One-dimensional coordinated polymers of tetraphenylethene pyridine and copper-iodide for fluorescence detection of nitroaromatic explosives.

The spatial arrangement of molecules plays a crucial role in determining the macroscopic properties of functional materials. Coordinated polymers (CPs) formed by self-assembly of organic isomeric ligands and metals offer unique performance characteristics. In this study, we present the investigation of a one-dimensional CP, named CIT-E, composed of tetraphenylethene pyridine derivative (TPE-2by-2-E) ligands and copper iodide. The resulting CP exhibits a one-dimensional bead chain structure with exceptional thermal and chemical stability. By leveraging the competitive absorption between CIT-E and the explosive analog 2,4-dinitroaniline, we achieve detection of the explosive through changes in the absorption intensity of the excitation light source and subsequent fluorescence response. The CP demonstrates high selectivity and anti-interference ability in detecting 2,4-dinitroaniline in aqueous solution, with a detection linear range of 0.1 to 300 µM and a detection limit of 0.05 µM, surpassing the national third-level emission standard. These findings highlight the potential of CP CIT-E as a promising material for the detection of explosive nitroaromatic compounds.

Efficient fluorescence-enhanced probe for cyanide ions based on a tetraphenylethene pyridine coordinated copper-iodide complex.

An efficient fluorescence-enhanced probe was developed for detecting cyanide ions (CN-) based on a tetraphenylethene coordinated copper-iodide complex (named CIT-Z). The coordination polymers (CPs) prepared were (Z)-1,2-diphenyl-1,2-bis[4-(pyridin-3-ylmethoxy)phenyl]ethene (1Z) and a CuI cluster, where the tetraphenylethylene (TPE) pyridine derivatives acted as organic ligands and the CuI cluster acted as a metal center. The higher-dimensional CIT-Z exhibited a 3-fold-interpenetrating network structure with excellent optical properties and chemical stability. This study also provides insights into the mechanism behind the fluorescence enhancement, which is attributed to the competitive coordination between CN- and the ligands. The probe showed high selectivity and sensitivity towards CN-, with a detection limit of 0.1 µM and good recovery in the real water samples.

Boosting total oxidation of propane over CeO2@Co3O4 nanofiber catalysts prepared by multifluidic coaxial electrospinning with continuous grain boundary and fast lattice oxygen mobility.

A one-dimensional (1D) core-shell of Co-Ce oxide has been prepared by multifluidic coaxial electrospinning method and evaluated for the total oxidation of propane (C3H8). Activity and morphological characterizations show that the CeO2@Co3O4 nanofiber catalyst, of which the core is CeO2 and the shell is Co3O4, exhibits excellent oxidation activity. The exposed Co3O4 grown on the outside of the fibers can rapidly react with C3H8 while CeO2 with high oxygen storage capacity in the inside is conductive to the enhanced oxidation rate. Besides, the continuous grain boundary provides a fast mass transfer channel for lattice oxygen, and rich oxygen vacancies favor the mobility of active oxygen species. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTs) confirms that the CeO2@Co3O4 catalyst have a faster rate of C3H8 adsorption and better oxidation activity with respect to the counterpart using a single-needle electrospinning method. Moreover, the CeO2@Co3O4 catalyst displays excellent thermal stability, and strong resistance against 5 vol% H2O and 5 vol% CO2 at both 300 and 400 °C. Our strategy can give some new insights into morphological engineering to promote active oxygen mobility via the construction of one-dimensional core-shell of metal oxides for catalytic oxidation of VOCs.

Dual carbon decorated germanium-carbon composite as a stable anode for sodium/potassium-ion batteries.

In the present work, we introduce a dual carbon accommodated structure in which germanium nanoparticles are encapsulated into an ordered mesoporous carbon matrix (Ge-CMK) and further coated with an amorphous carbon layer (Ge@C-CMK) through a nano-casting route followed by chemical vapor deposition (CVD) treatment. In the resultant Ge@C-CMK composite, the unique lane-like pore structure that cooperates with the amorphous carbon surface can not only mitigate the volume expansion of germanium particles, but also improve the electrical conductivity of germanium as well as facilitate Na+/K+ diffusion. When employed as the anode of sodium-ion batteries, the Ge@C-CMK electrode exhibits stable capacity as well as long-term cycling stability (a stable capacity of 176 mAh g-1 at 1 A g-1 after 5000 cycles). Furthermore, it also delivers a reversible capacity when used as the anode of potassium-ion batteries. This demonstrates that the Ge@C-CMK electrode possesses promising application potential as an alternative anode in sodium and potassium ion storage applications.

