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The electrocatalytic splitting of water to produce hydrogen is regarded as an efficient and promising strategy but is limited by its large overpotential; thus, a highly efficient electrocatalyst is urgently needed. Mixed metal doping is an important strategy in defect engineering because the heteroatoms can change the intrinsic structure to form defects by affecting the atomic coordination mode and adjusting the electronic structure, which is often accompanied by morphological changes. Herein, two-dimensional layered bimetallic Co–pydc containing axially coordinated water molecules was selected by producing surface defects through Fe doping in Co centers as bifunctional electrocatalysts for OER and HER. The optimized Co0.59Fe0.41–pydc possesses outstanding OER performance with the lowest overpotential of 262 mV to reach j = 10 mA cm−2, and Co0.75Fe0.25–pydc possesses superior HER performance with the lowest overpotential of 96 mV at j = 10 mA cm−2. Furthermore, the overall water splitting device assembled with Co0.59Fe0.41–pydc@NF//Co0.59Fe0.41–pydc@NF affords a current density of 10 mA cm−2 at only 1.687 V. This work emphasizes the surface defects formed by tuning the electronic structure of metal centres accompanied with morphological changes of bimetallic dopants for efficient overall water splitting. [ABSTRACT FROM AUTHOR]

The in situ monitoring of toxic volatile organic compound gases using metal oxide-based gas sensors is still challenging. Herein, mesoporous In2O3 nanoparticles, assembled using smaller nanoparticles, were synthesized via a facile solvothermal method and used to load Au nanoparticles to prepare mesoporous Au/In2O3 for ethanol detection. The obtained In2O3 and Au/In2O3 were meticulously analysed by XRD, SEM, BET, TEM and XPS techniques. It was revealed that Au nanoparticles were uniformly distributed on mesoporous In2O3 nanoparticles. Notably, the obtained mesoporous 1% Au/In2O3 is highly sensitive to ethanol gas at an optimal working temperature of 180 °C, showing a response of 55 to 50 ppm of ethanol, which is considerably higher compared to that of In2O3 nanoparticles. The significantly enhanced sensitivity results from the electronic and chemical sensitization effects of Au nanoparticles. Moreover, the mesoporous Au/In2O3 nanoparticles also showed eminent selectivity, short response/recovery time, low detection limit, good linear relationship, superb repeatability, and wonderful long-term stability, suggesting that Au/In2O3 nanoparticles have great potential application for in situ monitoring of ethanol gas. [ABSTRACT FROM AUTHOR]

Broadband photodetectors capable of detecting light across a wide spectrum ranging from visible to short wave infrared (SWIR) wavelengths have significant relevance in various fields, including space technology and civil applications. HgTe quantum dots (QDs) have emerged as a promising candidate for the development of low-cost broadband photodetectors. In this study, a photodetector based on a layered structure of indium tin oxide (ITO)/HgTe QD film/gold (Au) was designed and fabricated using a layer-by-layer spin coating method. The fabricated photodetector exhibited a broadband response from 400 nm to 2000 nm, covering the visible and SWIR regions. Its broad spectral range makes it suitable for a wide range of applications. Additionally, the photodetector demonstrated a fast response time of approximately 300 μs, enabling rapid detection and data acquisition. These results highlight the potential of HgTe QDs as a promising material for the development of advanced broadband photodetectors with fast response times. The simplicity of the device structure, combined with the low-cost fabrication technique, makes it an attractive option for commercialization and integration into various optoelectronic systems. [ABSTRACT FROM AUTHOR]

Droplet microfluidics has emerged as a powerful technology to perform high-throughput experiments, while artificial intelligence (AI) serves as a functional tool to analyze a large set of multiplex data. Their convergence creates new opportunities in autonomous system optimization and control, enabling various innovative functions and applications. In this study, we elucidate the basic principles of AI and elaborate on its main functions. The intelligent microfluidic systems applied in droplet generation, material synthesis, and biological analysis are summarized, with their working mechanisms and enabled new functions highlighted. Moreover, we elucidate current challenges in a more widespread combination of AI and droplet microfluidics and offer our perspectives on potential strategies to tackle these challenges. We hope that this review can deepen our understanding of intelligent droplet microfluidics and inspire more functional designs tailored to emerging demands. [ABSTRACT FROM AUTHOR]

