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Rapid and accurate eddy-current calculation is necessary to analyze eddy-current couplings (ECCs). This paper presents a general 3D analytical method for calculating the magnetic field distributions, eddy currents, and torques of ECCs with different Halbach magnet arrays. By using Fourier decomposition, the magnetization components of Halbach magnet arrays are determined. Then, with a group of H-formulations in the conductor region and Laplacian equations with magnetic scalar potential in the others, analytical magnetic field distributions are predicted and verified by 3D finite element models. Based on Ohm's law for moving conductors, eddy-current distributions and torques are obtained at different speeds. Finally, the Halbach magnet arrays with different segments are optimized to enhance the fundamental amplitude and reduce the harmonic contents of air-gap flux densities. The proposed method shows its correctness and validation in analyzing and optimizing ECCs with Halbach magnet arrays. [ABSTRACT FROM AUTHOR]

Organic contamination of water results in significant risks to the biosphere and human health. The treatment of organic pollutants found in effluents urgently requires a green, sustainable, and effective approach. Herein, a straightforward one-step procedure was developed to create a photocatalytic mesh using iron mesh as the substrate and the g-C3N4/MIL-101(Fe) heterostructure as the photocatalytic material to activate persulfate (PS) for the removal of methyl orange (MO) from water. Fluorescence stereo microscopy (FSM), scanning electron microscopy (SEM), nitrogen adsorption–desorption, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) spectroscopy, and X-ray powder diffraction (XRD) were used to characterize the morphological and physicochemical properties of the synthesized composites, which confirmed the successful growth of g-C3N4/MIL-101(Fe) on the iron mesh. The outstanding PS activation capacity of g-C3N4/MIL-101(Fe) promoted electron transfer and accelerated the generation of SO4˙−, resulting in up to 91.05% MO degradation under 60 min of visible light exposure. The removal mechanisms were investigated by quenching experiments and electron spin resonance (ESR), which proved that ˙OH, ˙O2− and h+ contributed to the removal of MO. Moreover, the degradation pathways of MO and the as-formed intermediates were identified by high-resolution mass spectroscopy (HRMS). This study provides a convenient and economical method to build innovative photocatalytic systems for organic pollutant degradation. [ABSTRACT FROM AUTHOR]

Efficient activation of hydrogen peroxide (H2O2) through biomimetic catalysis still faces a major challenge. In this work, inspired by the catalytic pocket of natural peroxidase, Cu single atom (CuSA) and AuCu nanoparticles (AuCuNPs) anchored on nitrogen‐doped carbon skeleton (CuSA‐AuCuNPs/NC) serve as dual active sites that significantly accelerate the charge transfer process and thus achieve efficient H2O2 activation. Meanwhile, the experimental and theoretical calculations show that the well‐established electronic communication effect between CuSA and AuCuNPs results in moderate electronic modifications to CuSA, which promotes the heterolysis of H2O2 and the timely desorption of H2O. As a proof of concept, CuSA‐AuCuNPs/NC show remarkable performance in detecting uranyl ions in seawater. This work provides new insights into the H2O2 activation for colorimetric sensing. [ABSTRACT FROM AUTHOR]

ZnO quantum dots (QDs) supported on porous nitrogen-doped carbon (ZnOQDs/P-NC) exhibited excellent electrochemical performance for the electroreduction of CO2 to CO with a faradaic efficiency of 95.3% and a current density of 21.6 mA cm−2 at −2.2 V vs. Ag/Ag+. [ABSTRACT FROM AUTHOR]

A rapid and highly selective naked-eye detection of hydrochloric acid (HCl) in an aqueous medium was established using HCl-triggered redispersion of gold nanoparticle aggregates. [ABSTRACT FROM AUTHOR]

The triazine‐based covalent organic frameworks (tCOF), an intriguing subtype of COFs, are expected as highly promising photocatalysts for various photocatalytic applications owing to their fully conjugated structures and nitrogen‐rich skeletons. However, the inherent hydrophobicity and fast recombination of photoexcited electron‐hole pairs are two main factors hindering the application of tCOF in practical photocatalytic reactions. Here, a post‐synthetic modification strategy to fabricate superhydrophilic tCOF‐based photocatalysts is demonstrated by in situ growing FeOOH clusters on TaTz COF (TaTz‐FeOOH) for efficient photocatalytic oxidation of various organic pollutants. The strong polar FeOOH endows TaTz‐FeOOH with good hydrophilic properties. The well‐defined heterogeneous interface between FeOOH and TaTz allows the photoelectrons generated by TaTz to be consumed by Fe (III) to transform into Fe (II), synergistically promoting the separation of holes and the generation of free radicals. Compared with the unmodified TaTz, the optimized TaTz‐FeOOH (1%) shows excellent photocatalytic performance, where the photocatalytic degrade rate (k) of rhodamine B is increased by about 12 times, and the degradation rate is maintained at 99% after 5 cycles, thus achieving efficient removal of quinolone antibiotics from water. This study provides a new avenue for the development of COF‐based hydrophilic functional materials for a wide range of practical applications. [ABSTRACT FROM AUTHOR]

The precisely modulated synthesis of programmable light‐emitting materials remains a challenge. To address this challenge, we construct four tetraphenylethylene‐based supramolecular architectures (SA, SB, SC, and SD), revealing that they exhibit higher electrochemiluminescence (ECL) intensities and efficiencies than the tetraphenylethylene monomer and can be classified as highly efficient and precisely modulated intramolecular aggregation–induced electrochemiluminescence (PI‐AIECL) systems. The best‐performing system (SD) shows a high ECL cathodic efficiency exceeding that of the benchmark tris(2,2′‐bipyridyl)ruthenium(II) chloride in aqueous solution by nearly six‐fold. The electrochemical characterization of these architectures in an organic solvent provides deeper mechanistic insights, revealing that SD features the lowest electrochemical band gap. Density functional theory calculations indicate that the band gap of the guest ligand in the SD structure is the smallest and most closely matched to that of the host scaffold. Finally, the SD system is used to realize ECL‐based cysteine detection (detection limit=14.4 nM) in real samples. Thus, this study not only provides a precisely modulated supramolecular strategy allowing chromophores to be controllably regulated on a molecular scale, but also inspires the programmable synthesis of high‐performance aggregation‐induced electrochemiluminescence emitters. [ABSTRACT FROM AUTHOR]

The precisely modulated synthesis of programmable light‐emitting materials remains a challenge. To address this challenge, we construct four tetraphenylethylene‐based supramolecular architectures (SA, SB, SC, and SD), revealing that they exhibit higher electrochemiluminescence (ECL) intensities and efficiencies than the tetraphenylethylene monomer and can be classified as highly efficient and precisely modulated intramolecular aggregation–induced electrochemiluminescence (PI‐AIECL) systems. The best‐performing system (SD) shows a high ECL cathodic efficiency exceeding that of the benchmark tris(2,2′‐bipyridyl)ruthenium(II) chloride in aqueous solution by nearly six‐fold. The electrochemical characterization of these architectures in an organic solvent provides deeper mechanistic insights, revealing that SD features the lowest electrochemical band gap. Density functional theory calculations indicate that the band gap of the guest ligand in the SD structure is the smallest and most closely matched to that of the host scaffold. Finally, the SD system is used to realize ECL‐based cysteine detection (detection limit=14.4 nM) in real samples. Thus, this study not only provides a precisely modulated supramolecular strategy allowing chromophores to be controllably regulated on a molecular scale, but also inspires the programmable synthesis of high‐performance aggregation‐induced electrochemiluminescence emitters. [ABSTRACT FROM AUTHOR]

