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A novel hexaazatrinaphthylene-based (HATN) azo polymer (PAH) was synthesized from a newly designed tri-nitro compound trinitrodiquinoxalino[2,3-a:2',3'

In this study, a novel molecularly imprinted electrochemical sensor for p-cresol detection was constructed by combining GO/ZIF-67/AgNPs with molecular imprinting technology.

With the in-depth research of sodium-ion batteries (SIBs), the development of novel sodium-ion anode material has become a top priority. In this work, tube cluster-shaped SbPS4 was synthesized by a high-temperature solid phase reaction. Then the typical short tubular ternary thiophosphate SbPS4 compounded with graphene oxide (SbPS4/GO) was successfully synthesized after ultrasonication and freeze-drying. SbPS4 shows a high theoretical specific capacity (1335 mAh/g) according to the conversion-alloying dual mechanisms. The unique short tube inserted in the spongy graphene structure of SbPS4/GO results in boosting the Na ions transport and alleviating the huge volume change in the charging and discharging processes, improving the sodium storage performance. Consequently, the tubular SbPS4 compounded with 10% GO provides an outstanding capacity of 359.58 mAh/g at 500 mA/g. The result indicates that SbPS4/GO anode has a promising application potential for SIBs.

CoSe-SC@NC as an advanced anode for SIBs have been reported in this work, it exhibits excellent electrochemical performance. Meanwhile, the improved sodium storage mechanism is further analyzed by in situ XRD and ex situ HRTEM.

Graphite as a promising anode candidate of K-ion batteries (KIBs) has been increasingly studied currently, but corresponding rate performance and cycling stability are usually inferior to amorphous carbon materials. To protect the layer structure and further boost performance, tempura-like carbon/carbon nanocomposite of graphite@pitch-derived S-doped carbon (G@PSC) is designed and prepared by a facile and low-temperature modified molten salt method. This robust encapsulation structure makes their respective advantages complementary to each other, showing mutual promotion of electrochemical performances caused by synergy effect. As a result, the G@PSC electrode is applied in KIBs, delivering impressive rate capabilities (465, 408, 370, 332, 290, and 227 mA h g−1 at 0.05, 0.2, 0.5, 1, 2, and 5 A g−1) and ultralong cyclic stability (163 mA g−1 remaining even after 8000 cycles at 2 A g−1). On basis of ex-situ studies, the sectionalized K-storage mechanism with adsorption (pseudocapacitance caused by S doping)-intercalation (pitch-derived carbon and graphite) pattern is revealed. Moreover, the exact insights into remarkable rate performances are taken by electrochemical kinetics tests and density functional theory calculation. In a word, this study adopts a facile method to synthesize high-performance carbon/carbon nanocomposite and is of practical significance for development of carbonaceous anode in KIBs.

Carbon dots (CDs), as a new kind of carbon-based luminescent nanomaterials, have drawn widespread attention in the fields of fluorescence sensing, optoelectronic devices, and biological imaging. This work uses citric acid (CA) and Nile Blue A (NBA) as precursors. By simply changing the solvent in the reaction, their bandgaps were systematically controlled, thereby successfully obtaining bright blue, yellow and red fluorescence emission CDs (B-, Y- and RCDs). The higher quantum yield (QY) of B-, Y- and RCDs are 64%, 57% and 51%, respectively. The selected precursors and different solvents are the key to the formation of three emission CDs. Detailed characterization and density functional theory (DFT) calculations further indicate that the difference in emission color of CDs is due to the size of the sp2 conjugate domain. In addition, we used multicolor CDs as fluorescent probes to investigate their performance in detection. Among them, BCDs and YCDs can detect Sudan Red I with high selectivity and sensitivity. In the concentration range of 0 to 80 µM, the detection limits are 56 and 41 nM, respectively. Multicolor emitting phosphors and fluorescent films are also obtained by mixing CDs with other matrices. Using Ultraviolet (UV) chip as the excitation source and combining with multicolor fluorescent film and a certain proportion of B-, Y-, and RCDs/epoxy resin composites, bright monochromatic light-emitting diodes (LEDs) and white LED (WLED) with high color rendering index (CRI) were prepared. The above results indicate that the multicolor CDs prepared by us have great application potential in the fields of food safety control and optical devices.

