tb TbMOF, Eu EuMOF, Gd GdMOF, Tb1.830Eu0.170 Tb,EuMOF, 3,5-bis(trifluoromethyl)-4',4″-dicarboxytriphenylamine = H2BTDB, 1,10-phenanthroline = phen) are obtained based on the ligand of H2BTDB that is synthesized in our laboratory, and the precise single-crystal structure of H2BTDB is obtained for the first time. The white phosphor was obtained by facilely hybridizing two components of the orange-yellow emission phosphor of Tb,EuMOF and the blue luminescence material of triphenylamine according to the trichromatic theory. At the same time, TbMOF, EuMOF, Tb,EuMOF, and the white phosphor can be used for information encryption, demonstrating their potential application in the field of anti-counterfeiting. Tb,EuMOF is also a multi-mode and self-calibrating thermometer within a broad temperature range of 110-300 K. Further studies show that EuMOF is a rapid response sensor for Fe2+, with a very low limit of detection of 2.0 nM, which is much lower than the national standards for Fe2+ (GB 5749-2005, 5.357 µM). It can achieve strong anti-interference detection of Fe2+ in actual samples of tap water and lake water. In addition, EuMOF can also be made into an easy-to-use sensing device of test paper for real-time and visual sensing of Fe2+.

Suppression of Vanadium Oxide Dissolution via Cation Metathesis within a Coordination Supramolecular Network for Durable Aqueous Zn-V2 O5 Batteries.

Aqueous zinc metal batteries (ZMBs) are a promising sustainable technology for large-scale energy storage applications. However, the water is often associated with problematic parasitic reactions on both anode and cathode, leading to the low durability and reliability of ZMBs. Here, a multifunctional separator for the Zn-V2 O5 batteries by growing the coordination supramolecular network (CSN:Zn-MBA, MBA = 2-mercaptobenzoic acid) on the conventional non-woven fabrics (NWF) is developed. CSN tends to form a stronger coordination bond as a softer cation, enabling a thermodynamically preferred Zn2+ to VO2 + substitution in the network, leading to the formation of VO2 -MBA interface, that strongly obstructs the VO2 (OH)2 - penetration but simultaneously allows Zn2+ transfer. Moreover, Zn-MBA molecules can adsorb the OTF- and distribute the interfacial Zn2+ homogeneous, which facilitate a dendrite-free Zn deposition. The Zn-V2 O5 cells with Zn-MBA@NWF separator realize high capacity of 567 mAh g-1 at 0.2 A g-1 , and excellent cyclability over 2000 cycles with capacity retention of 82.2% at 5 A g-1 . This work combines the original advantages of the template and new function of metals via cation metathesis within a CSN, provides a new strategy for inhibiting vanadium oxide dissolution.

Visual and Real-Time Monitoring of Cd2+ in Water, Rice, and Rice Soil with Test Paper Based on [2 + 2] Lanthanide Clusters.

Cadmium ions (Cd2+) are highly toxic to animal and human health, especially through the drinking of Cd2+-contaminated water and eating Cd2+-contaminated rice. Therefore, accurate detection of Cd2+ in water, rice, and rice soil is urgent. In this work, two [2 + 2] lanthanide clusters of Tb2Tb2 and Eu2Eu2 were synthesized and characterized in detail. Interestingly, Tb2Tb2 is a rapid sensor for Cd2+ through luminescence "turn-off". Further studies show that Tb2Tb2 is a highly sensitive and selective sensor toward Cd2+ in water, rice supernatants, and rice soil supernatants, with a very short response time of 20 s. The limit of detection (LOD) in the above three real samples is as low as 0.0112, 1.1240, and 0.1124 ppb, respectively, which is lower than the national standards for food safety in China (GB 2762-2022). More interestingly, a portable sensing device of test paper based on Tb2Tb2 is developed with a facile method, which shows visible, highly sensitive, and selective sensing toward Cd2+ in real samples of water, rice supernatants, and rice soil supernatants. Tb2Tb2 and its sensing device of test paper are an on-site analysis sensor for potentially non-expert users, especially for people in remote rural areas.

A Two-Dimensional Porphyrin Coordination Supramolecular Network Cathode for High-Performance Aqueous Dual-Ion Battery.