BV/In 2 O 3 /FeNi photoanode was rational designed and constructed by impregnation annealing and electrodeposition method. A stable photocurrent of 4.0 mA cm−2 was achieved at 1.23 V RHE under AM 1.5 G (100 mW cm−2), which can be ascribed to the synergistic effect of heterojunction structure and cocatalyst loading. [Display omitted] Bismuth vanadate (BiVO 4) is a promising nanomaterial for photoelectrochemical (PEC) water oxidation. However, the serious charge recombination and sluggish water oxidation kinetics limit its performance. Herein, an integrated photoanode was successfully constructed by modifying BiVO 4 (BV) with In 2 O 3 (In) layer and further decorating amorphous FeNi hydroxides (FeNi). The BV/In/FeNi photoanode exhibited a remarkable photocurrent density of 4.0 mA cm−2 at 1.23 V RHE , which is approximately 3.6 times larger than that of pure BV. And the water oxidation reaction kinetics has an over 200% increased. This improvement was mainly because the formation of BV/In heterojunction inhibited charge recombination, and the decoration of cocatalyst FeNi facilitated the water oxidation reaction kinetics and accelerated hole transfer to electrolyte. Our work provides another possible route to develop high-efficiency photoanodes for practical applications in solar conversion. [ABSTRACT FROM AUTHOR]

Bismuth vanadate (BiVO4) has been considered a promising photoactive material in photoelectrochemical (PEC) water-splitting systems. However, the performance of BiVO4-based photoanodes is currently unsatisfactory, indicating the need for new architectural designs to improve their efficiency. In this paper, a porphyrin-phosphazene polymer (THPP-HCCP) was synthesized with a sizeable conjugated structure, and Ag particles were deposited on its surface as an organic–inorganic composite interface improvement layer. The deposition of the composite polymer film on BiVO4 resulted in a significant increase in photocurrent density, reaching up to 2.2 mA cm−2 (1.23 V vs. RHE), almost three times higher than pristine BiVO4, which benefits from the synergistic effect of Ag nanoparticles and porphyrin-phosphazene. Furthermore, photophysical and intensity-modulated photocurrent analysis demonstrated that the Ag–THPP-HCCP heterostructures could broaden the light-absorbing range and facilitate hole transfer to the semiconductor surface, resulting in an improved water oxidation process. The dynamic charge transport behavior of Ag–THPP-HCCP/BiVO4 was investigated using scanning photoelectrochemical microscopy, which showed that the rate constant (Keff) exhibits an almost 4-fold increase compared to pristine BiVO4, indicating a significant improvement in the transport of photogenerated holes. This experiment presents a novel strategy for designing high-efficiency polymer-based photoanodes. [ABSTRACT FROM AUTHOR]

A novel and tunable synthesis of Fe/CuOx bimetallic catalysts has been achieved via a simple Fe-precipitation and calcination method, which was used for highly efficient CO2 electroreduction to control the wide-ranging CO to H2 ratio by simply changing the ratio of metals. The faradaic efficiency of CO could reach 86.1% with a current density of 49.1 mA cm−2. The ratio of CO/H2 could reach 1.94 to 6.18 and it was discovered that the Fe/CuOx bimetallic catalysts could easily get different ratios of syngas, which can be applied directly in industry. [ABSTRACT FROM AUTHOR]

The electrochemical nitrogen reduction reaction (NRR) has the potential to replace the Haber–Bosch process for ammonia synthesis under ambient conditions. However, the selectivity and yield of the NRR are impractical, owing to the preferential binding of the electrocatalyst to H and the consequential coverage of active sites. In this study, VO2, with N2 strongly adsorbed over H atoms, is used as a support to provide a N2 source to avoid the hydrogen evolution reaction. Mo, with a high NRR activity, is introduced as the active site to promote the NRR. Meanwhile, the electronic metal–support interaction between the support and Mo creates electron‐deficient sites, which weakens H adsorption and lowers the energy barrier of the first step, protonation, thereby kinetically enhancing the NRR activity. The average NH3 yield of Mo/VO2 is 190.1 µgNH3 mgcat.−1 h−1 and the Faradaic efficiency is 32.4% at −0.5 V versus reversible hydrogen electrode, which is 10.8 and 2.8 times greater than that of VO2, respectively. [ABSTRACT FROM AUTHOR]

In this study, a carboxylated carbon nanotube-grafted Ag3PO4@AgIO4 (CNT-COO−/Ag3PO4@AgIO4) composite was synthesized through an in situ electrostatic deposition method. The synthesized composite was characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS), and energy-dispersive X-ray spectroscopy (EDS). The electron transfer ability of the synthesized composite was studied using electrochemical impedance spectroscopy (EIS). The CNT-COO−/Ag3PO4@AgIO4 composite exhibited higher activity than CNT/Ag3PO4@AgIO4, Ag3PO4@AgIO4, and bare Ag3PO4. The material characterization and the detailed study of the various parameters thataffect the photocatalytic reaction revealed that the enhanced catalytic activity is related to the good interfacial interaction between CNT-COO and Ag3PO4. The energy band structure analysis is further considered as a reason for multi-electron reaction enhancement. The results and discussion in this study provide important information for the use of the functionalized CNT-COOH in the field of photocatalysis. Moreover, providinga new way to functionalize CNT viadifferent functional groups may lead to further development in the field of photocatalysis. This work could provide a new way to use natural sunlight to facilitate the practical application of photocatalysts toenvironmental issues. [ABSTRACT FROM AUTHOR]

Fiber‐based electronics technology has been making significant strides towards applicable emergence into many fields. One such field is the use of fiber‐based electronics in the development of smart textiles. Here, we report the use of stretchable styrene‐ethylene‐butylene‐styrene (SEBS) fibers as a conductive substrate to simultaneously load Au nanowire and Prussian blue (PB) as biosensing interfaces. Accordingly, due to the synergistic catalytic effect between Au nanowire and Prussian blue, the as‐obtained flexible PB/Au fibers can not only show the potential as wearable biosensors but also serve as high‐performance peroxidase‐like nanozymes. The functional fibers can be used for colorimetric detection of H2O2 and uric acid, exhibiting satisfactory sensitivity and selectivity in serum sample analysis. The flexible PB/Au fibers represent a new form of Peroxidase‐like nanozymes, which could open doors to various wearable biosensing applications. [ABSTRACT FROM AUTHOR]

Tyrosine is the precursor of some neurotransmitters such as thyroxine and dopamine. It has the effect of regulating emotions and stimulating the nervous system. Changes in tyrosine levels in the human body are associated with certain diseases. Therefore, it is very necessary to prepare a new type of tyrosine sensor. In this work, an enzyme-free electrochemical sensor based on MXene/CNTs/CuMOF composite was developed for the detection of tyrosine. Embedding carbon nanotubes (CNTs) into MXene effectively prevented the aggregation of MXene sheets. Further modification of MXene/CNTs materials with CuMOF octahedral particles with porous structure can improve the porosity and catalytic capability of the composites. Under the optimal detection conditions, the prepared sensor has good linearity in the detection of tyrosine within range 0.53 μM–232.46 μM with a limit of detection (LOD) of 0.19 μM. The stability and selectivity of the sensor is high, and can be used to detect tyrosine in human serum. [Display omitted] [ABSTRACT FROM AUTHOR]

The rapid advancement of science and technology has led to the development of electronic devices that require higher energy storage capacities. Because of their greater energy as well as power density capabilities, hybrid supercapacitors offer an answer to the problems that result from the limitations of both supercapacitors and batteries when it comes to power densities and energy density. Borate ion-functionalized nickel manganese hydroxide nanoparticles (denoted as NiMnB) were prepared by a simple chemical reduction method, and novel complexes were obtained by growing NiMnB with a core-shell structure on reduced graphene oxide (rGO). The NiMnB inner core facilitates electron transport, while the borate/metal borate shell layer on the outer layer aids in OH- absorption. Additionally, rGO integrates the dispersed nanoparticles, resulting in a comprehensive conductive system. This design optimizes the electrochemical performance of NiMn-based electrodes. The specific capacitance of the NiMnB/rGO-16 electrode was 916 F g−1 when tested at a current density of 1 A g−1. NiMnB/rGO-16 was used as the positive electrode and activated carbon (AC) as the negative electrode assembled the hybrid supercapacitor. It showed strong cycling stability and an energy density of 50.2 Wh kg−1. [Display omitted] • Electrode materials with core-shell morphology (NiMnB/rGO) were successfully prepared by chemical reduction method. • NiMnB/rGO-16 electrode shows high specific capacitance of 916 Fg−1 at a current density of 1 A g−1. • The NiMnB/rGO-16//AC device exhibits a high energy density of 800.4 Wkg−1,50.2 Wh kg−1. • NiMnB/rGO-16//AC maintains 86.3 % of initial capacitance after 8000 cycles at 5 A g−1. [ABSTRACT FROM AUTHOR]