Facile fabrication of a vanadium nitride/carbon fiber composite for half/full sodium-ion and potassium-ion batteries with long-term cycling performance.

Vanadium-based composite anodes have been designed for applications in alkali metal ion batteries, including lithium-ion batteries (LIBs), sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs). However, the problems of inferior long-term cycling stability caused by the large volume change and dissolution of vanadium-based active materials during cycles and slow diffusion for large radii of Na+ and K+ still limit their underlying capability and need to be addressed. In the present work, we initially designed and fabricated a vanadium nitride/carbon fiber (VN/CNF) composite via a facile electrospinning method followed by the ammonization process. The obtained VN/CNF composite anode exhibited excellent half/full sodium and potassium storage performance. When used as an anode material for SIBs, it delivered a high capacity of 403 mA h g-1 at 0.1 A g-1 after 100 cycles and as large as 237 mA h g-1 at 2 A g-1 even after 4000 cycles with negligible capacity fading. More importantly, the VN/CNFs//Na3V2(PO4)3 full cell by coupling the VN/CNF composite anode with the Na3V2(PO4)3 (NVP) cathode also exhibited a desirable capacity of 257 mA h g-1 at 500 mA g-1 after 50 cycles. Besides, when further evaluated as an anode for PIBs, the VN/CNF composite anode achieved a large capacity of 266 mA h g-1 after 200 cycles at 0.1 A g-1 and maintained a stable capacity of 152 mA h g-1 at 1 A g-1 even after 1000 cycles, showing significant long-term cycling stability. This is one of the best performances of vanadium-based anode materials for SIBs and PIBs reported so far.

In situ fabrication of ultrathin few-layered WSe2 anchored on N, P dual-doped carbon by bioreactor for half/full sodium/potassium-ion batteries with ultralong cycling lifespan.

Sodium/potassium-ion batteries (SIBs/PIBs) with high electrochemical performance are promising but there still remain daunting challenges to explore an anode material with appealing cycling stability and rate capability. In addition, the utilization of waste biomass arouses tremendous researches in energy storage applications. Herein, we elaborately coupling ultrathin few-layered WSe2 nanosheets with N, P-doped biochar by utilizing waste chlorella as adsorbent and reactor. It displays a prominent long-term cycling property (265 mAh g-1 at 1 A g-1 up to 1500 cycles) in SIBs, which is the best long-cycle performance ever reported for WSe2. Paired with Na3V2(PO4)3 cathode, full SIBs also exhibit superior capacity of 210 mAh g-1 at 0.5 A g-1 for 120 cycles. Notably, we also report WSe2-based anode material in PIBs, which delivers a high capacity of 333 mAh g-1 at 0.1 A g-1 for 100 cycles and superior cycling lifespan (155 mAh g-1 at 1 A g-1 up to 5300 cycles) as well as excellent rate properties. Additionally, the mechanism of the repeated process of sodiation/desodiation is revealed, by the deep characterization, such as ex-situ XRD/Raman, galvanostatic intermittent titration technique and CV measurements.

Facile Synthesis of Ultra-Small Few-Layer Nanostructured MoSe2 Embedded on N, P Co-Doped Bio-Carbon for High-Performance Half/Full Sodium-Ion and Potassium-Ion Batteries.

Sodium/potassium-ion batteries (SIBs/PIBs) arouse intensive interest on account of the natural abundance of sodium/potassium resources, the competitive cost and appropriate redox potential. Nevertheless, the huge challenge for SIBs/PIBs lies in the scarcity of an anode material with high capacity and stable structure, which are capable of accommodating large-size ions during cycling. Furthermore, using sustainable natural biomass to fabricate electrodes for energy storage applications is a hot topic. Herein, an ultra-small few-layer nanostructured MoSe2 embedded on N, P co-doped bio-carbon is reported, which is synthesized by using chlorella as the adsorbent and precursor. As a consequence, the MoSe2 /NP-C-2 composite represents exceedingly impressive electrochemical performance for both sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs). It displays a promising reversible capacity (523 mAh g-1 at 100 mA g-1 after 100 cycles) and impressive long-term cycling performance (192 mAh g-1 at 5 A g-1 even after 1000 cycles) in SIBs, which are some of the best properties of MoSe2 -based anode materials for SIBs to date. To further probe the great potential applications, full SIBs pairing the MoSe2 /NP-C-2 composite anode with a Na3 V2 (PO4 )3 cathode also exhibits a satisfactory capacity of 215 mAh g-1 at 500 mA g-1 after 100 cycles. Moreover, it also delivers a decent reversible capacity of 131 mAh g-1 at 1 A g-1 even after 250 cycles for PIBs.