Herein, a novel, efficient and metal-free multicomponent reaction of isocyanides, selenium powder and 3-aminooxetanes is reported. The reaction uses selenium powder as the selenium source and H2O as the sole reaction medium, delivering a series of 1,3-selenazolines under mild conditions. The transformation features good functional group compatibility, broad substrate scope and high atom economy, avoiding the use of unstable and toxic selenium agents, additional phase transfer catalysts and transition-metal catalysts, which is in line with the concept of green organic synthesis. In addition, the obtained selenazolines were easily applied to the derivatization of biologically active molecules, which provides a new avenue for the synthesis of drug-like organoselenium compounds. [ABSTRACT FROM AUTHOR]

One of the feasible strategies to enhance the photocatalytic properties of TiO2 is to broaden the visible light response range and accelerate the separation rate of photo-induced electron–hole (e−–h+) pairs by designing and synthesizing heterostructures using narrow-band-gap semiconductors. In this study, a ternary heterostructure based on MOF-derived TiO2 was first fabricated via the self-sacrificing template method followed by a two-step chemical bath process. The as-obtained CdS/ZnIn2S4/TiO2 ternary heterostructures exhibited better visible-light photocatalytic properties for the degradation of Rhodamine B (RhB) and tetracycline (TC) than single-component and dual-component systems. Among the ternary heterostructures, it was found that the CdS/ZnIn2S4/TiO2-II showed the highest photoreactivity of 95.3% for RhB removal and 91.8% for TC removal within 40 min. In addition, CdS/ZnIn2S4/TiO2-II could maintain its photocatalytic properties during the stability test. The improvement in photocatalytic properties is attributed to the reasonable construction of a ternary heterostructure, which significantly accelerates the separation and transport of photogenerated e−–h+ pairs, improves the specific surface area, and broadens the visible light response range. This study demonstrates a promising strategy for developing ternary heterostructures as effective photocatalysts for the degradation of organic pollutants. [ABSTRACT FROM AUTHOR]

In view of the problems surrounding the research and application of carbon materials, the process of choosing a carbon source is still not perfect. There are few studies concentrating on the establishment of structure–property relationships based on the choice of carbon source. In this regard, our present work contributes the design of an organic precursor that is expected to allow the controllable construction of the carbon material, thus regulating its functionality. A highly π-conjugated Schiff base moiety with alternating imine groups (C＝N) and benzene rings was incorporated into the main chain of a mesoporous polymer. For comparison, a bisphenol-A-type moiety was employed in the main chain of another mesoporous polymer. Using the mesoporous polymers as organic precursors for porous carbon sources, the formation of mesoporous carbon can be attributed to the presence of the highly π-conjugated Schiff base moiety due to its self-supporting effect and char-forming ability, which are absent in the bisphenol-A-type moiety. However, we are not only concerned with the contribution from the chemical structure of the designed precursor to the controllable construction of mesoporous carbon, but also concerned with its regulation of the electrochemical performance of the resulting material. Through characterization using cyclic voltammetry (CV), galvanostatic charge–discharge profiles, and electrochemical impedance spectroscopy (EIS), this kind of mesoporous carbon has been found to have excellent charge storage and transportation abilities and shows potential for application in the electrodes of electrochemical capacitors. [ABSTRACT FROM AUTHOR]

This study presents an innovative method for the highly sensitive detection of apurinic/apyrimidinic endonuclease 1 (APE1), a crucial biomarker and target for cancer diagnosis and treatment. The method is predicated on our discovery that the apurinic or apyrimidinic site (AP site) can inhibit the activity of Taq DNA polymerase. Subsequent experiments further led to the development of a new amplification method based on the digestion activity of Lambda exonuclease. This approach showed potential to detect trace amounts of APE1 in biological samples with high sensitivity. [ABSTRACT FROM AUTHOR]