The determination of ammonium ions (NH

As a cathode for sodium‐ion batteries (SIBs), Na3V2(PO4)2F3 (NVPF) with 3D open framework is a promising candidate due to its high working voltage and large theoretical capacity. However, the severe capacity degradation and poor rate capability hinder its practical applications. The present study demonstrated the optimization of Na‐storage performance of NVPF via delicate lattice modulation. Aliovalent substitution of V3+ at Na+ in NVPF induces the generation of electronic defects and expansion of Na+‐migration channels, resulting in the enhancement in electronic conductivity and acceleration of Na+‐migration kinetics. It is disclosed that the formed stronger NaO bonds with high ionicity than VO bonds lead to the significant increase in structural stability and ionicity in the Na+‐substituted NVPF (NVPF‐Nax). The aforementioned effects of Na+ substitution achieve the unprecedented electrochemical performance in the optimized Na3.14V1.93Na0.07(PO4)2F3 (NVPF‐Na0.07). As a result, NVPF‐Na0.07 delivers a high‐rate capability (77.5 mAh g−1 at 20 C) and ultralong cycle life (only 0.027% capacity decay per cycle over 1000 cycles at 10 C). Sodium‐ion full cells are designed using NVPF‐Na0.07 as cathode and Se@reduced graphene oxide as anode. The full cells exhibit excellent wide‐temperature electrochemical performance from −25 to 25°C with an outstanding rate capability (96.3 mAh g−1 at 20 C). Furthermore, it delivered an excellent cycling performance over 300 cycles with a capacity retention exceeding 90% at 0.5 C under different temperatures. This study demonstrates a feasible strategy for the development of advanced cathode materials with excellent electrochemical properties to achieve high‐efficiency energy storage.

The direct oxidation of methane to more desirable, one-carbon oxygenated molecules such as methanol and formaldehyde offers a pathway towards a more sustainable chemical industry as the current commercial reforming process involving two steps features a high carbon footprint and energy consumption. Here, we report the selective photocatalytic oxidation of methane at room temperature using quantum-sized bismuth vanadate nanoparticles as the catalyst and oxygen as a mild oxidant. The reaction offers a high selectivity, of 96.6% for methanol or 86.7% for formaldehyde, under optimum wavelength and intensity of light, reaction time and amount of water solvent. Comprehensive characterizations disclose a multistep reaction mechanism in which the activation of methane by the hydroxyl radical determines the reaction rate. This work broadens the avenue towards the selective conversion of the greenhouse gas methane into desirable chemical products in a sustainable way. The conversion of methane to target one-carbon oxygenates relies on a two-step process that is carbon and energy intensive. Direct oxidation offers a sustainable alternative pathway. Here, the authors report on the selective photocatalytic oxidation of methane at room temperature using bismuth vanadate catalyst, realizing high methanol and formaldehyde selectivity.

A new MgH2–PrF3–Al–Ni composite was prepared by ball milling under hydrogen atmosphere. After initial dehydrogenation and rehydrogenation, Pr3Al11, MgF2, PrH3 and Mg2NiH4 nanoparticles formed accompanying the main phase MgH2. The hydrogen absorption-desorption properties were measured by using a Sieverts-type apparatus. The results showed that the MgH2–PrF3–Al–Ni composite improved cycle stability and enhanced hydrogen desorption kinetics. The improvement of hydrogen absorption-desorption properties is ascribed to the synergetic effect of the in situ formed Pr3Al11, MgF2, PrH3 and Mg2NiH4 nanoparticles. This work provides an important inspiration for the improvement of hydrogen storage properties in Mg-based materials.

With the rapid development of electronic technology, the demand for thermal management materials is increasing continuously. Recent years graphene paper is considered as a potential material to replace the traditional graphitized polyimide film. Although the current route to graphene paper can achieve a high thermal conductivity, the extremely high energy consumption in graphitization procedure and severe heavy metal contamination limit the application of graphene paper. Here we develop a high-efficiency, low-energy cost, and inexpensive technology to produce graphene paper in large quantities. Without graphitization, the thermal conductivity of this graphene laminated film can reach 975 W m−1 K−1 when the thickness of film is 65 μm. Based on this easy-operated technology, we have already completed the pilot plant test, attained capacity of 3 kg graphene per reactor in 8 h and 800 mm × 100 m of graphene film each roll which was continuously and macroscopically assembled on our self-made equipment.

Development of efficient and robust electrode materials is significant for sodium-ion batteries (SIBs). Metallic selenides have been widely investigated as a promising anode material based on their relatively high theoretical capacity. However, rapid capacity fading and huge volume changes greatly hinder their practical application. Herein, for the first time, uniform yolk-shell Fe7Se8@C/N nanoboxes (Fe7Se8@C/N NBs) with the Fe7Se8 cores completely embedded by a thin and robust carbon shell are prepared using a strategy of facile etching method combined with selenization for advanced anode materials for SIBs. Benefiting from the unique structural merits, the Fe7Se8@C/N NBs electrodes for Na-ion half cells exhibit high Na-ion storage capacity (385.5 mAh g−1 at 0.1 A g−1) and superior rate performance (316.0 mAh g−1 at 5 A g−1) as well as impressive cyclability with no capacity decay over 1000 cycles. The sodium storage mechanism of Fe7Se8@C/N NBs electrode is systematically studied with the aid of ex-situ X-ray diffraction and transmission electron microscopy. Finally, the assembled full cells coupled with the lab-made high-voltage Na3V2(PO4)2O2F cathode and Fe7Se8@C/N NBs anode materials show superior energy-storage performance.