Iodine has great potential in the energy storage, but high solubility of I3 - has seriously delayed its promotion. Benefited from abundant active sites and the open channel, two-dimensional coordination supramolecular networks (2D CSNs) is considered to be a candidate for the energy storage. Herein, a 2D porphyrin-CSN cathode named Zn-TCPP for aqueous iodine dual-ion battery (DIB) shows an excellent specific capacity of 278 mAh g-1 , and a high energy density of 340 Wh kg-1 at 5 A g-1 , as well as a durable cycle performance of 5000 cycles and a high Coulombic efficiency of 98 %. Molecular orbital theory, UV/VIS, Raman spectroscopy and density functional theory (DFT) calculations reveal charge-transfer interaction between the donor of porphyrin nitrogen and the acceptor of I3 - , and computational fluid dynamics (CFD) simulations demonstrate the contribution of 2D layered network structure of Zn-TCPP to the penetration of I3 - .

Anchoring I3- via Charge-Transfer Interaction by a Coordination Supramolecular Network Cathode for a High-Performance Aqueous Dual-Ion Battery.

Iodine is considered to have broad application prospects in the field of electrochemical energy storage. However, the high solubility of I3- severely hampers its practical application, and the lack of research on the anchoring mechanism of I3- has seriously hindered the development of advanced cathode materials for iodine batteries. Herein, based on the molecular orbital theory, we studied the charge-transfer interaction between the acceptor of I3- with a σ* empty antibonding orbital and the donor of pyrimidine nitrogen with lone-pair electrons, which is proved by the results of UV-vis absorption spectroscopy, Raman spectroscopy, and density functional theory (DFT) calculations. The prepared dual-ion battery (DIB) exhibits a high voltage platform of 1.2 V, a remarkable discharge-specific capacity of up to 207 mAh g-1, and an energy density of 233 Wh kg-1 at a current density of 5 A g-1, as well as outstanding cycle stability (operating stably for 5000 cycles) with a high Coulombic efficiency of 97%, demonstrating excellent electrochemical performance and a promising prospect in stationary energy storage.

Constructing Hydrophobic Interface with Close-Packed Coordination Supramolecular Network for Long-Cycling and Dendrite-Free Zn-Metal Batteries.

Commercialization of aqueous zinc-metal batteries remains unrealistic due to the substantial dendrite growth and side reaction issues on the zinc anodes. It is highly demanded to develop easy-to-handle approaches for constructing stable, dense, as well as homogeneous solid anode/electrolyte interfaces. Herein, the authors construct the zinc anode interface with a close-packed Zn-TSA (TSA = thiosalicylate) coordination supramolecular network through the facile and up-scalable wet-chemical method. The hydrophobic Zn-TSA network can block solvated water and establish a solid-state diffusion barrier to well-distribute the interfacial Zn2+ , thus inhibiting hydrogen evolution and zinc dendrite growth on the anode. Meanwhile, the Zn-TSA network induces the formation of a uniform and stable solid electrolyte interphase composed of multiple inorganic-organic compounds. This denser structure can accommodate and self-heal the crack/degradation of the anode interphase associated with the repeated volume changes, and suppress the generation of detrimental by-product, Znx (OTF- )y (OH)2x-y ·nH2 O. Such a rationally fabricated anode/electrolyte interface further endows the assembled symmetric cells with superior plating/stripping stability for over 2000 h without dendrite formation (at 1 mA cm-2 and 1 mAh cm-2 ). Furthermore, this zinc anode has practical application in the Zn-MoS2 and Zn-V2 O5 full cells. This study provides a new train of thought for constructing the dense interface of zinc-metal anode.

A nano interlayer spacing and rich defect 1T-MoS2 as cathode for superior performance aqueous zinc-ion batteries.

Aqueous Zn-ion batteries (ZIBs) are considered very promising alternatives to lithium-ion batteries. However, the low reversibility and slow diffusion of zinc ions in the positive electrode limit their commercial applications. Herein, we successfully prepared the metallic 1T phase of MoS2 (1T-MoS2) with a nano interlayer spacing of 1.025 nm through a simple one-step hydrothermal method, and used it as a cathode in ZIBs. By adjusting the hydrothermal temperature, the crystallinity and Zn2+ storage capacity of MoS2 as a cathode for ZIBs are effectively improved. MoS2 had the most favorable structure when the hydrothermal temperature was 200 °C, such as larger layer spacing and more lattice distortion. When employed as a cathode, 200-MoS2 exhibited a considerable specific capacity of 125 mA h g-1 at the current density of 2 A g-1 and high capacity retention of 100% after 500 cycles. This strategy provides a new option for improving the performance of the layered structure as an aqueous zinc ion battery.