Electrospun VSe1.5/CNF composite with excellent performance for alkali metal ion batteries.

Exploring advanced anode materials with excellent electrochemical performance for rechargeable batteries, including lithium-ion batteries (LIBs), sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs), has attracted great attention. However, low electronic conductivity, severe particle agglomeration and lack of effective synthesis methods have still greatly hampered their rapid development. Herein, we initially fabricate a novel VSe1.5/CNF composite through a facile electrospinning method followed by selenization. The electrochemical measurements show that VSe1.5/CNFs can enable the rapid and durable storage of Li+, Na+, and K+ ions. When used as an anode material for LIBs, the VSe1.5/CNF composite delivers a high capacity of 932 mA h g-1 after 400 cycles at a high current density of 1 A g-1. In addition, for SIBs, the VSe1.5/CNF composite manifests a high reversible capacity of 668 mA h g-1 after 50 cycles and an excellent capacity of 265 mA h g-1 at 2 A g-1 even after an ultra-long 6000 cycles. This is one of the best performances of vanadium-based anode materials for SIBs reported so far. Most remarkably, the VSe1.5/CNF composite also demonstrates a satisfactory reversible K+ storage performance. The simple synthetic route and excellent ion storage properties make the VSe1.5/CNF composite a great prospect for application as an anode material for alkali metal ion batteries.

An Sn doped 1T-2H MoS2 few-layer structure embedded in N/P co-doped bio-carbon for high performance sodium-ion batteries.

A facile method for fabricating Sn doped 1T-2H MoS2 embedded in N/P co-doped bio-carbon is developed using natural chlorella as an adsorbent and a nanoreactor. When used as an anode for sodium-ion batteries, it delivers an excellent rate performance (167 mA h g-1 at 15 A g-1), high capacity (533 mA h g-1 after 50 cycles at 0.1 A g-1), and superior long-term cycling stability (320 mA h g-1 after 500 cycles at 1 A g-1) which are attributed to the synergistic effects of few-layer 1T-2H MoS2 moderate Sn doping and the N/P co-doped bio-carbon.

An ultra-small few-layer MoS2-hierarchical porous carbon fiber composite obtained via nanocasting synthesis for sodium-ion battery anodes with excellent long-term cycling performance.

Rational fabrication of anode electrodes for sodium-ion batteries remains a challenge due to the problem of sluggish Na+ diffusion kinetics, large volume expansion etc. Significant efforts, such as fabricating carbon composites and novel nanostructures, have been devoted to the development of anode materials. Herein, an ultra-small few-layer MoS2 nanostructure confined on a hierarchical porous carbon fiber composite was synthesized through the nanocasting route using a novel hierarchical porous carbon fiber as the template. As an anode material, the composite displays outstanding electrochemical performance for sodium-ion batteries. For instance, it delivers high reversible capacities (491 mA h g-1 after 50 cycles at 0.1 A g-1), high rate performance (387 mA h g-1 at 2 A g-1) and long-term cycling stability (234 mA h g-1 at 1 A g-1 after 3000 cycles). Note that it shows one of the best long-term cycling properties reported to date for MoS2-based anode materials for sodium-ion batteries. This regulation strategy may offer new insights into the fabrication of high-performance anode materials for sodium-ion batteries.

Facile synthesis of hierarchical lychee-like Zn3V3O8@C/rGO nanospheres as high-performance anodes for lithium ion batteries.

In the present work, the hierarchical Zn3V3O8@C/rGO composite with a unique lychee-like architecture was fabricated by a simple one-pot ethanol thermal reduction strategy. When used as an anode material, it exhibited outstanding electrochemical performance for lithium-ion batteries (LIBs). For instance, the Zn3V3O8@C/rGO composite delivers high reversible capacities (1012 mAh g-1 at 0.1 A g-1 after 200 cycles) and high rate stability (448 mAh g-1 at 4 A g-1 after 1000 cycles). This outstanding performance can be attributed to the synergistic effect of the diverse structural virtues, effective interface and dual-spatially hybrid carbon network. Significantly, this one-pot simple strategy can be extended to fabricating highly stable and high rate performance of vanadates or other anode materials for LIBs.

Preparation of a Si/SiO2 -Ordered-Mesoporous-Carbon Nanocomposite as an Anode for High-Performance Lithium-Ion and Sodium-Ion Batteries.