The introduction of certain structures or functional groups on benzothiazole and its derivatives containing a benzene ring and a thiazole ring can be used to construct benzothiazole fluorescent probes. Based on the mechanism of photoinduced electron transfer, excited-state intramolecular proton transfer (ESIPT), intramolecular charge transfer, aggregation-induced emission, the obtained fluorescent probes can specifically interact with the analyte, thereby changing their luminescence characteristics to achieve the detection of the analyte. Benzothiazole fluorescent probes can be applied to the detection of substances, the analysis of harmful substances and cell imaging. In this paper, the research situation of benzothiazole fluorescent probes in the past 5 years is reviewed, and it is mainly divided into metal ions, anions, small molecules and biological macromolecules according to the types of analytes. In the conclusion, the current challenges and further applications of benzothiazole fluorescent probes are analyzed. Application of detection and analysis of benzothiazole fluorescent probes.

Transition metal oxides have vastly limited practical application as electrode materials for lithium-ion batteries (LIBs) due to their rapid capacity decay. Here, a versatile strategy to mitigate the volume expansion and low conductivity of Fe3 O4 by coating a thin carbon layer on the surface of Fe3 O4 nanosheets (NSs) was employed. Owing to the 2D core-shell structure, the Fe3 O4 @C NSs exhibit significantly improved rate performance and cycle capability compared with bare Fe3 O4 NSs. After 200 cycles, the discharge capacity at 0.5 A g-1 was 963 mA h g-1 (93 % retained). Moreover, the reaction mechanism of lithium storage was studied in detail by ex situ XRD and HRTEM. When coupled with a commercial LiFePO4 cathode, the resulting full cell retains a capacity of 133 mA h g-1 after 100 cycles at 0.1 A g-1 , which demonstrates its superior energy storage performance. This work provides guidance for constructing 2D metal oxide/carbon composites with high performance and low cost for the field of energy storage.

One main challenge for phosphate cathodes in sodium-ion batteries (SIBs) is to increase the working voltage and energy density to promote its practicability. Herein, an advanced Na3V2(PO4)2F3@C cathode is prepared successfully for sodium-ion full cells. It is revealed that, carbon coating can not only enhance the electronic conductivity and electrode kinetics of Na3V2(PO4)2F3@C and inhibit the growth of particles (i.e., shorten the Na+-migration path), but also unexpectedly for the first time adjust the dis-/charging plateaux at different voltage ranges to increase the mean voltage (from 3.59 to 3.71 V) and energy density (from 336.0 to 428.5 Wh kg−1) of phosphate cathode material. As a result, when used as cathode for SIBs, the prepared Na3V2(PO4)2F3@C delivers much improved electrochemical properties in terms of larger specifc capacity (115.9 vs. 93.5 mAh g−1), more outstanding high-rate capability (e.g., 87.3 vs. 60.5 mAh g−1 at 10 C), higher energy density, and better cycling performance, compared to pristine Na3V2(PO4)2F3. Reasons for the enhanced electrochemical properties include ionicity enhancement of lattice induced by carbon coating, improved electrode kinetics and electronic conductivity, and high stability of lattice, which is elucidated clearly through the contrastive characterization and electrochemical studies. Moreover, excellent energy-storage performance in sodium-ion full cells further demonstrate the extremely high possibility of Na3V2(PO4)2F3@C cathode for practical applications.

