Latest ArticlesElectrochemistry with antifouling sensing interfaces that effectively resist the adsorption of nonspecific biomolecules provides a powerful mean for the accurate and sensitive detection of disease biomarkers in complex biofluids. However, there are few strategies to acquire a stable and solid antifouling coating on any substrate by a simple way. Herein, a simple one-step assembly method has been adopted to construct phase-transited bovine serum albumin (PTB) antifouling layers. Prior to construction of the antifouling layers, the poly(3,4-ethylenedioxythiophene) (PEDOT) doped with 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (ionic liquid, IL) were firstly electrodeposited on bare electrodes, endowing good conductivity and catalytic capability for the developed sensor. Subsequently, with the assist of tris(2-carboxyethyl)phosphine (TCEP), the disulfide bonds of bovine serum albumin (BSA) were reduced to form PTB, which can be coated on the PEDOT-IL modified electrode to construct an antifouling electrochemical senor (PTB/PEDOT-IL/GCE) for the detection of uric acid (UA) in human serum. The UA sensor demonstrated a good linear range from 1.11 µmol/L to 798.9 µmol/L, with a high sensitivity of 0.556 µA µmol L−1 cm−2. The combination of conducting polymers with one-step assembly of PTB offers a universal and reliable method for the modification of various electrodes to determine target molecules in complex human body fluids.
Template-oriented multi-component synthesis method has been proven to be an exceedingly reasonable and excellent method for the synthesis of giant two-dimensional (2D) and three-dimensional (3D) supramolecules, but designing and constructing heteroleptic and controllable self-assembly without unexpected by-products remains a challenge. Here we report two discrete trefoil-shaped metallacycle S1 and metallacage S2 by heteroleptic self-assembly using one hexaphenylbenzene core ligand and two capping ligands. The 2D trefoil-shaped metallacycle S1 could resemble the emblem of the classic 'Mitsubishi' motif. The use of template-oriented ligand and bent spacer ligand promotes the quantitative formation of the desired 3D trefoil-shaped metallacage S2. The formed metallacage S2 possesses a molecular weight up to 36 kDa, diameter 6.6 nm and height 3.0 nm. All supramolecular coordination complexes were fully characterized by NMR spectroscopy (1H NMR, 2D COSY, 2D NOESY, 2D DOSY), high-resolution electrospray ionization mass spectrometry ESI-MS, ESI-TWIM-MS, TEM and AFM.
Two-dimensional organic-inorganic hybrid ferroelastics with high-temperature reversible phase transitions are very rare and have become one of the research hotspots in the field of ferroelastic materials. Herein, we report three new layered organic-inorganic hybrid perovskites based on halogen-substituted phenethylaminium, (3-XC6H5CH2CH2NH3)2[CdCl4] (X = F (1), Cl (2) and Br (3)). They undergo structural phase transitions at 376/371 K, 436/430 K, and 421/411 K, respectively, between the isomorphic high-temperature phases (space group I4/mmm, Z = 2) and different room-temperature phases with the reduced structural symmetries, i.e., P21/a (Z = 2) in 1, (Z = 4) in 2, and P21/a (Z = 4) in 3, respectively. These ferroelastic transitions arise from the order-disorder transition of organic cations together with the synchronous displacement of inorganic layers, accompanying with ferroelastic spontaneous strains of 0.16, 0.13 and 0.12 for 1−3, respectively. By enriching layered perovskite ferroelastics based on halogen-substituted cations, this work provides important clues for exploring new ferroic materials based on hybrid crystals.
Because of abundant redox activity, broad tunability, and specific atomic structure, polyoxometalates (POMs or POM) clusters have attracted burgeoning interests in electrochemical especially energy storage fields. Nevertheless, due to the high solubility and fully oxidized state, they often suffer from electrically insulation as well as chemical and electrochemical instability. Traditional noncovalent loading or covalent grafting of POMs on conductive substrates have been successfully performed to overcome this problem. However, severe shedding or agglomeration of POMs arising from weak interactions with substrates or excessive entrapment or weak destruction in conductive supports cause significantly reduced availability and stability. To this end, precise confinement of POMs into conductive supports has been tried to improve their dispersibility and stability. Herein, recent progress of POMs from surface loading to precise confinement in the electrochemistry energy storage field is reviewed. Firstly, we illustrate the typical non-confinement methods (viz. covalent and non-covalent) for supported POMs in energy storage applications. Secondly, different strategies for precise confinement of POMs in organic and inorganic materials for related applications are also discussed. Finally, future research directions and opportunities for confined POMs, and derived ultrafine nanostructures are also proposed. This review seeks to point out future research directions of supported POMs in the electrochemistry-related fields.
A photocycloaddition reaction of ethyl 1,4-diaryl-1,4-dihydropyridine-3-carboxylate for the construction of 3,9-diazatetraasteranes (P1) and 3,9-diazatetracyclododecanes (P2) is reported for the first time. The types of reaction product clearly differ with solvent, regardless of the irradiation wavelength. The difference in P1 and P2 lies in the second step of the intramolecular [2 + 2] photocyclization. In order to further investigate this phenomenon and gain a deeper understanding of the photochemical behavior of 1,4-dihydropyridines, DFT and TDDFT theoretical calculations are performed. The results provide a good explanation for the formation of 3,9-diazatetraasteranes and 3,9-diazatetracyclododecanes.