Luminescent lanthanide metal-organic framework test strip for immediate detection of tetracycline antibiotics in water.

Tetracycline antibiotics (TCs) are a kind of commonly used antibiotics for treating infections, however, the overuse of TCs has adversely affected human health and the ecosystem. Thus, detection of TCs in water is important but challenging. In this work, a luminescent lanthanide metal-organic framework (LnMOF) sensor (1) for immediate detection of oxytetracycline (OTC) and tetracycline (TC) is developed. The sensor has high acid-base and water stability. Investigation reveals that among the 27 species of antibiotics, anions and cations under investigation, 1 shows highly selective sensing towards OTC and TC, and the detection is not disturbed by the presence of other species. The limit of detection (LOD) for OTC and TC are ultra-sensitive value of 1.95 and 2.77 nM, respectively. Investigation reveals the sensing mechanism is due to the inner filter effect. Further studies reveal that the sensor can be used in real sample monitoring. More importantly, test strips based on 1 are manufactured. They are an easy-to-use, low-cost, highly selective and sensitive sensing device for detecting OTC and TC. The sensing can be distinguished immediately and easily by the naked eyes, making it an excellent candidate to monitor OTC and TC in real use.

Mixed matrix membranes incorporated with Ln-MOF for selective and sensitive detection of nitrofuran antibiotics based on inner filter effect.

The detection of antibiotics is critical and challenging due to the pervasive use of antibiotics had inevitably brought some negative impacts on ecosystem and human health. Herein, we reported an anti-interfere ability enhanced luminescent sensor of lanthanide metal-organic framework (Ln-MOF) filled mixed matrix membranes (MMMs), which combining the processibility of poly(methyl methacrylate) (PMMA) polymer with Ln-MOF of {[Tb2(AIP)2(H2O)10]·(AIP)·4H2O}n (Tb-AIP, where AIP is 5-aminoisophthalate) fillers. The as-fabricated Tb-AIP MMMs are stable in water with a wide pH range and exhibit characteristic blue emission of Tb3+. Significantly, the Tb-AIP MMMs show highly selective and sensitive to nitrofuran antibiotics (NFAs) via inner filter effect (IFE), and yet remain unaffected not only by other common antibiotics but also by other types of analytes (metal ions and anions) that may coexist. The limits of detection for nitrofurantoin (NFT) and nitrofurazone (NFZ) are 0.30 and 0.35µM, respectively. As a proof of concept, the proposed MMMs sensor are demonstrated to be feasible for application in detecting NFAs in original water of Pearl River and bovine serum samples, the corresponding quenching constants and limits of detection are similar to their standard detections in an acceptable range. Furthermore, this MMMs sensor for NFAs detection was reversible after washing with deionized water. The luminescent Ln-MOF filled MMMs presented here provides a functional platform for simple yet useful in sensing of NFAs in environment and biology systems.

A Lanthanide MOF Thin-Film Fixed with Co3 O4 Nano-Anchors as a Highly Efficient Luminescent Sensor for Nitrofuran Antibiotics.

Nitrofurans are a group of widely used veterinary antibiotics, which have been banned due to antibiotics pollution. Development of a rapid and effective method for the detection of nitrofuran antibiotics (NFAs) is an important challenge. Herein, we designed a chemical sensor based on a thin-film composed of the lanthanide metal-organic framework (Ln-MOF) {[Eu2 (BCA)3 (H2 O)(DMF)3 ]⋅0.5DMF⋅H2 O}n (Eu-BCA, in which BCA is 2,2'-biquinoline-4,4'-dicarboxylate) coated on a cost-effective stainless steel wire mesh (SSWM) by Co3 O4 nano-anchor fixation method. The MOF coatings were well adhered to the SSWM, resulting in a three-dimensional porous, flexible, and processable sensor. The structure of the as-prepared MOF thin-film was confirmed by powder X-ray diffraction (PXRD), and the surface morphology was examined by scanning electron microscopy (SEM). Significantly, the Eu-BCA thin-film was highly selective and sensitive to NFAs, and yet remained unaffected by other common antibiotics that may be present. The limits of detection for nitrofurantoin (NFT) and nitrofurazone (NFZ) are 0.21 and 0.16 µm, respectively. NFAs were also successfully detected in water from the Pearl River in Guangzhou, and from bovine serum samples. Hence, the reported Ln-MOF thin-film is a promising sensor for the detection of NFAs, thereby helping to protect human beings from all manner of hazards that arise from the abuse of antibiotics in livestock breeding.