An increase in environmental awareness has resulted in a significant shift in research towards more renewable and sustainable energy sources and better waste valorization technologies. Within this vast field, biomass conversion technologies and biofuels have attracted much attention due to their adaptability potential to pre-existing infrastructure. Hydrothermal liquefaction is one of the most efficient biomass processing methods and has become a promising technology for future applications. Although many studies have been performed on this process, there is still much to discover about the technology; notably, there are critical gaps in substrate-specific reaction optimization, reactor design, and the effect of catalysts. In order to facilitate future studies reporting on these research gaps, this review summarizes the science and engineering applications of hydrothermal liquefaction of biomass. The effects of reaction temperature, retention time, biomass solid content, biomass type, solvent, and catalyst type on bio-crude yield and quality are discussed. In addition, reaction pathways, reactor types, and process economy are reviewed. In particular, due to their value for future full-scale applications, the emphasis is given to continuous-flow reactor systems. The secondary goal of this review is to serve as a reference point for the new researchers in the field. [ABSTRACT FROM AUTHOR]

Periodate oxidation reaction occurring directly on chitin has been neglected in polysaccharide chemistry so far. Herein, we present the first direct alkaline periodate oxidation of chitin, which demonstrates at the same time a novel approach for the preparation of chitin nanocrystals (ChNCs). This oxidation is based on an unprecedented selective reaction of non-ordered domains of chitin by the dimeric orthoperiodate ions (H2I2O104−) as the major species in alkaline surroundings. Nearly 50 wt% of non-ordered regions are dissolved after sequential accelerated partial deacetylation, periodate oxidation and β-alkoxy fragmentation, which allows the isolation of up to 50 wt% of uniform anisotropic zwitterionic ChNCs. [ABSTRACT FROM AUTHOR]

An amphiphilic tri-functional ligand (L1) containing a Lewis acidic phosphonium cation, a phosphino-fragment and a hydrophilic sulfonate anion (–SO3−) enabled Pd(OAc)2 to efficiently co-catalyze the hydroxycarbonylation of terminal alkynes towards α,β-unsaturated carboxylic acids. These incorporated functional groups synergistically promoted the reaction, which proved more effective than the ligands lacking –SO3− and/or phosphonium and the mechanical mixtures of the individual functional groups independently. The molecular structure of Pd-L1 indicated that –SO3− in L1 served as a secondary O-donor ligand with reversible coordinating ability, cooperating with the phosphino-fragment to stabilize the Pd-catalyst. The in situ FT-IR analysis verified that the formation and stability of Pd–H active species in charge of hydroxycarbonylation were dramatically facilitated by the presence of L1. It was believed that, over the L1-based Pd-catalyst, H2O was cooperatively activated by the Lewis acidic phosphonium via "acid–base pair" interaction (H2O → P(V)+) and by the hydrophilic SO3−via hydrogen bonding (SO3−⋯H2O), giving rise to the formation of dimeric and mono-nuclear Pd–H species driven by reversible SO3−-coordination. In addition, the L1-based Pd-catalyst could be immobilized in the ionic liquid [Bmim]NTf2 for six-run recycling uses without obvious activity loss and detectable metal leaching. [ABSTRACT FROM AUTHOR]

The upgrading of lignin is a sustainable and promising pathway for fossil-based aromatic compounds but always faces low selectivity. Herein, a metal-free photocatalyst, 2,4,6-triphenylpyrylium tetrafluoroborate (TPP), was illustrated to remarkably facilitate the regioselective oxidative Cα–Cβ bond cleavage of β-1 and β-O-4 lignin alcohol/ketone models into aromatic acids (92–99% yields) under visible-light irradiation at room temperature without any additive/co-catalyst, which was enabled by the synergistic effect of Cβ–H⋯C(TPP) interaction and·˙O2−/1O2 species. The synergy of the catalyst–substrate interaction and active species offers a reference for the enhancive and selective transformation of polymeric biomass and complex molecules. [ABSTRACT FROM AUTHOR]

An approach for N-formylation of amines was developed using NaBH(OAc)3 as a reductant under an atmospheric pressure of CO2 at 50 °C. The corresponding formylated products of various amines, including aliphatic and aromatic amines, amines with reductive-sensitive nitro groups and alkynyl groups and benzamides were obtained in good to excellent yields, and the possible reaction mechanism was also proposed. [ABSTRACT FROM AUTHOR]