There are some critical issues hindering the practical applications of aqueous zinc-ion batteries (ZIBs), although they possess high safety and low cost as one of promising energy storge devices, such as the Zn dendrite growth and the by-product of Zn4SO4(OH)6·xH2O (ZHS) resulted from some side reactions in a mild electrolyte. Herein, a compact and self-repairing solid electrolyte interface (SEI) film, as labeled the PVDF-Zn(TFSI)2-ZHS coating [The PVDF and Zn(TFSI)2 are polyvinylidene fluoride and zinc bis(trifluoromethanesulfonyl)imide, respectively], which turns the in-situ generated ZHS into a beneficial ingredient onto the pre-coated PVDF-based composite coating layer containing Zn(TFSI)2, was designed and fabricated by a simple doctor blade method. It is shown that the SEI layer can effectively isolate Zn from the electrolyte and homogenize the Zn2+ flux, and thus effectively suppress side reactions and dendrites growth. Benefiting from the hybrid SEI layer, a symmetric cell exhibits a high cycling stability over 750 h at 2.0 mA/cm2 and 2.0 mAh/cm2, and meanwhile, a full-cell, coupled with K+ pre-intercalation α-MnO2 (KMO) cathode, displays excellent rate performance, stable coulombic efficiency and an acceptable cycle life. This work provides a feasible approach for simple and scalable modification of Zn anodes to achieve high performance.
Recognized as one of the important active species involved in various reactions, singlet oxygen (1O2) shows potential applications in chemical, biological, and environmental related fields. However, the controlled capture and release of 1O2 are still facing huge challenges due to its short lifetime and high reactivity. Herein, a framework-interpenetration tuning strategy was applied on a metal-organic framework (MOF) that aiming to improve the capture and release rate of 1O2. The porosity of the MOF was remarkably enhanced with the structural evolution from seven-fold (termed NKM-181) to six-fold interpenetration (termed NKM-182), and the active anthracene sites became much more accessible. Such drastic process can be achieved as simple as exchanging the primitive MOF in selected solvent and occurred surprisingly as single-crystal to single-crystal transformation. Also, additionally owing to the unblocked regular channels, NKM-182 shown significantly improved 1O2 trapping and releasing rates compared to that of in NKM-181. This work demonstrates an unprecedented regulation of 1O2 capture and release process, along with achieving the highest 1O2 capture and release rate among reported porous materials. Furthermore, the obtained endoperoxides with 1O2 loaded (termed EPO-NKM-181 and EPO-NKM-182) can be used as a high efficiency smart material for anti-fake application
Carbon is a promising capacitive electrode material for Zn-ion hybrid supercapacitors (ZHSCs), as it is low-cost, environmentally friendly, controllable and adjustable. By now, achieving both high energy and high power with carbon electrodes is still challenging, limited by their intrinsic properties. In this work, we have designed and presented an amorphous hollow carbon bowl material with surface chemical modifications of oxygen groups to figure out these concerns. The preparation of bowl-like structures and the storage behavior between Zn2+ and oxygen functional groups have also been discussed. With the contributions from its unique hollow structure and surface functional groups, it can significantly enhance the electrode pseudocapacitance and the entire electrochemical performance.
Epoxidation is an important chemical process for the production of epoxides, key building blocks in chemical industry. Despite great efforts being made to facilitate this process, it remains a significant challenge to develop cost-effective, environmental-friendly, and selective catalysts. Herein, we reported a highly dispersed Mn supported by g-C3N4 (Mn/g-C3N4) with Mn loading up to 2.56 wt%. The Mn/g-C3N4 exhibited satisfied catalytic performance for olefin epoxidation with excellent conversion (91%), high selectivity (93%) as well as outstanding recycling stability. Further analysis revealed the importance of Mn-N structure for the generation of active oxo-containing species and subsequent oxygen atom transfer. Besides, an efficient synthesis of cyclic carbonates from styrene epoxide and CO2 has been achieved (88% conversion, 89% selectivity) based on the polar Mn-N coordinated characteristics of Mn/g-C3N4 catalyst.
Poly(m-phthaloyl-m-phenylenediamine) (PMIA) is promising as the separator in lithium-ion batteries (LIBs) for its excellent thermostability, insulation and self-extinguishing properties. However, its low mechanical strength and poor electrolyte affinity limit its application in LIBs. In this work, a new PMIA@polyacrylonitrile-polyvinylidene fluoride hexafluoropropylene-titanium dioxide (PMIA@PAN/PVDF-HFP/TiO2) composite fibrous separator with a coaxial core-shell structure was developed by combining coaxial electrospinning, hot pressing, and heat treatment techniques. This separator not only inherits the exceptional thermostability of PMIA, showing no evident thermal shrinkage at 220 ℃, but also reveals improved mechanical strength (29.7 MPa) due to the formation of firm connections between fibers with the melted PVDF-HFP. Meanwhile, the massive polar groups in PVDF-HFP play a vital role in improving the electrolyte affinity, which renders the separator a high ionic conductivity of 1.36 × 10−3 S/cm. Therefore, the LIBs with PMIA@PAN/PVDF-HFP/TiO2 separators exhibited excellent cycling and rate performance at 25 ℃, and a high capacity retention rate (76.2%) at 80 ℃ for 200 cycles at 1 C. Besides, the lithium metal symmetric battery assembled by the separator showed a small overpotential, indicating that the separator had a role in inhibiting lithium dendrites. In short, the PMIA@PAN/PVDF-HFP/TiO2 separator possesses a wide application prospect in the domain of LIBs.