A Novel Electrophoretic Deposited Coordination Supramolecular Network Film for Detecting Phosphate and Biophosphate.

A series of new lanthanide coordination supramolecular networks (CSNs) based on nalidixic acid (HNA) ligand were designed and synthesized. Their crystal structures were determined by single-crystal XRD techniques. Thin films of these compounds were first successfully deposited on indium tin oxide (ITO) glass through one-step electrophoretic deposition under mild conditions. The europium CSN film exhibits intense red emission and can act as a highly sensitive luminescent sensor for H2 PO4- anions and adenosine triphosphate (ATP) in aqueous solution. The limits of detection of H2 PO4- and ATP can achieve 0.68 and 1.9 µm respectively. The sensing mechanism was further explored through fluorescence and UV techniques. The fabricated sensor also showed excellent selectivity towards these phosphates in the presence of other coexisting ions (F- , Cl- , Br- , I- , SO4- , CO32- , NO3- , and AcO- ) without interference. Moreover, we demonstrated the feasibility of using this sensor to detect ATP in bovine serum samples, suggesting the potential value of application in real biosystems.

A new luminescent lanthanide supramolecular network possessing free Lewis base sites for highly selective and sensitive Cu(2+) sensing.

A series of new lanthanide complexes, formulated as [Ln2(DCSAL)3(H2O)11]·3DCSAL·4H2O [Ln = Eu (1), Gd (2) and Tb (3); DCSAL = 3,5-dichlorosalicylate], have been synthesized and characterized by single crystal X-ray analysis. They are dinuclear clusters and form a 3D supramolecular network viaπ-π stacking and halogen bonding interactions. 3 exhibits strong Tb characteristic emission, whose quantum yield is as high as 38%. Due to binding with Cu(2+) ions via its Lewis acid-base interactions, 3 displayed a high selectivity and sensitivity for Cu(2+) detection based on Tb(3+) emission quenching. The possible quenching mechanism was further proved to be a static quenching mechanism by Stern-Volmer plots and UV-vis spectrum. More importantly, the binding constant between 3 and Cu(2+) is also calculated by the Benesi-Hildebrand method, which is helpful for quantitative analysis.

A facile fabrication of electrodeposited luminescent MOF thin films for selective and recyclable sensing of nitroaromatic explosives.

Rapid detection of nitroaromatic explosives is of utmost importance from the perspectives of civilian safety, the natural environment and human health. Herein, we design a simple yet powerful optical sensing motif based on an electrodeposited luminescent MOF thin film of {[Eu2(TDC)3(CH3OH)2]·CH3OH} (Eu-TDC, where TDC is thiophene-2,5-dicarboxylate). The parameters of the electrodeposition process were investigated and optimized. The phase and elemental composition of the Eu-TDC film were confirmed using powder X-ray diffraction (PXRD) and energy dispersive spectrometry (EDS), and its morphology and structure were examined using scanning electron microscopy (SEM). This thin film shows extremely good luminescence properties with characteristics of Eu(3+) that are sensitized by the electron-rich ligands, which allows for high efficiency in electron-deficient nitroaromatic explosive sensing. Selective and sensitive responses to a series of nitroaromatic explosives were exhibited, especially for nitrophenols (TNP/DNP/4-NP, KSV > 10(4) M(-1)). It is also an efficient luminescent sensor for detecting nitrobenzene vapour. Significantly, this film can be easily recycled just by washing with methanol. The potential sensing mechanisms are discussed in detail.

Titanium dioxide@polypyrrole core-shell nanowires for all solid-state flexible supercapacitors.

Herein, we developed a facile two-step process to synthesize TiO2@PPy core-shell nanowires (NWs) on carbon cloth and reported their improved electrochemical performance for flexible supercapacitors (SCs). The fabricated solid-state SC device based on TiO2@PPy core-shell NWs not only has excellent flexibility, but also exhibits remarkable electrochemical performance.