Compact and dense zeolite membranes were prepared on the inner surface of 170 mm long ceramic tubes by maintaining the pressure difference between the two sides of the support during the hydrothermal synthesis process. The effects of the pressure difference on the formation of NaA zeolite membrane were investigated in detail by X-ray diffraction spectroscopy (XRD) and scanning electron microscopy (SEM). The characterization results showed that the pressure difference created by controlling temperature or vacuum not only continuously drove fresh synthesis solution to the inner surface of the support, but also increased the binding force of the zeolite membrane to the support. However, a very large pressure difference led to a large amount of Si/Al active ingredients entering the channels of the support and blocking the pores, resulting in decrease in the permeability of the membrane. Gas permeation performance demonstrated that the pressure difference produced by controlling either the temperature or vacuum resulted in membranes with the highest permselectivities of H2 over other gases at the pressure difference of ca. 0.05 MPa between the two sides of the support. At 25 °C and 0.1 MPa, the permselectivity of H2 over N2 through the zeolite membrane synthesized by the pressure-driven method was as high as 5.21, and it was much higher than the corresponding Knudsen diffusion coefficient. [ABSTRACT FROM AUTHOR]

In this study, a mesoporous biocarbon material (BCM) with connected pore channels and a large specific surface area (525.83 m2 g−1) was prepared by a carbonization approach with inexpensive hemp stem as the raw material. The BCM was used as a template to fabricate porous nickel–cobalt oxide (Ni–Co-O) nanocomposite structures in situ. The composition of the Ni–Co-O nanocomposites was readily controlled by adjusting the Co-to-Ni ratio of the initial nickel and cobalt nitrates. Furthermore, we constructed porous Ni–Co-O nanocomposite-based sensors. The room-temperature (RT) NH3 sensing results indicated that the sensor with the best performance exhibited a high response of 3 to 100 ppm, a low detection limit of 50 ppb, good stability (higher than 7 weeks), and excellent reversibility and selectivity. Therefore, the Ni–Co-O nanocomposite, featuring a large specific surface area and meso/micropore distributions, is a strong candidate as a key material for the fabrication of RT NH3 detection sensors. [ABSTRACT FROM AUTHOR]

In this study, several polysaccharide derivatives, carboxymethyl cellulose sodium (CMC), carboxymethyl chitin (CMCH) and sodium alginate (HCM), were introduced as the template in the preparation of Cu2O. Polysaccharides mainly serve as templates by selectively adsorbing onto the {111} faces of Cu2O crystals. The different adsorption thicknesses of the polysaccharide adsorption layers on the {111} surfaces and crystal corners of the Cu2O crystals cause Cu2O crystals to transform from octahedrons to octa-pods. The relative adsorption tightness (AC) of the three polysaccharides on the {111} planes of Cu2O crystals are AC(HCM) ＞ AC(CMCH) ＞ AC(CMC), which leads to intact Cu2O octa-pods, octa-pods with apex angles that are smaller plates or shallower pits, and octa-pods with apex angles that are depressed pits, respectively. In addition, to our knowledge, it is the first time that Cu2O octa-pods with jagged crystalline edges are obtained by using the CMC template and Ostwald ripening process. Selective adsorption of the polysaccharide template on the {111} plane of the Cu2O crystal can prevent the effect of external conditions, such as the initial reaction temperature, on {111} faces, which effects the morphology of the ultimate Cu2O crystal and favors the retention of the {111} surface. Polysaccharide adsorption layers with different thicknesses in different parts of the Cu2O crystal can be used to form Cu2O octa-pods with significantly increased foot lengths cooperating with a high concentration alkali solution. [ABSTRACT FROM AUTHOR]

Hydroaminomethylation of olefins with H2O as the hydrogen source was accomplished over an Ir-catalyst with the involvement of an ionic diphosphine (L6). The use of H2O as the hydrogen source could completely inhibit the hydrogenation of olefins. The π-accepting ability and improved stability of L6 endowed the corresponding Ir-catalyst with high activity and good longevity for recycling uses. [ABSTRACT FROM AUTHOR]