Cutaneous squamous cell carcinoma (CSCC) is one of the most common non-melanoma skin cancers worldwide. Fatty acid-binding protein 7 (FABP7) has been reported to be involved in the occurrence, development, metastasis and prognosis of various tumors. In addition, downregulated FABP7 expression was demonstrated in cutaneous malignant melanoma in a previous study. Therefore, we speculated that FABP7 may be a biomarker for CSCC diagnosis. The aim of the present study was to determine the molecular mechanism underlying the effects of FABP7 in CSCC, which may provide a new diagnostic biomarker or treatment target for CSCC. Reverse transcription-PCR, western blotting and immunohistochemistry assays were performed to detect the expression levels of FABP7 in CSCC tissues and cells. Overexpression of FABP7 was achieved in A431 and colo-16 cell lines by transfection with an overexpression vector (oeFABP7). Cell proliferation, colony formation, migration and invasion were detected by Cell Counting Kit-8, crystal violet, scratch and Transwell assays, respectively. Following FABP7 overexpression, western blotting was used to determine the expression levels of proliferation-, invasion- and Notch pathway-associated proteins, including Snail, N-cadherin, Twist, matrix metalloproteinase (MMP)-2, MMP-7, Notch 1 and Notch 3. In addition a CSCC model in nude mice was constructed. Immunohistochemistry was used to determine the expression levels of FABP7, Ki67, Notch 1 and Notch 3. It was demonstrated that FABP7 expression levels were significantly reduced in human CSCC tissues and cells compared with normal samples. Overexpression of FABP7 inhibited the proliferation, invasion and migration abilities of A431 and colo-16 cells compared with those in the negative control group. In addition, transfection with oeFABP7 reduced the expression levels of proliferation-, invasion- and Notch pathway-associated proteins compared with those in the negative control group. Overexpression of FABP7 also reduced the growth of CSCC tumors

Here, we developed a wearable electrochemical sensor for pH and K

Thermally reversible self-healing polymer (SHP) electrolyte membranes are obtained by Diels-Alder cycloaddition and electrolyte embedding. The SHP electrolytes membranes are found to display high ionic conductivity, suitable flexibility, remarkable mechanical properties and self-healing ability. The decomposition potential of the SHP electrolyte membrane is about 4.8 V (vs. Li/Li+) and it possesses excellent electrochemical stability, better than that of the commercial PE film which is only stable up to 4.5 V (vs. Li/Li+). TGA results show that the SHP electrolyte membrane is thermally stable up to 280 °C in a nitrogen atmosphere. When the SHP electrolyte membrane is used as a separator in a lithium-ion battery with an LCO-based cathode, the SHP membrane achieved excellent rate capability and stable cycling for over 100 cycles, and the specific discharge capacity could be almost fully recovered after self-healing. Furthermore, the electrolyte membrane exhibits excellent electrochemical performance, suggesting its potential for application in lithium-ion batteries as separator material.

Confined polymerization is an effective method for precise synthesis, which can further control the micro‐nano structure inside the composite material. Polyaniline (PANI)‐based composites are usually prepared by blending and original growth methods. However, due to the strong rigidity and hydrogen bonding of PANI, the content of PANI composites is low and easy to agglomerate. Here, based on confined polymerization, it is reported that polyaniline /polyether ether ketone (PANI/PEEK) film with high PANI content is synthesized in situ by a one‐step method. The micro‐nano structure of the two polymers in the confined space is further explored and it is found that PANI grows in the free volume of the PEEK chain, making the arrangement of the PEEK chain more orderly. Under the best experimental conditions, the prepared 16 µm‐PANI/PEEK film has a dielectric constant of 205.4 (dielectric loss 0.401), the 75 µm‐PANI/PEEK film has a conductivity of 3.01×10−4 S m−1. The prepared PANI/PEEK composite film can be further used as electronic packaging materials, conductive materials, and other fields, which has potential application prospects in anti‐static, electromagnetic shielding materials, corrosion resistance, and other fields., Polyaniline/polyether ether ketone (PANI/PEEK) composite film is successfully synthesized using PEEKt film as a template through confined polymerization. PANI and PEEK are co‐grown in situ by one‐step method, and the micro‐nano structure changes are further investigated. PANI/PEEK film has a significant application effect in high dielectric materials, conductive materials and other fields.

Nitro groups with a strong electron-withdrawing effect can powerfully influence the fluorescence of fluorophores. In this work, through adjusting the nitro group at the HBT fluorophore to construct a phenylhydrazone structure, two probes (HBTN and HBTH) were synthesized to detect OCl-. Consequently, HBTN with the nitro group quenched the fluorescence of HBT and HBTH without the nitro group causing a redshift of the fluorescence, which resulted in enhanced and ratiometric fluorescence signal changes during the detection process. Among them, HBTN shows good ability to selectively detect OCl- in the concentration range of 0-14 μM with the detection limit of 2.06 nM. Based on HBTN, a portable test strip for detecting OCl- was made for the convenient quantification of the OCl- concentration with a spectrophotometer, and exogenous and endogenous OCl- was successfully imaged in cells.