• A metal-free graphitized carbon nitride (g-C 3 N 4) nanosheets was synthesized by gas template method. • The surface area and photocurrent of nanosheets was 6 and 3 times than that of bulk g-C 3 N 4 , respectively. • The nanosheets showed superior photodegradation ability towards cefixime. • 99% of cefixime could be removed within 30 min under the sunlight and persulfate addition. The removal and the treatment of antibiotics in environmental water by advanced oxidation process (AOP) has attracted much attention. In this paper, a metal-free graphitized carbon nitride nanosheets (g-C 3 N 4 -NS) was synthesized by gas template method. Cefixime in water was removed by direct photocatalysis and activation of persulfate (PS) under simulated sunlight. The flaky morphology made g-C 3 N 4 -NS's band gap narrow, charge separation enhanced, light absorption enhanced, and more active sites were exposed. The specific surface area of g-C 3 N 4 -NS was about 6 times than that of bulk g-C 3 N 4 , and its photocurrent was about 3 times. The effects of different PS concentrations and pH values on photocatalytic activation in two ways were studied. The influence of anions on the removal of cefixime was also studied. The synthesized g-C 3 N 4 -NS has good stability, and its performance is well maintained after continuous photocatalysis and photoactivation catalysis. The degradation rate of cefixime by g-C 3 N 4 -NS was three times than that of bulk g-C 3 N 4 , and the removal rate of cefixime by g-C 3 N 4 -NS /PS system was 30 times than that of PS. This work provides advanced idea for metal-free AOP in environmental chemistry. [ABSTRACT FROM AUTHOR]

Heavy metal contamination in water and soil are harmful and destructive to the environment, it has always been regarded as a big problem. Herein, we developed a self-healing fluorescent hydrogel based on oxidized carboxymethyl cellulose with excellent sensing and adsorption abilities for Ag+. The detection and adsorption effects of hydrogels on heavy metal ions were studied. It turned out that the fluorescent hydrogel has sensitive detection and high adsorption capacity for Ag+, the detection limit was 3.798 μM, and the maximum adsorption capacity was 407 mg/g. The adsorption isotherm fitted the Langmuir model well, and the pseudo-secondary model for adsorption kinetics fitted well. The hydrogel could heal itself without external stimulus, it could be easily regenerated 7 times without loss of adsorption performance. In short, the prepared hydrogel has capability of self-healing, detecting and adsorbing heavy metal ions at the same time, good mechanical strength, these all made it a promising long-life adsorbent and provided a new way for wastewater treatment. [Display omitted] • The self-healing hydrogel can recover spontaneously when damaged. • The B-doped carbon dots wrapped in the hydrogel make it selective for silver ions and get high detection sensitivity. • Heavy metals can be quickly and efficiently adsorbed by the hydrogel. • The double network structure of the hydrogel makes it exhibit good mechanical properties. [ABSTRACT FROM AUTHOR]

[Display omitted] • A smart strategy, interface "repairing", was proposed to effectively boost the photogenerated charge separation. • BV/NiO x /CoFe achieves a remarkably photocurrent density of 4.58 mA cm−2 at 1.23 V RHE , which is more than three-fold higher than BV photoanode. • The interface charge recombination and intrinsic photocorrosion can be efficiently suppressed through "fast" hole transfer kinetics. Photoelectrochemical (PEC) water splitting is an attractive strategy to convert and store of intermittent solar power into fuel energy. However, the detrimental charge recombination of photogenerated electrons and holes severely limits its efficiency. Despite electrocatalyst loading can obviously improve the PEC conversion efficiency, current systems still suffer from high recombination owing to the surface states. Herein, an interface "repairing" strategy is proposed to suppress the recombination at the semiconductor/electrocatalyst interface. NiO x layer acts as an interfacial repairing layer to efficiently extract photogenerated charge carriers and eliminate the surface states via high hole-transfer kinetics rather than as a traditional electrocatalyst. As expected, the resulting repaired system yields an impressive photocurrent density of 4.58 mA cm−2 at 1.23 V (vs. RHE), corresponding to a more than three-fold increase compared to BiVO 4 (1.40 mA cm−2). Our work offers an appealing maneuver to improve the water oxidation performance for the semiconductor/electrocatalyst coupling system. [ABSTRACT FROM AUTHOR]

Dual‐band electrochromism is a phenomenon where materials can independently regulate the transmittance of visible (VIS) and near‐infrared (NIR) light. Owing to their bistability, low energy consumption, and independent control over VIS and NIR regions, dual‐band electrochromic (EC) devices have been of great significance to fully harnessing VIS and NIR light and building an energy‐saving society. The past several years have witnessed the efforts put in developing novel EC materials to improve their dual‐band optical performance through altering their composition, structural, and physicochemical features, which determine the optical behavior of dual‐band EC devices. In this review, the concept, significance, working principle, and key influence factors of dual‐band electrochromism are briefly introduced. Next, the up‐to‐date progress of dual‐band EC materials including inorganic, organic, and composites materials are summarized, with a focus on material design, device fabrication, and performance optimization. Finally, the challenges and perspectives of dual‐band EC materials and devices are also presented. [ABSTRACT FROM AUTHOR]

β‐CD‐NH2‐Fe3O4 magnetic nanomaterials were prepared and the electrochemical sensor was constructed using β‐CD‐NH2‐Fe3O4 magnetic nanomaterials modified GCE to determine toxic heavy metals(Pb2+, Cu2+) in river water. SEM, XRD and FTIR were used to characterize the structure and phase of β‐CD‐NH2‐Fe3O4. DPV results indicated that β‐CD‐NH2‐Fe3O4 modified GCE possessed large active area and excellent electron transfer. Under the optimum conditions, the peak current was proportional to the ion concentration in the range of 40 nM∼10 μM. LOD of Pb2+ and Cu2+ in this method was 1.71 nM and 1.57 nM, respectively. Compared with other similar results reported in the literature, the β‐CD‐NH2‐Fe3O4 modified electrode exhibited wider linear response range while with comparable lower LOD. It also exhibited excellent stability, reproducibility and anti‐interference ability. [ABSTRACT FROM AUTHOR]

The rapid and sensitive surface-enhanced Raman scattering (SERS) detection of molecular biomarkers from real samples is still a challenge because the intrinsically trace analytes may have a low molecular affinity for metal surfaces. Herein, we develop a smart signal conversion and amplification strategy based on silver–gold–silica core-satellite structure nanoparticles (Ag@Au@SiO2 NPs) to sensitively detect low adsorptive vitamin E using SERS, which has been considered a biomarker of neuromuscular disorders when its abnormal content is measured in the serum of patients. Through the reducibility of vitamin E, Ag+ ions are rapidly reduced to Ag atoms, resulting in the epitaxial growth of Ag nanocrystals on gold nanoparticles forming satellite particle–particle gap-narrowed Ag@Au@SiO2 NPs. The generated strong plasmonic field dramatically enhances the Raman signal of the Raman reporter molecule 4-aminothiophenol (4-ATP) and the detected vitamin E molecules at an estimated level of 58.19 nmol L−1. The sensitivity of this operational SERS strategy provides tremendous prospects for the screening of neuromuscular disorders. [ABSTRACT FROM AUTHOR]