A bi-functional ligand (L1) containing a diphosphino fragment and sulfonic acid group (–SO3H) enabled PdCl2(MeCN)2 to efficiently catalyze the tandem bis-alkoxycarbonylation of terminal alkynes to produce aryl-/alkyl-substituted succinate (α,̉-diesters). It was found that the –SO3H incorporated in L1 indispensably assisted the Pd-catalyst in accomplishing this tandem reaction via intramolecular synergic effects. Co-catalysis over the L1-based Pd-catalyst was not due to the physical mixture of Xantphos and MeSO3H. In situ FTIR analysis verified that the formation and stability of Pd–H active species were facilitated by the presence of L1. The formation of stabilized diacylpalladium intermediate (F) was the critical driving force for the second-step methoxycarbonylation. DFT calculation was carried out to optimize the geometric structure of F, which indicated that the developed intramolecular O…H hydrogen bonds were an important structural feature to stabilize F. In addition, the L1-based Pd-catalyst could be recycled successfully for at least 3 runs in the ionic liquid [Bmim]NTf2 without obvious activity loss and detectable metal leaching. [ABSTRACT FROM AUTHOR]

Nanostructured CoO/NiO/CoNi composites as anode materials for lithium-ion batteries (LIBs) have been successfully prepared by a facile, straightforward, and large-scale dealloying method. The effects of NaOH solution concentration on the structure, morphology and electrochemical performances of the resulting products are studied systematically. These results indicate that the concentration of NaOH solution mainly influences the morphology of the CoO/NiO/CoNi composites. Cyclic voltammetry (CV) and charge–discharge tests have been conducted to assess the lithium storage performances of the CoO/NiO/CoNi anodes obtained from the 5 M NaOH solution. Remarkably, the CoO/NiO/CoNi anodes exhibit high specific capacity, excellent rate properties, and superb cycling stability. A reversible capacity is still maintained at 575 mA h g−1 after 500 cycles at a current density of 200 mA g−1. Even at a current rate of 2000 mA g−1, the capacity could reach 267 mA h g−1. The outstanding electrochemical properties of the CoO/NiO/CoNi anodes make them promising anode materials of LIBs and other energy storage applications. [ABSTRACT FROM AUTHOR]

Mono-phosphines (L1 and L2) and diphosphines (L3 and L4) with typical π-acceptor character were prepared and applied in Ir(i)-catalyzed N-alkylation of amines with alcohols. It was found that the π-acceptor character of the applied phosphines is closely correlated to the catalytic efficiency of the [Ir(COD)Cl]2 complex for this green reaction. Compared to PPh3 as the typical σ-donor (i.e. with poor π-acceptor character), L1–L4 all resulted in the efficient N-alkylation of aniline to benzyl-aniline. While L1–L4 coordinated to the Ir(i)-catalyst, the consolidated Ir–P linkages due to π-backdonation could well protect the Ir-catalyst against deactivation, giving rise to the N-alkylation of aniline. On the other hand, the stabilized Ir-catalyst with the involvement of L2 could be recycled successfully for at least 4 runs in the ionic liquid of [MePh3P]Br without the detectable leaching of Ir and P elements in the organic products. [ABSTRACT FROM AUTHOR]

Ordered tungsten and aluminum co-doped mesoporous KIT-6 catalysts (W-Al-KIT-6) with different Si/Al molar ratios were successfully synthesized by a one-pot synthesis method. The obtained W-Al-KIT-6 catalysts were tested for catalytic conversion of 1-butene and ethene to propene via isomerization of 1-butene to 2-butene and subsequent cross metathesis of 2-butene and ethene. Various characterization techniques, such as ICP-OES, XRD, BET, TEM, Raman, XPS and NH3-TPD, were used to characterize the catalysts. The introduction of Al did not change the mesoporous structure of KIT-6 when the nominal Si/Al was 10, 20 or 30. Moreover, the sample demonstrated a larger amount of acidic sites. The W-Al-KIT-6 catalysts with suitable Si/Al ratios illustrated a superior catalytic performance to W-KIT-6 catalyst. The origin of catalytic performance enhancement over W-Al-KIT-6 catalysts is preliminarily discussed and ascribed to the highly disperse W species and a large amount of acidic sites. The acidic sites were formed by the introduction of a suitable amount of Al in the W-KIT-6 framework, which accelerated the isomerization of 1-butene to 2-butene and promoted the cross metathesis of 2-butene and ethene to propene. [ABSTRACT FROM AUTHOR]