A highly luminescent terbium-organic framework for reversible detection of mercury ions in aqueous solution.

A new organic-lanthanide framework [TbL1.5(H2O)2]·H2O (1) [H2L = 5-(3'-carboxylphenyl)nicotinic acid] was synthesized. Its structure was determined by single crystal X-ray diffraction. The complex was characterized by PXRD, FT-IR, fluorescence as well as TGA, and features a 3D framework with a 1D channel and exhibits exceptionally high thermal stability up to 440 °C in air. Furthermore, it displays highly sensitive and selective luminescence quenching to Hg(2+) in aqueous solution. The result of a reversible sensing experiment showed complex 1 could be reusable at least 5 times.

Unusual method for phenolic hydroxyl bridged lanthanide CPs: syntheses, characterization, one and two photon luminescence.

A "basophilic method" for phenolic hydroxyl bridged lanthanide coordination polymers (CPs) was developed. With this method, eleven CPs with the general formula of [Ln(HL1)L1·H(2)O](n) (Ln = Tb (1), Nd (2), Eu (3), Gd (4), La (5), Er (6), Y (7), H(2)L1 = 4-methyl salicylic acid) and [Ln(HL2)L2·2MeOH](n) (Ln = Eu (8), Tb (9), Gd (10), La (11), H(2)L2 = 3-hydroxy-2-naphthoic acid) were synthesized based on two ligands, and five of them (1-4 and 8) were characterised by X-ray single crystal diffraction. The powder X-ray diffraction patterns (PXRD) of complexes showed that 1-7 are isostructural, 8-11 are isostructural. Furthermore, 1 was characterised by Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), differential thermal analysis (DTA), elemental analysis (EA), one and two photon luminescence were investigated in detail.

2,4,6-Tris(2,4-dimethyl-phen-yl)-1,3,5-triazine.

Two virtually superimposable mol-ecules comprise the asymmetric unit of the title compound, C(27)H(27)N(3). The range of dihedral angles between the central 1,3,5-triazine ring and the attached benzene rings is 20.88 (14)-31.36 (14)°, and the shape of each mol-ecule is of a flattened bowl. The crystal packing features weak C-H⋯π bonds and π-π inter-actions between triazine and benzene rings [centroid-centroid separations = 3.7696 (17) and 3.7800 (18) Å] that result in the formation of supra-molecular layers in the ac plane. The crystal studied was a non-merohedral twin with a minor twin component of 20.7 (3)%.

A new luminescent terbium 4-methylsalicylate complex as a novel sensor for detecting the purity of methanol.

A new dinuclear terbium complex [Tb(2)(4-msal)(6)(H(2)O)(4)]·6H(2)O (1) (4-msal = 4-methylsalcylate) was synthesized. Its structure was determined by single crystal X-ray diffraction, and the complex was characterized by PXRD, FT-IR, fluorescence, TGA and DTA. Complex 1 exists as discrete molecules that are linked by extensive O-H … O hydrogen bonds into a 3D network. The luminescence lifetimes of 3 µM methanol solution and solid sample of 1 are 1.321 and 1.009 ms, respectively. The quantum yield of solid sample is 6.0%. The luminescence quenched more than 50% when 3% (vol/vol) different impurities (acetone, acetonitrile, chloroform, dichloromethane, dioxane, DMF, DMSO, ethanol, ether, ethyl acetate, glycol, H(2)O, hexane, TEA, THF and toluene or their mixture) were added. The inverse linear relationship between the Lg value of fluorescence intensity and the volume ratio of the minor component (to a maximum of 20%) is interpreted in terms of LgI = a-bX (I: luminescence intensity; X: volume ratio of impurities in methanol; a, b are constants). So 1 is a potential luminescent sensor for analyzing the purity of methanol.

A versatile Tb(III) complex for picosecond filamentation, a transparent thin film and a supramolecular gel.

The first complex picosecond filament, namely a filament of terbium(III) p-hydroxybenzoate, is observed. The filament is the only example of Ln(III) ion two-photon absorption in a complex. A transparent, colorless and mechanically robust thin film, as well as a supramolecular gel, of this complex are prepared in a facile manner and exhibit strong luminescence. The thin film is characterized in detail by XRD, SEM, UV-vis, luminescence spectroscopy and lifetime.