Schematic diagram for efficiently removal of Pb (Ⅱ) based on UiO-67-Rhodanine-3-acetic acid (Rd) composites. [Display omitted] • A new UiO-67-Rhodanine-3-acetic Acid(Rd) composites was synthesized successfully. • The composites exhibited superfast removal efficiencies for Pb (II) with huge adsorption capacities of 309.8 mg g−1. • The proposed method provided a new, effective and straightforward method for rapid and superior trapping Pb (II). • The removal of Pb (II) by UiO-67-AC-Rd as advanced sorbents was presented and further provided a new pathway to application for wastewater. Metal organic frameworks (MOFs) have the advantages of large specific surface area, high porosity, controlled structures and strong stability, and were excellent adsorbents for the efficient trapping of heavy metals. In this work, two morphologies of Zr-MOF composites (UiO-67-AC-Rd and UiO-67-FA-Rd) under different solvent conditions were synthesized by a sequential solvothermal process. The properties of the composites were characterized by SEM, TEM, XRD, XPS, and BET, and the adsorption capacities of Pb (II) were investigated in detail. The excellent performance of UiO-67-AC-Rd exhibited superfast removal efficiencies for Pb (II), ascribing to its surface contains plentiful oxygen, nitrogen and sulfur functional groups and large specific surface area, which makes it have fascinating properties in removing Pb (II), and the maximum adsorption capacity of Pb (II) was 309.8 mg g−1. Chelation and electrostatic adsorption were considered as the main adsorption mechanisms. Adsorption isotherms were fitted well using the Langmuir and Freundlich model, and the adsorption thermodynamics indicated that the adsorption process was endothermic and spontaneous. The UiO-67-AC-Rd composites maintained excellent adsorption capacity for Pb (II) after four consecutive cycles, and the removal efficiency was above 74 %. The study will further provide a new pathway to the application of UiO-67-Rd composites in the adsorption of heavy metals in wastewater. [ABSTRACT FROM AUTHOR]

[Display omitted] • A durable hydrophobicity hydrazone covalent organic framework (BTCH-PTA-COF) has been developed as SPME fiber coating. • BTCH-PTA-COF processes large specific surface area, good chemical and thermal stability. • The BTCH-PTA-COF fiber has perfect extraction efficiency for PAHs. • The adsorption mechanism was confirmed by the density functional theory (DFT) calculation. In this study, a durable hydrophobicity hydrazone covalent organic framework (BTCH-PTA-COF) has been developed as fiber coating, which was applied to solid-phase microextraction (SPME) of polycyclic aromatic hydrocarbons (PAHs). The hydrophobic and π-π packing interactions between BTCH-PTA-COF and PAHs were confirmed by contact angle experiments and Van der Waals surface electrostatic potential analysis. Further, large specific surface area, good chemical and thermal stability have positive promoting effect on extraction. The method of wide linearity (0.25–300 µ g·L−1), low detection limits (0.03–0.05 µ g·L−1) and high enrichment factors (767–1411) for the detection of PAHs is explored, coupling BTCH-PTA-COF based SPME with gas chromatography with hydrogen flame detector (GC-FID). The relative standard deviations (RSDs) for inter-day and intra-day extractions of PAHs are ranging from 4.1 % to 9.6 % and 2.9 % to 6.4 %, respectively. The method successfully detected and quantified trace PAHs in tea beverages and river water samples with recoveries from 88.5 % to 104.8 %. The BTCH-PTA-COF coated fiber is ultra-stable in recycled extraction and reused at least 120 times, which could surpass published and commercial SPME fiber. [ABSTRACT FROM AUTHOR]

A fluorescent probe based on single metal–organic framework material without additional fluorophores and active sites can significantly improve the stability of the probe for detection, and has very important application value in environmental analysis and detection. In this paper, a simple and rapid fluorescence detection method was established with Zn-MOF, which realized the highly sensitive detection of tetracycline antibiotics and NH4+ in water. The prepared Zn-MOF has abundant pores and can exist stably in water. When tetracycline antibiotics are present in Zn-MOF aqueous solution, based on the unique coordination ability between Zn and N, tetracycline antibiotics rich in N will be adsorbed into the pore canals of MOF, and aggregation-induced luminescence will occur. The original non-fluorescent Zn-MOF will immediately produce yellow fluorescence, realizing the detection of tetracycline antibiotics in water, with the limit of detection reaching 0.017 μM in a linear range of 0.02–13 μM. Zn-MOF is further used for the detection of tetracycline antibiotics in actual samples of milk and honey. Oxytetracycline (OTC) with the best fluorescence response of tetracycline antibiotics was coated on Zn-MOF to synthesize OTC@Zn-MOF fluorescent probe. NH4+ will replace the original ligand of Zn-MOF, which will disintegrate MOF and release OTC, resulting in a fluorescence decrease. Therefore, NH4+ can be detected with low limit of detection (0.038 μM) in a linear range of 0 to 3 mM. The probe is expected to be able to detect ammonia in the environment. [ABSTRACT FROM AUTHOR]

As a new low-cost photothermal nanoprobe, Prussian blue nanoparticles (PB NPs) have been demonstrated to have more potential in photothermometric-based point-of-care testing (POCT) application. However, most of the existing PB NP-based photothermometric sensors were constructed mainly relying on in situ generation of PB NPs or their combination with antigens and antibodies, therefore usually suffering from the inherent defects like complicated preparation and cumbersome surface process as well as high-cost modification. To break this limitation of PB NP-based photothermometric POCT, we proposed an ingenious redox reaction-controlled nanoprobe conversion strategy and successfully applied to photothermometric detection of ascorbate oxidase (AAO). In this design, the heat of PB NP photothermal system under 808-nm laser irradiation dramatically decreased with the addition of AA, due to a unique AA-induced Prussian blue to Prussian white (PB-to-PW) conversion. Upon AAO addition, the heat of reaction system increased because of the enzymatic catalytic reaction between AAO and AA, which led to a significant reduction of AA and resultantly inhibited PB-to-PW conversion. Such target-mediated nanoprobe conversion resulted in an obvious temperature change that could be easily detected by a common thermometer and exhibited good linear ranges from 0.25 to 14 mU/mL with a detection limit as low as 0.21 mU/mL for POCT analysis of AAO. This facile, convenient, and portable photothermometric sensing platform provides an innovative route for the design of PB NP nanoprobe-based photothermometric detection methods. [ABSTRACT FROM AUTHOR]

A new signal-amplified photothermometric sensor of Ag+ was explored based on a simple yet effective integration of inorganic and organic photothermal probes, mainly depending on the successful exploitation of a dual-signal transduction channel originating from the inherent photothermal property and the peroxidase-like activity of Prussian blue nanocubes (PB NCs). [ABSTRACT FROM AUTHOR]

In this study, we found that spermine (SPM) could enhance electrochemiluminescence (ECL) intensity of Au−Ag bimetallic nanoclusters (Au−Ag BNCs) with triethylamine (TEA) as a co‐reactant. An ECL sensor was fabricated to detect SPM, which contained Au−Ag BNCs as ECL emitters and conductive hydrogel containing polyaniline‐amino trimethylene phosphonic acid (PANI‐ATMP) as an immobilizing matrix. The increased ECL intensity of SPM was linear with the logarithm of concentrations of SPM in the range of 1 pM to 10 μM with high selectivity, excellent stability, and the limit of detection is 0.11 pM (S/N=3). This sensor realized the detection of SPM in urine samples, which was fast and economic, possessing potential applications for SPM detection in clinical and bioanalysis. [ABSTRACT FROM AUTHOR]

[Display omitted] Photocatalysis utilizing solar energy is a promising strategy for mitigating energy crisis and environmental pollution. Exploring a cost-effective, stable, eco-friendly, and efficient photocatalytic system is extremely urgent. Herein, copper encapsulated within nitrogen-doped carbon nanosphere (Cu@N C) possessing a unique core-shell structure with high catalytic activity was prepared by ion-exchange and pyrolysis using resin as support. The protective carbon shell can prevent the leaching of metal ions and deactivation of the catalyst. Benefiting from the special structure, Cu@N C exhibited excellent activity and durability toward the degradation of tetracycline by the activation of peroxymonosulfate (PMS). The radical trapping experiments and electron spin resonance analyses were applied to elucidate the main reactive species. This work highlights the great potential of Cu@N C core-shell nanosphere as photocatalyst, which provides a new opportunity for the remediation of environmental pollution. [ABSTRACT FROM AUTHOR]