In this study, four bi-modal core-shelled contrast agents of SiO2(FITC)@Gd2O(CO3)2·H2O with varying shell thicknesses but the same cores have been prepared via a two-step wet chemistry method. The four samples were quite close to sphericity and their averaged diameters were 127, 140, 148.7 and 174.0 nm. The composition of their shells was also examined. As the shell thickness increased, the fluorescence intensity halved but the longitudinal relaxivity remained high (28, 29, 27, 24 mM−1 s−1). The measured relaxivities of the samples were more than 5.8 times higher than the relaxivity of Gd-DTPA-BMA in a 0.55 T MR (magnetic resonance) system. The levels of cytotoxicity were tested on four cell lines (293, HeLa, HFL1, MCF-7) and the results indicated that the samples were safe. The intracellular fluorescence in HeLa cells was clearly observed using laser confocal microscopy. These results showed that this material had potential for application in MR-fluorescence bi-modal imaging. [ABSTRACT FROM AUTHOR]

Selective photoconversions of photochromic diarylethene derivatives has been described using diarylethene derivative 1a as a model compound. Upon irradiation with 254 nm light, 1a undergoes photocyclization to yield the ring-closed isomer 1b in the absence of oxygen, or is transformed to the thiolactone derivative 1c in the presence of oxygen (in the air), respectively. It was found that 1b can be reversed back to 1a with visible light irradiation, the ring-opening and ring-closing photoswitch can be performed in the absence of oxygen. 1c is, however, photo-inactive and cannot be reversed back to 1a with UV or visible light irradiation. It was also found that 1c shows fluorescence whereas both 1a and 1b show no fluorescence. [ABSTRACT FROM AUTHOR]

The formal potential of c-type cytochromes expressed in the bacterial outer membrane was dependent on their redox state functioning in mediating extracellular electron transfer. Its negative (positive) shifting accompanying with the oxidization (reduction) of c-type cytochromes can serve to stabilize the redox states in a feedback manner. [ABSTRACT FROM AUTHOR]

Recently protein binders have emerged as a promising substitute for antibodies due to their high specificity and low cost. Herein, we demonstrate an electrochemical biosensor chip through the electronic labelling strategy using lead sulfide (PbS) colloidal quantum dots (CQDs) and the unnatural SARS-CoV-2 spike miniprotein receptor LCB. The unnatural receptor can be utilized as a molecular probe for the construction of CQD-based electrochemical biosensor chips, through which the specific binding of LCB and the spike protein is transduced to sensor electrical signals. The biosensor exhibits a good linear response in the concentration range of 10 pg mL−1 to 1 μg mL−1 (13.94 fM to 1.394 nM) with the limit of detection (LOD) being 3.31 pg mL−1 (4.607 fM for the three-electrode system) and 9.58 fg mL−1 (0.013 fM for the HEMT device). Due to the high sensitivity of the electrochemical biosensor, it was also used to study the binding kinetics between the unnatural receptor LCB and spike protein, which has achieved comparable results as those obtained with commercial equipment. To the best of our knowledge, this is the first example of using a computationally designed miniprotein receptor based on electrochemical methods, and it is the first kinetic assay performed with an electrochemical assay alone. The miniprotein receptor electrochemical biosensor based on QDs is desirable for fabricating high-throughput, large-area, wafer-scale biochips. [ABSTRACT FROM AUTHOR]

Correction for ‘An efficient and recyclable ionic diphosphine-based Ir-catalyst for hydroaminomethylation of olefins with H2O as the hydrogen source’ by Huan Liu et al., Chem. Commun., 2018, 54, 7979–7982. [ABSTRACT FROM AUTHOR]

The construction of bifunctional catalysts for the oxygen evolution reaction (OER) and urea oxidation reaction (UOR) is important for accelerating the development of the hydrogen economy. Herein, a novel three-dimensional core–shell heterostructure (Ni–Mo–S@NiFeLDH/NF) was prepared by vertically growing NiFe layered double hydroxide (NiFe LDH) nanosheets on nickel foam (NF)-supported arrays of Ni–Mo–S (Ni3S2, Ni0.96S, Mo2S3) nanorods via a hydrothermal–sulfide–hydrothermal process. Benefiting from the unique core–shell structure with numerous exposed active sites, the optimized Ni–Mo–S@NiFe LDH/NF shows excellent OER/UOR activity, with an overpotential of only 274 mV for OER to reach 100 mA cm−2 and 1.318 V for UOR to reach 10 mA cm−2. Moreover, the assembled Ni–Mo–S@NiFe LDH‖‖Pt/C urea electrolytic system requires only 1.348 V to achieve 10 mA cm−2, as much as 159 mV lower than pure water electrolysis. This work provides an idea for researching NiFe LDH-based OER/UOR bifunctional catalysts. [ABSTRACT FROM AUTHOR]