Carbon dots (CDs) are carbon-based quasi-spherical fluorescent nanoparticles with unique physical and chemical properties. Due to their complexity and diversity, CDs are applied in analytics, sensors, bio-imaging and diagnostics. Stabilizing CDs as well as improving their performances can extend their range of applications; it is desirable to combine them in an appropriate solid matrix or prepare solid-state nanocomposites. In this review, a summary of the research of CD nanocomposites is given. Describes the loading methods of CDs on polymers, metals and their compounds, non-metals and their compounds, and metal organic frameworks, which including electrostatic interactions, covalent bonds, non-covalent bonds or hydrogen bonds. In addition, the working mechanism and application of CD nanomaterials are also introduced. The challenges encountered, potential and prospects with CD nanocomposite are discussed at the end of the article.

We designed two stable monolayers of Ca2NOH and Y2C(OH)2 through replacing the anionic electrons with negatively charged hydroxide ions. Calculation results indicate that these two monolayers are dynamic and thermodynamic stable. Ca2NOH is determined as an indirect semiconductor with band gap of 1.51 eV based on hybrid functional calculations, while Y2C(OH)2 possesses a direct band gap of 0.72 eV. Moreover, to investigate the potential applications of Ca2NOH and Y2C(OH)2 monolayers, we studied the adsorption and diffusion performance of Li, Na and Mg atoms on their surfaces. The calculated adsorption energies, differential charge density and Bader charge analysis reveal that Li, Na and Mg atoms could anchor on Ca2NOH and Y2C(OH)2 surfaces. Nudged Elastic band calculation results suggest that the barriers for Li, Na, and Mg diffusion on Ca2NOH surface are 0.79 eV, 0.42 eV and 0.42 eV. While Y2C(OH)2 monolayer exhibits relative low diffusion barriers of 0.60 eV, 0.26 eV and 0.10 eV for Li, Na and Mg, respectively and their corresponding diffusion coefficients are as large as 1.52 × 10−18, 1.52 × 10−12 and 1.52 × 10−8 m2/s. The diffusion barriers and diffusion coefficients. The appropriate adsorption energies, low diffusion barriers and relative large diffusion coefficients of Na/Mg atoms imply that Ca2NOH and Y2C(OH)2 monolayers are promising electrode materials for the corresponding metal-ion batteries. All the results serves to modify, stabilize and understand two dimensional electrides and put their properties into practical use.

The solid-contact ion-selective electrodes (SC-ISEs) are a type of potentiometric analytical device with features of rapid response, online analysis, and miniaturization. The state-of-the-art SC-ISEs are composed of a solid-contact (SC) layer and an ion-selective membrane (ISM) layer with respective functions of ion-to-electron transduction and ion recognition. Two challenges for the SC-ISEs are the water-layer formation at the SC/ISM phase boundary and the leaking of ISM components, which are both originated from the ISM. Herein, we report a type of SC-ISE based on classic Li-ion battery materials as the SC layer without using the ISM for potentiometric lithium-ion sensing. Both LiFePO4- and LiMn2O4-based SC-ISEs display good Li+ sensing properties (sensitivity, selectivity, and stability). The proposed LiFePO4 electrode exhibits comparable sensitivity and a linear range to conventional SC-ISEs with ISM. Owing to the nonexistence of ISM, the LiFePO4 electrode displays high potential stability. Besides, the LiMn2O4 electrode shows a Nernstian response toward Li+ sensing in a human blood serum solution. This work emphasizes the concept of non-ISM-based SC-ISEs for potentiometric ion sensing.

A knowledge of the adsorption and desorption behavior of sorbates on surface adsorptive site (SAS) is the key to optimizing the chemical reactivity of catalysts. However, direct identification of the chemical reactivity of SASs is still a challenge due to the limitations of characterization techniques. Here, we present a new pathway to determine the kinetics of adsorption/desorption on SASs of graphene oxide (GO) based on total internal reflectance fluorescence microscopy. The switching on and off of the fluorescent signal of SAS lit by carbon dots (CDs) was used to trace the adsorption process and desorption process. We find that sodium pyrophosphate (PPi) could increase the adsorption equilibrium of CDs thermodynamically and promote the substrate-assisted desorption pathway kinetically. At the single turnover level, it was disclosed that the species that can promote desorption may also be an adsorption promoter. Such discovery provides significant guidance for improving the chemical reactivity of the heterogeneous catalyst., Graphical abstract, Public summary • The kinetics of adsorption and desorption process were revealed, respectively, by monitoring a fluorogenic process of carbon dots on the surface of graphene oxides at the single turnover level • By regulating the equilibrium of adsorption and desorption, a mechanism for the simultaneous promotion of adsorption and desorption has been discovered • A desorption accelerator could play a satisfactory double action, i.e., adsorption promoter on thermodynamics and desorption promoter on kinetics