Main observation and conclusion: The intracellular delivery of metal‐organic frameworks (MOFs) encapsulated with functional biomolecules represents a promising avenue in the field of biomedicine and biosensing. To improve the cellular uptake efficiency of MOFs, here we report the fabrication of cancer cell‐derived exosome membrane (EM)‐coated zeolitic imidazolate framework‐8 (EM‐ZIF‐8) nanoparticles by using a microfluidic sonication device. EM‐ZIF‐8 nanoparticles loaded with FITC‐labeled bovine serum albumin (BSA) can be taken up by cancer cells and evade phagocytosis more efficiently than their counterparts (ZIF‐8 nanoparticles). Moreover, we use EM‐ZIF‐8 loaded with Rhodamine B (RhB) for in situ imaging of cellular adenosine triphosphate (ATP). The shield effect of ZIF‐8 suppresses the fluorescence of RhB, and the presence of ATP disrupts the ZIF‐8 structure based on the competitive coordination between ATP and Zn2+, leading to the restoration of RhB fluorescence. This method allows accurate detection of the fluctuation of ATP in A549 cells induced by Ca2+ or 2‐DDG treatment. The devised biomimetic EM‐ZIF‐8 nanoparticles thus provide an efficient platform for intracellular drug delivery and ATP sensing. [ABSTRACT FROM AUTHOR]

[Display omitted] • Different functional groups modifying WO 3 /R-MOFs (R = NH 2 , C 5 H 11 , C 5 F 11) were designed. • Hydrophobic WO 3 /C 5 F 11 -MOF improves oxygen mass transfer. • The formation of electron-deficient region in WO 3 /C 5 F 11 -MOF prolongs the relaxation time of electrons. The solar-driven photocatalytic degradation of persistent organic pollutants is considered as a promising water treatment approach. Nevertheless, the activity of photocatalytic degradation of pollutants is still limited by the rapid carrier recombination and sluggish oxygen mass transfer. Herein, we designed different functional groups modified WO 3 /R-MOF (MOF: MIL-125-Ti, R = NH 2 , C 5 H 11 , C 5 F 11) heterojunction to overcome the aforementioned limitations. Among them, WO 3 /C 5 F 11 -MOF exhibited an excellent degradation efficiency of 91.6 % for 4-chlorophenol pollutants, which was seven and two times higher than that of WO 3 /NH 2 -MOF and WO 3 /C 5 H 11 -MOF, respectively. The WO 3 /C 5 H 11 -MOF and WO 3 /C 5 F 11 -MOF exhibited hydrophobic and formed microscopic triphase interface, which increased oxygen transfer. Furthermore, strong electron-withdrawing property of fluorine in the C 5 F 11 - ligand generated electron-deficient regions, increasing the transfer rate of photo-generated electrons and prolonging the relaxation time of electrons. Thus, hydrophobic WO 3 /C 5 F 11 -MOF not only regulates the catalytic interface microenvironment, but also effectively inhibits the recombination of photo-generated carrier. This study provides an efficient strategy to achieve excellent photocatalytic activity via interfacial engineering. [ABSTRACT FROM AUTHOR]

• An innovative MOFs@COFs-based molecular trap materials were successfully prepared. • The hierarchical core–shell composite was used as solid-phase microextraction (SPME) fiber coating. • The possible adsorption mechanism was systematically verified and explained. • The proposed method provided a new, effective and low-cost method for rapid and superior capture PAHs. In view of the serious carcinogenic, teratogenic and mutagenic properties of polycyclic aromatic hydrocarbons (PAHs), which cause significant harm to human beings and the environment. Therefore, developing rapid adsorption and efficient analytical methods are research topic with practical significance. Herein, an innovative MOFs@COFs-based molecular trap materials were prepared with hierarchical porous core–shell structure and used as solid-phase microextraction (SPME) fiber coating, which combined with high performance liquid chromatography (HPLC) to achieve the efficient separation, capture, and detection for 7 PAHs in real samples. The possible adsorption mechanism was systematically verified and explained. Under the optimized conditions, the method developed in this experiment had a wide linear range (0.005–400 µg·L−1) with a good linear correlation coefficient (R2 > 0.9984), low detection limits (0.002–0.405 µg·L−1, S/N = 3) and low quantification limits (0.005–1.351 µg·L−1, S/N = 10). The relative standard deviations of individual fibers and different batches of fibers were 0.26–3.64% and 0.40–5.91%, respectively. Besides, the fiber showed higher enrichment capacity and extraction efficiency for PAHs compared to commercial SPME fibers and other material fibers, and exhibited excellent acid-base stability and reproducibility. This work provided a favorable synthetic pathway for the preparation of MOFs@COFs composites by layer-modified assembly synthesis strategy, showed excellent practical applicability as a SPME fiber coating combined with HPLC, and could be realized to provide technical support for future studies on the separation, adsorption, and analysis of PAHs in the petrochemical industrial zone of the Yellow River Basin. [ABSTRACT FROM AUTHOR]

A new carbon black (CB)-doped Ce (III, IV)-MOF composite with dumbbell-shaped was ultrarapid synthesized at room temperature for simultaneous detection of dopamine (DA) and acetaminophen (AC) in complex matrices samples by electrochemical method. [Display omitted] • A carbon black-doped Ce (III, IV)-MOF composites was synthesized by ultrarapid method at room temperature. • The mixed-valent composites was used as electrochemical sensor for simultaneous detection of dopamine (DA) and acetaminophen (AC). • The excellent performance of the homemade electrochemical sensor was attributed to the conductivity of carbon black, the excellent electrocatalytic performance of Ce(III, IV)-MOF and the synergistic effect of both. • The proposed method provided a rapid, effective and low-cost method for superior capture DA and AC. Simple and rapid analytical methods for pharmaceuticals and personal care products (PPCPs) are in high demand for environment monitoring. Herein, an in-situ doping strategy was used to ultrarapid synthesize carbon black (CB)-doped Ce (III, IV)-MOF composite with dumbbell-shaped structure at room temperature, which had been used as an electrochemical sensor for the effective and simultaneous detection of typical PPCPs such as dopamine (DA) and acetaminophen (AC) in complex matrices samples using different pulse voltammetry (DPV). Scanning electron microscope (SEM), Nitrogen adsorption-desorption, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), and X-ray powder diffractometer (XRD) were used to characterize the morphological and electrochemical properties of synthesized a series material. The mixed-valent CB/Ce (III, IV)-MOF with excellent pore structure properties provided more exposed active sites, which were more conducive to adsorption and thus improved sensing performance. The result showed that the proposed method had a wide linear range (for DA: 0.3–252.0 µM, for AC: 0.3–252.0 µM) and low detection limits (for DA: 0.0955 µM, for AC: 0.1170 µM). Based on the synergistic effect of both CB and Ce (III, IV)-MOF, the composites modified electrodes had excellent electroanalytical capability for DA and AC, which could be used for efficient and rapid monitoring of ECs and the construction of new electrochemical sensor based on MOFs. [ABSTRACT FROM AUTHOR]

In situ reduction of AgI to Ag nanoparticles (Ag NPs) supported on C-doped boron nitride (AgI/BN-C) was developed for CO 2 electroreduction to CO with a much enhanced faradaic efficiency (FE) of 99.5 % and a high current density of 56.3 mA cm−2. The enhanced performance is mainly attributed to the controllable construction of Ag0-Ag+ sites, which effectively provides a large number of active sites, enhances the adsorption strength of the intermediate and accelerates the reaction kinetics. [ABSTRACT FROM AUTHOR]

Development of highly sensitive and accurate biosensors still faces a great challenge. Herein, glucose oxidase (GOx) is efficiently immobilized on the AuCu hydrogels owing to their porous structure and interfacial interaction, demonstrating enhanced catalytic activity, satisfactory stability and recyclability. Besides, by integration of AuCu@GOx and electrochromic material of Prussian blue, a sensitive and stable biosensing platform based on the excellent electrochromic property of Prussian blue and the enhanced enzyme activity of AuCu@GOx is developed, which enables the electrochemical and visual dual-mode detection of glucose. The as-constructed biosensing platform possesses a wide linear range, and good selectivity for glucose detection with a limit of detection of 0.82 μM in visual mode and 0.84 μM in electrochemical mode. This easy-to-operate biosensing platform opens a door for the practical application of the multi-mode strategy for glucose detection. [Display omitted] • AuCu hydrogels with porous structure can immobilize glucose oxidase with enhanced catalytic activity and stability. • A biosensing platform is developed based on the electrochromic property and enhanced enzyme activity • An electrochemical and visual detection strategy is used for glucose biosensing. [ABSTRACT FROM AUTHOR]