A PtAuBi-UPD composite electrocatalyst modified glassy carbon electrode (GCE) is prepared via the simultaneous underpotential deposition (UDP) of Bi and bulk deposition of Pt and Au, followed by stripping of the accessible Bi, and it shows high performance for the electrocatalytic oxidation and amperometric analysis of formaldehyde. [ABSTRACT FROM AUTHOR]

In this work, an electroanalytical platform for nereistoxin (NRT)-related insecticide detection is proposed on the basis of NRT induced DNA conformational switching and exonuclease III (Exo III) assisted target recycling. NRT-related insecticides were first hydrolyzed and converted into NRT with two thiol groups (–SH). Then, a cytosine–Ag+–cytosine (C–Ag+–C) mismatched base pair was adopted to induce a blunt-ended hairpin configuration of HP DNA. In the presence of converted NRT, it could take up Ag+ from HP DNA to change its conformation from a hairpin to single-stranded structure (HP ssDNA). Thereafter, the obtained HP ssDNA was further hybridized with an H1 hairpin probe on the electrode surface to trigger the Exo III cleavage process, releasing HP ssDNA for recycling leaving the G-quadruplex fragment of H1, which was used for hemin/G-quadruplex complex formation. The reversible redox reaction of Fe(III)/Fe(II) of hemin gave a remarkable electrochemical response for quantitative determination of the NRT-related insecticides. As an analytical model, a low detection limit of 3.9 ng L−1 and a wide linear range of 0.01–1500 μg L−1 with excellent selectivity were achieved for cartap detection. The proposed method also displayed great applicability for cartap detection in agricultural products. [ABSTRACT FROM AUTHOR]

One-dimensional ZnO nanospike arrays were prepared on substrates via a low temperature rapid water bath growth method based on the diluent of a nearly saturated solution. Commercial ZnO powder, NaOH and water were the source chemical reagents, without other reacting additives during the whole experimental process. Detailed structural and spectral characterization reveals the high crystallinity of the as-grown ZnO nanostructures, despite the fast growth process. The microstructure and crystalline states can be tailored via the appropriate control of variables such as reaction time, growth temperature and the dilution ratio of the near-saturated solution. The ZnO nanospike arrays contribute to the formation of a transparent superhydrophobic film as a result of their gradient refractive index structure and the ultra-low solid–liquid contact area under wetting conditions. Besides, highly crystalline two-dimensional ZnO nanosheets and three-dimensional ZnO microflowers were also acquired via growth control. And the successful growth of ZnO on a curved surface extends its application to various engineering interfaces with different surface morphologies. What is more, the whole growth mechanism was explored through the analysis of products growing in solution and on substrates. This approach contains a series of advantages for the preparation of scaled ZnO nanostructures with high crystallization and uniformity, such as low cost, low temperature (lower than 80 °C), rapid reaction (shorter than 30 minutes) and ease of control, which endows this approach with potential for application in optoelectronic devices. [ABSTRACT FROM AUTHOR]

The Suzuki–Miyaura reaction has greatly facilitated the construction of C–C bonds and is well appreciated in medicinal chemistry, yet transition metal residues in this process are an unavoidable challenge. Herein, we report the first visible-light-driven photocatalyst-free coupling reaction of alkenylboronic acids/esters with α-bromodifluoroacylarenes, providing streamlining access to a series of Suzuki coupling products. The reactions proceed under metal-free conditions with a wide substrate scope. Mechanistic experiments and DFT calculation studies revealed that halogen bonding interactions, mainly generated in situ between α-bromodifluoroacylarenes and tertiary amines, could promote the Csp3–Br bond homolytic cleavage from difluorobromoaryl ketones. [ABSTRACT FROM AUTHOR]