In this work, an Si/SiO2 -ordered-mesoporous carbon (Si/SiO2 -OMC) nanocomposite was initially fabricated through a magnesiothermic reduction strategy by using a two-dimensional bicontinuous mesochannel of SiO2 -OMC as a precursor, combined with an NaOH etching process, in which crystal Si/amorphous SiO2 nanoparticles were encapsulated into the OMC matrix. Not only can such unique porous crystal Si/amorphous SiO2 nanoparticles uniformly dispersed in the OMC matrix mitigate the volume change of active materials during the cycling process, but they can also improve electrical conductivity of Si/SiO2 and facilitate the Li+ /Na+ diffusion. When applied as an anode for lithium-ion batteries (LIBs), the Si/SiO2 -OMC composite displayed superior reversible capacity (958 mA h g-1 at 0.2 A g-1 after 100 cycles) and good cycling life (retaining a capacity of 459 mA h g-1 at 2 A g-1 after 1000 cycles). For sodium-ion batteries (SIBs), the composite maintained a high capacity of 423 mA h g-1 after 100 cycles at 0.05 A g-1 and an extremely stable reversible capacity of 190 mA h g-1 was retained even after 500 cycles at 1 A g-1 . This performance is one of the best long-term cycling properties of Si-based SIB anode materials. The Si/SiO2 -OMC composites exhibited great potential as an alternative material for both lithium- and sodium-ion battery anodes.

Encapsulation of Hemin in Metal-Organic Frameworks for Catalyzing the Chemiluminescence Reaction of the H2O2-Luminol System and Detecting Glucose in the Neutral Condition.

Novel metal-organic frameworks (MOFs) based solid catalysts have been synthesized by encapsulating Hemin into the HKUST-1 MOF materials. These have been first applied in the chemiluminescence field with outstanding performance. The functionalized MOFs not only maintain an excellent catalytic activity inheriting from Hemin but also can be cyclically utilized as solid mimic peroxidases in the neutral condition. The synthesized Hemin@HKUST-1 composites have been used to develop practical sensors for H2O2 and glucose with wide response ranges and low detection limits. It was envisioned that catalyst-functionalized MOFs for chemiluminescence sensing would have promising applications in green, selective, and sensitive detection of target analytes in the future.

Fast, sensitive, and selective ion-triggered disassembly and release based on tris(bipyridine)ruthenium(II)-functionalized metal-organic frameworks.

Metal-organic frameworks (MOFs) are microporous materials assembled from metal ions and organic linkers. Recently, many studies have been focused on the syntheses of MOFs with permanent porosity for various applications. However, no attention has been paid to controllable disassembly of MOFs and related applications. In this work, for the first time we synthesized novel tris(bipyridine)ruthenium(II)-functionalized MOFs (i.e., RuMOFs) that could be ion-responsively disassembled and release massive guest materials loaded in the frameworks. The synthesized RuMOFs exhibited much stability in aqueous solutions containing H(+), and many metal ions, but could be selectively and sensitively disassembled by Hg(2+) ions, resulting in the release of large quantities of Ru(bpy)3(2+). The target-responsive release mechanism was investigated and discussed in detail. On the basis of the ion-responsive disassembly and release, an ultrasensitive electrochemiluminescence sensing method for Hg(2+) has been developed with a very low limit of detection (5.3 × 10(-13) M). It was envisioned that the RuMOFs and similar target-responsive functional MOF materials would have promising applications in ultrasensitive and highly selective chemical sensing and even in accurately controllable drug delivering and releasing.

Recyclable fluorescent gold nanocluster membrane for visual sensing of copper(II) ion in aqueous solution.

Recently, metal-selective fluorescent chemosensors have attracted intense attention for their simple and real-time tracking of metal ions in environmental samples. However, most of the existing fluorescent sensors are one-off sensors and thus suffer from large amount of reagent consumption, significant experimental cost and raising the risk of environmental pollution. In this paper, we developed a green (low reagent consumption, low-toxicity reagent use), recyclable, and visual sensor for Cu(2+) in aqueous solution by using a fluorescent gold nanoclusters membrane (FGM) as the sensing unit, basing on our findings on gold nanoclusters (Au NCs) that the bovine serum albumin (BSA)-coated Au NCs exhibit excellent membrane-forming ability under the isoelectric point of BSA, and thus enable us to obtain a new type of sensing membrane (i.e. FGM) by denaturing Au NCs; the fluorescence of FGM can be significantly quenched by Cu(2+) ion, and the quenched fluorescence can be totally recovered by histidine; the as-prepared FGM is very stable and recyclable, which makes it an ideal sensing material.