Porphyrins, as significant electrochemical luminaries, have garnered extensive attention due to their distinctive structure and superior photoelectric properties in recent years. However, the potential aggregation resulting from water insolubility in aqueous phases, as well as its inherent instability and weaker Q-band, continue to pose challenges for the electrochemiluminescence (ECL) applications of porphyrins. This review provides a comprehensive summary of different strategies aimed at achieving high efficiency of porphyrin in ECL and signal amplification. Finally, a critical perspective and future prospects regarding the developmental trends of porphyrins are presented. • Porphyrin-based luminophores were summarized. • Auxiliary strategies for signal amplification were discussed. • A critical perspective and future prospects regarding the developmental trends of porphyrins was presented. [ABSTRACT FROM AUTHOR]

[Display omitted] • Proposes a cost-effective and efficient photochemical modification system, which introducing a BiVO 4 seed layer to improve photoelectrochemical (PEC) performance without any cocatalysts or sacrificial agents. And the photocurrent density of BiVO 4 seed layer with a thickness of 312 nm was improved by 40% to 0.99 mA cm−2 at 1.23 V RHE. • The BiVO 4 seed layer effectively inhibits the recombination of electron-hole pairs and improves the charge transfer efficiency , leading to a "slow" decrease in the current density of the composite photoanode from 32% to 9.8%. • Using the feedback model of the scanning photoelectrochemical microscopy (SPECM) to in-situ quantitatively study the hole transfer kinetics of BiVO 4 with different seed layer thicknesses, revealed that photoelectrode with a seed layer thickness of 312 nm have the highest kinetic rate constant (0.62 × 10−2 cm s−1), which is roughly 5 times of the pristine photoelectrode (0.11 × 10−2 cm s−1). Although the catalytic effect can be enhanced by using sacrificial agents, it still faces numerous difficulties in large-scale production applications. Investigating the improvement of photocatalytic efficiency without sacrificial agents is therefore crucial. This study proposes a cost-effective and efficient photochemical modification system that utilizes a seed layer of BiVO 4 to improve photoelectrochemical (PEC) performance, the result shows that the photocurrent density of BiVO 4 with a seed layer thickness of 312 nm was improved by 40% to 0.99 mA cm−2 at 1.23 V RHE without any sacrificial agent. Meanwhile, Electrochemical impedance spectroscopy (EIS) and intensity modulated photocurrent spectroscopy (IMPS) demonstrated that the introduction of the seed layer effectively prevents the recombination of electron-hole pairs and improves the charge transfer efficiency, leading to a "slow" decrease in the current density of the composite photoanode (from 32% to 9.8%) in combination with the linear sweep voltammetry (LSV) results. We exhibit the scanning photoelectrochemical microscopy (SPECM) method to in-situ quantitatively study the hole transfer kinetics with different seed layer thicknesses using the feedback model and find those photoelectrodes with a thickness of 312 nm has the highest kinetic rate constant of 0.62 × 10−2 cm s−1 which is approximately 5 times higher than that of the pristine photoelectrode (0.11 × 10−2 cm s−1). [ABSTRACT FROM AUTHOR]

Advanced oxidation processes (AOPs) are regarded as promising strategies for generating powerful oxygen-containing radicals that can degrade nearly all organic compounds. However, developing catalysts with highly active sites for carrying out AOPs is still a significant challenge. Herein, we design and synthesize of ultra-small cobalt nanoclusters with N, O-dual coordination (O-Co-N) on porous carbonized peat moss (CPM-Co-2) for the efficient catalytic purification of water through peroxymonosulfate (PMS)-based AOPs. Density functional theory calculations revealed that introducing O causes the d -band center of the O-Co-N configuration to shift away from the Fermi level, which significantly decreased the desorption energy of sulfate radicals (SO 4 •−) and accelerated the rate-limiting step to promote the reaction. The CPM-Co-2 showed excellent catalytic activity and stability in the remediation of organic pollutants and bacteria. The immensely increased catalytic activity achieved through regulating the metal coordination environment provided useful insights for the future design and synthesis of catalyst. [Display omitted] • Tuning the electronic structure of ultra-small nanoclusters using N, O-dual coordination. • Large scale, low cost, and repeatability of catalyst greatly enhance the practical application of AOPs. • The O-Co-N active site reduces the desorption capacity of SO 4 •− and increases the generation rate of reactive oxygen species. • Excellent catalytic activity and stability in the remediation of organic pollutants and bacteria. [ABSTRACT FROM AUTHOR]

Solar-driven evaporation is thought to be a fantastic strategy for freshwater generation, but the evaporated vapor inevitably accumulates volatile organic compounds (VOCs) in the initial wastewater, leading to secondary pollution of the condensed water. Here we demonstrate a dual-functional solar evaporator based on the graphite-N (g-N) doped biochar derived from biomass waste for simultaneous desalination and VOCs degradation. The doped g-N can activate potassium peroxomonosulfate (PMS) to produce plenty of singlet oxygen (1O 2) and thus decomposing VOCs, whereas numerous micropores can capture VOCs. Taking wood biomass waste as an example, its derived g-N doped wood carbon (g-N/WC) evaporator delivers a high degradation efficiency of ∼99.91 % toward VOCs (including phenol, Bisphenol A (BPA), 4,4′-Sulfonyldiphenol (BPS), and p-Chlorophenol (4-CP)), and a great evaporation rate of 1.31 kg m−2 h−1 under 1 sun. Life cycle assessment (LCA) results demonstrate that the environmental impacts across all categories and CO 2 emissions of the g-N/WC evaporator are reduced by up to 98 % and 82 %, respectively, compared with other emerging materials. The developed solar evaporator repurposes biomass waste to simultaneously solve water scarcity and waste mismanagement crises with an extremely low carbon footprint, representing a promising approach toward worldwide sustainable wastewater purification and biomass waste management. • All-in-one solar evaporator was designed for desalination and VOCs degradation. • Carbon footprint is reduced about 82 % comparing with other emerging materials. • Degradation efficiency is reached 99.9 % toward VOCs as the waste water evaporated. • Water treatment performance was well maintained for 7 days continuous test. [ABSTRACT FROM AUTHOR]

[Display omitted] • Synthesis of a novel MXene loaded gold nanocluster composite (BSA-AuCNs/MXene). • An efficient Hcy electrochemical sensor was constructed based on BSA-AuCNs/MXene. • It exhibited wide linear range and an ultra-low detection limit of 1.76 nM. • Electrochemical detection of Hcy in cell lysate was realized for the first time. The increased level of homocysteine (Hcy) becomes an independent risk factor for various diseases. Quantification of Hcy is helpful to the early diagnosis and treatment of related diseases. For this purpose, it is very necessary to explore innovative materials to construct sensitive electrochemical sensors. Herein, we designed and synthesized a novel composite (BSA-AuCNs/MXene) by using two-dimensional (2D) layered MXene as the matrix and supported with gold nanoclusters (BSA-AuCNs). Combining the properties of the above two materials, the composite was endowed with the ideal characteristics of electrochemical sensing materials such as high electrical conductivity, outstanding catalytic activity, large specific surface area, and good thermal stability. The constructed sensor exhibited excellent analytical behavior for Hcy with a super low detection limit (1.76 nM, S/N = 3). It also displayed satisfactory selectivity, reproducibility, and stability. In addition to detect Hcy in human serum, we also realized the electrochemical detection of Hcy in cell lysate for the first time. This work not only opens up a new way to broaden the application of MXene and gold nanoclusters in the sensing field, but also provides a possibility for their future application in the early diagnosis of Hcy-related diseases. [ABSTRACT FROM AUTHOR]

In this paper, the role of the halogen bond in capillary monolithic column microextraction was explored for the first time. Benzene-1,3,5-tricarbohydrazide (BTH) was synthesized as a functional monomer, N, N′-methylene bisacrylamide (MBA) and divinyl benzene (DVB) were used as cross-linking agents, the hybrid monolithic column of poly (BTH-co-DVB-co-MBA) was prepared using methanol and polyethylene glycol as pore-forming agents and azodiisobutyronitrile as the initiator. Due to the existence of BTH, a large number of nitrogen atoms (Lewis base) were introduced into the monolithic column, which could form a halogen bond with chlorine-containing organic pollutants and enhance its adsorption performance. Based on the monolithic column, a sensitive and environment-friendly solid-phase microextraction technology was studied. The monolithic column was integrated with high-performance liquid chromatography (HPLC) to extract and detect four kinds of chlorophenol in real water samples. Under best conditions, the method showed excellent extraction ability and linearity, with a linear correlation coefficient of 0.9958–0.9987, a low detection limit (LOD) of 0.04–0.23 μg L−1 (S/N = 3), and relative standard deviation (RSD) less than 3.09%. The recovery rate was kept between 87.30% and 123.00%, and the RSD was less than 3.83%, which indicated that the column had powerful capture performance, high precision, and strong anti-matrix interference ability in the real sample, and had potential application value in practical work. The work schematic diagram of the poly (BTH-co-DVB-co-MBA) monolithic column and the application in environmental samples. [Display omitted] • The halogen bond in capillary monolithic column microextraction was explored to the chlorophenol for the first time. • The powerful capture property and strong anti-matrix interference ability was attributed to the halogen bond. • The amount of eluent and sample was very few (eluent: 100 μL, sample: 1 mL), and the proposed method was green and environment-friendly. • The prepared in-situ polymerization monolithic column has small error and super-high reproducibility. [ABSTRACT FROM AUTHOR]

A ratiometric electrochemiluminescence strategy using a single luminophore for accurate and sensitive biomolecule detection could be immensely valuable in bioanalysis. Herein, an ultrasensitive ratiometric electrochemiluminescence sensing system was fabricated using a self-enhanced luminophore with dual-signal emission for the detection of spermine. A nanocomposite was synthesized by the covalent attachment of N, N -diisopropylethylenediamine onto glutathione-protected Au–Ag bimetallic nanoclusters (DPEA-GSH@Au/Ag BNCs). The nanocomposite exhibited efficient intra-cluster charge transfer to produce strong anodic self-enhanced electrochemiluminescence emission at 0.8 V without external co-reactants. Interestingly, the DPEA@GSH@Au–Ag BNCs exhibited cathodic electrochemiluminescence emission upon the addition of the co-reactant potassium persulfate at −1.6 V, exhibiting stable and efficient dual-signal electrochemiluminescence emission features at a continuous potential window of −1.75 to 1.2 V. Thus, they were used to fabricate a single-luminophore electrochemiluminescence sensor with dual emission. The cathodic emission of the biosensor gradually increased with increasing concentrations of spermine, whereas the anodic electrochemiluminescence intensity remained almost constant, enabling the ratiometric detection of spermine. The fabricated biosensor, with an internal standard, significantly improved the accuracy and reliability of spermine detection in a wide concentration range of 0.85 pM–100 μM, with a low limit of detection of 0.12 pM (S/N = 3) under optimum conditions. This single-luminophore electrochemiluminescence sensing system could be used for the detection of spermine and could guide the construction of ratiometric electrochemiluminescence sensors in the future. [Display omitted] • A self-enhanced nanocomposites of DPEA-GSH@Au/Ag BNCs were synthesized via simply covalent linking for simplifying the ECL biosensor design. • A ratiometric ECL biosensor was fabricated with single DPEA-GSH@Au/Ag BNCs and single co-reactant. • The proposed sensor could be applied to the detection of spermine in serum samples. [ABSTRACT FROM AUTHOR]

Trivalent organophosphorus luminophores attract considerable interest in life analysis due to their rich reactivity and wonderful life compatibility, but instability and aggregation-caused emissive quenching (ACQ) still hamper their practical applications. Herein, we report an air-stable trivalent phosphorus-embedded 1,2,3,4,5-pentaphenylphosphole (PPP) stabilized by a propeller-like noncoplanar chemical structure. Benefiting from its inherent strong aromaticity as well as the restriction of the intramolecular motions, PPP exhibits excellently aggregation-induced photoluminescence (PL) and electrochemiluminescence (ECL). Importantly, this work represents the first example of the organophosphorus ECL system that can highly detect the reactive oxygen species hypochlorous acid with a relatively lower detection limit as 8.5 nM, and highlights the promotion of aromaticity on ECL as well. [Display omitted] • Air-stable phosphole was stabilized by a propeller-like noncoplanar structure. • Phosphole could feature excellently aggregation-induced electrochemiluminescence. • High aromaticity was an important factor for enhancing the ECL performance. • Ultrasensitive detection of hypochlorous acid was achieved by such ECL system. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) are promising for the construction of nanofiltration membranes owing to their uniform, ordered channel structures and high chemical stability. However, developing a low-cost strategy for fabricating COF-based nanofiltration membranes and increasing the long-term stability of the membranes are challenging. Here, we developed a TpPa-wood membrane through the in-situ formation of massive imine COFs on the top surface of a wood block for the rapid and efficient nanofiltration-based separation of organic pollutants. The numerous hydroxyl groups of cellulose in wood provided nucleation sites for the growth of dense, defect-free COFs with a diameter of 1.8 nm. The nano porous COFs enabled efficient separation, while the long and low-tortuosity channels of wood with a diameter of 10–30 μm facilitated rapid water transport and augmented the mechanical robustness of the membrane. Therefore, the prepared TpPa-wood membrane showed an outstanding separation efficiency of ∼97.0% toward organic pollutants such as dyes and pharmaceutical molecules at a flux rate of 600 L m−2 h−1. In addition, the TpPa-wood membrane exhibited excellent stability at a wide pH range (3–11) and over continuous filtration for 48 h. The TpPa-wood membrane opens up a new avenue for rapid and efficient nanofiltration by combining the merits of nano porous COFs and biomass with numerous micro-channels and high hydrophilicity. [Display omitted] [ABSTRACT FROM AUTHOR]

• A hollow Co-MOF-74 incorporated electrospun nanofiber membranes (H-NFMs) were fabricated. • The H-NFMs were installed in a homemade filter to remove PAHs by the drain-type adsorption. • Hydrophobic H-NFMs have good mechanical, fast mass transfer capability, and favorable regeneration properties. • The method provided a new, effective and low-cost strategy for rapid and superior removal of PAHs. Developing efficient adsorbents for the removal of polycyclic aromatic hydrocarbons (PAHs) from aqueous solutions is an attractive and significative task. Herein, we demonstrate a route to fabricate hollow Co-MOF-74 incorporated electrospun nanofiber membranes and combine it with a homemade filter device for drain-type adsorption to remove PAHs from aqueous solutions. The removal efficiency of the prepared H-NFMs were more than 80% (except B[ghi]p = 75%), and exhibited excellent reusability for multiple regeneration cycles. In addition, the introduced H-Co-MOF-74 material possessed a large surface area (633.6 m2 g−1) and hollow structure, which could supply more exposed adsorption active sites, accelerate mass transfer and shorten the adsorption equilibrium time. By loading H-Co-MOF-74 in nanofiber membranes, H-NFMs have high hydrophobicity, good mechanical and thermal stability, while the filters and membranes can be easily recycled separately after the adsorption is completed. This study not only proposed a simple and rapid adsorption method of an efficient sorbent material but also provided an ingenious separation and removal strategy for other pollutants in aqueous solutions. [ABSTRACT FROM AUTHOR]

A novel SPME fiber based on silicone sealant/hollow ZnO@CeO 2 composite was developed for the enhanced capture of pesticides in water. [Display omitted] • A novel SPME fiber based on silicone sealant/hollow ZnO@CeO 2 composite with super-hydrophobicity was developed. • Hollow core–shell channels in ZnO@CeO 2 was conducive to the mass transfer to realize the enhanced capture. • The excellent adsorption property was attributed to π-π interaction, and hydrophobic interaction. • The prepared fiber was successfully applied in the analysis of pesticides in surface water. Herein, a novel solid phase microextraction (SPME) fiber coating based on silicone sealant/hollow ZnO@CeO 2 composite with super-hydrophobicity was designed, which could capture rapidly and determine efficiently-six pesticides combined with high-performance liquid chromatography (HPLC). The synthesis mechanism of ZnO@CeO 2 with core–shell structure was discussed. Under the optimized conditions, the developed method showed a wide linear range (0.026–200 µg/L) with good linearity (R2 greater than 0.9988), low detection limits (0.008–0.353 µg/L, S/N = 3), and quantification limits (0.026–1.175 µg/L, S/N = 10) for six pesticides. The relative standard deviations (RSD) of single fiber and different batches of fibers were 0.4–4.8 % and 0.6–5.3 %, respectively. In addition, compared with the commercial SPME fiber, the fiber showed better enrichment ability and extraction efficiency for pesticides, which might be due to the solid π-π accumulation, hydrophobic interaction, abundant adsorption sites, and hydrogen bonding between the coating and the target analyte. Besides, the hollow structure of the composite material, the rare earth metal oxide CeO 2 on the surface of the coating, and the silicone sealant all played a crucial role in the extraction process. Finally, the method had been successfully applied to determine the pesticides in real water samples, with the recovery rate ranging from 80.1 % to 108.2 % and RSD < 5.67 %. The experimental results showed that the Ss/ZnO@CeO 2 with a hollow core–shell structure had great application potential as a composite coating for solid-phase microextraction. [ABSTRACT FROM AUTHOR]

Provide more active sites and concise preparation is an effective technology in renewable energy storage sets. A soluble graphitic carbon nitride (SCN) nanosheets promoted two-dimensional nano electrochemical activity flake NiFe-LDH is successfully fabricated through electrostatic self-assembly, as a layer by layer high performance electrode (NiFe-LDH@SCN) for supercapacitor. The g-C 3 N 4 guarantees the effectiveness of the combination through the ζ-potential of g-C 3 N 4 flake (−19.5 mV) and NiFe-LDH flake (+15.6 mV), moreover, ensures the exposure of more active sites of NiFe-LDH. The optimized electrode shows an impressive specific capacitance of 1060.4 F g-1 at 1 A g-1 and remains 770.8 F g-1 at 10 A g-1. The fabricated hybrid supercapacitor (HSC) exhibits a magnificent energy density (up to 68.7 Wh kg-1) along with the power density of 827.5 W kg-1 in the wide voltage window of 1.7 V and a prominent long-term stability (83.3 % of capacitance retention even after 8000 cycles). Finally, two HSCs in series can light 40 LEDs. Hence, this work demonstrates the great potential of g-C 3 N 4 in developing high-performance LDH-based energy storage devices. [Display omitted] • The high performance electrode (NiFe-LDH@SCN) is fabricated through electrostatic self-assembly. • NiFe-LDH@SCN-32 electrode shows an impressive specific capacitance of 1060.4 F g-1 at 1 A g-1. • The NiFe-LDH@SCN-32//AC displays a high energy density of 68.7 Wh kg-1. • The capacitance retention is high up to 83.3 % after 8000 cycles. [ABSTRACT FROM AUTHOR]

• A unique MWCNTs in situ anchor MIL-101(γ-Fe 2 O 3) composite was synthesized successfully. • The composites was used as adsorbent of magnetic solid-phase extraction (MSPE) for the enrichment of PAHs. • The excellent property was ascribed to π-π stacking, hydrophobic and cationic-π interactions. • The proposed method provided a new, effective and low-cost method for rapid and superior capture PAHs. In this work, a magnetic MIL-101(γ-Fe 2 O 3)/MWCNTs composite derived from iron-based metal-organic frameworks (MIL-101(Fe)) with multi-walled carbon nanotubes (MWCNTs) was successfully synthesized by low-temperature calcination process. The composite was used as adsorbent of magnetic solid-phase extraction (MSPE) for enhanced and rapid enrichment of trace polycyclic aromatic hydrocarbons (PAHs) based on its strong π-π stacking interactions, hydrophobic and cationic-π stacking interactions. The pseudo-second-order kinetic model and Langmuir isotherm model could be applied to better describe the adsorption process. The maximum adsorption capacity for PAHs reached 93.9 mg g−1. In addition, the conditions of MSPE process were optimized by orthogonal array design (OAD). A MSPE-HPLC-UV method was established for the sensitive detection of PAHs in real water samples and exhibited wide linear range (0.05–1000 µg L−1), low detection limits (0.02–0.41 µg L−1) and high enrichment factors (44–169) for PAHs. The relative standard deviations (RSD) ranged from 0.8 to 4.0% and 1.2–7.2% for single batch and batch-to-batch, respectively, and the spiked recoveries at two levels of 10 and 50 µg L−1 ranged from 79.6 to 112% with RSD of less than 5.81%. The unique MWCNTs in situ anchor MIL-101(γ-Fe 2 O 3) composite with an outstanding PAHs adsorption performance provides a new opportunity and promising application in removal of toxic pollutants. [ABSTRACT FROM AUTHOR]

Schematic diagram for the selective and sensitive electrochemical detection of As (III) based on GO/UiO-67@PtNPs composites. [Display omitted] • A new GO/UiO-67@PtNPs composites with octahedral structure was synthesized successfully. • The obtained composites was used as electrochemical sensor for the ultrasensitive and selective detection of As (III). • The excellent property was ascribed to the electrical conductivity of GO and the electrocatalysis of PtNPs. • The proposed method provided a new, effective and low-cost method for rapid and superior capture As (III). Invisible arsenic is a highly toxic pollutant in water bodies. Therefore, a quick, simple, eco-friendly, and sensitive detection method is significant for environmental governance, toxicological evaluation, and human health. A novel platform has been put forward to the determination of arsenic (As3+) in the real wastewater. The sensing platform was established on the basis of octahedral UiO-67 metal–organic framework (UiO-67 MOF) and Platinum nanoparticles (PtNPs). The UiO-67 MOFs had a porous structure with a great specific surface area, which was beneficial to the adsorption and concentration of arsenic. Graphene oxide (GO) can be accelerated electron transfer and increased abundant active sites, while platinum nanoparticles (PtNPs) can be facilitated the selective recognition of As3+ due to their electrocatalysis. The electrochemical properties of the GO/UiO-67@PtNPs composites were studied. Under optimized conditions, the GO/UiO-67@PtNPs sensors can be applied to the ultrasensitive and selective monitoring of As3+ in an aqueous solution, and exhibited high electrochemical performance toward As3+, including a wider linear range of 2.7–33.4 nM, and a lower detection limit of 0.48 nM, which is lower than the safety standard of drinking water constructed by the World Health Organization (WHO, 10 μg L−1). In addition, the developed sensing platform displayed excellent anti-interference, reproducibility, reliability, and applicability for the determination of As3+ in different environmental samples. [ABSTRACT FROM AUTHOR]

• Au@THPP core–shell hybrid nanoparticle was synthesized by single one-pot method. • Au@THPP core–shell nanostructures showed steady reproducible and stronger photocurrent. • Au@THPP core–shell nanostructures were expected to be applied as sensor, photoelectronic devices and photosensitizer. We report one-pot synthesis of uniform Au@Porphyrin core–shell nanoparticles, which presented stronger photocurrent. The results showed it was a rapidly nucleation process to form Au NPs, and the THPP matrix inside Au NPs was polymerized by SEM, TEM, HRTEM, EFTEM, XPS and FT-IR. Due to the solvent effect in mix solvent, Au@THPP nanoparticles was dispersed well. This stronger photocurrent was rooted in the direct coupling effect of π electron of the porphyrin ring and surface plasmon of Au NPs. [ABSTRACT FROM AUTHOR]