Alcohol solvents especially isopropanol were demonstrated for the first time to endow silver nanoclusters (AgNCs) in water with dramatically enhanced red fluorescence. More importantly, the specific iodide recognition capability of the AgNCs could thus be obtained towards a highly selective fluorimetric assay for detecting iodide ions in urine. [ABSTRACT FROM AUTHOR]

In the conceptual frame of "One Health", the safety crisis caused by various toxicological issues due to chemical exposure is of great concern. The urgent demand for environmentally safe chemicals is increasing the awareness of the importance of designing non-toxic chemical molecules. The expanding toxicological data can provide a foundation for studying interactions between the living organisms and environment. However, a large amount of toxicological data is fragmented and scattered in the literature and online resources. Thus, to promote the more efficient use of toxicological information, further collection and collation of the current toxicity data is urgent. In the present review, we discuss the application of existing toxicological data to support environmental risk assessment and guide green chemical design. The importance of chemical toxicity data for human health and ecological risk assessment, trends of available chemical toxicity data, details of the common structural features associated with different toxicity endpoints, and applications of toxicological big data in toxicity prediction combined with artificial intelligence are described and discussed. Additionally, based on the systematic collection and analysis of the current toxicity data, a reorganized toxicological databank is provided to cover a wider range of organic chemicals and tested species. It is expected that this work can contribute to the study of organic structural toxicity, chemical toxicity prediction, environmental risk assessment, and safer chemical design. [ABSTRACT FROM AUTHOR]

Herein, a gold nanoparticles/graphene aerogels (AuNPs/GAs) modified electrochemical biosensor with catalytic hairpin assembly (CHA) and Y-shaped DNA nanostructure dual-signal amplification approaches for ultrasensitive microRNA-21 (miR-21) detection was successfully constructed, which displayed an ultra-wide detection linear range from 5 fM to 50 nM, as well as a relatively low detection limit (LOD) of 14.70 aM (S/N = 3). Furthermore, the sensing strategy had excellent specificity among highly homologous miRNA family members and exhibited satisfactory analytical performance for miRNA detection. [ABSTRACT FROM AUTHOR]

A novel ionic bi-functional ligand of L2 containing a phosphine and a Lewis acidic phosphonium with I− as the counter-anion was prepared and fully characterized. The molecular structure indicated that the bi-functionalities in L2 were well retained without the incompatibility problem for quenching of the acidity of the phosphonium cation by the Lewis basic phosphine fragment or the anionic I− when the incorporated phosphine fragment and the Lewis acidic phosphonium were strictly located in the confined cis-positions. The co-catalysis over L2–Rh(acac)(CO)2 in the ways of synergetic catalysis and sequential catalysis was successfully fulfilled for one-pot hydroformylation–acetalization, which proved not to be the result of the simple mixture of the mono-phosphine (L4) and the phosphonium salt (L4′). In L2, the phosphonium not only acted as a Lewis acid organocatalyst to drive the sequential acetalization of aldehydes, but also contributed to the synergetic catalysis for the preceding hydroformylation through stabilizing the Rh-acyl intermediate with the phosphine cooperatively. The L2-Rh(acac)(CO)2 system is also generally applied to hydroformylation–acetalization of a wide range of olefins in different alcohols. Advantageously, as an ionic phosphonium-based ligand, L2 could be recycled for 7 runs with Rh(acac)(CO)2 together in RTIL of [Bmim]BF4 without obvious activity loss or metal leaching. [ABSTRACT FROM AUTHOR]

The combination of phosphine-ligated Pd catalysis and phosphenium(v) Lewis acid catalysis has been developed for the carbonylative Sonogashira reaction using phosphino-phosphenium salts (L1–L4) as bifunctional ligands, in which the Lewis acidic phosphenium(v) cations can form secondary bonds with O atoms (in C=O) to cooperatively stabilize Pd–acyl intermediates. [ABSTRACT FROM AUTHOR]

A "two-in-one" strategy was employed to construct 3D-COFs for the first time. Based on this strategy, a 3D-Flu-COF could be readily synthesized in various simplex organic solvents. Benefitting from the non-conjugated structure, the 3D-Flu-COF showcased excellent acidichromic sensing performance with good sensitivity, reversibility and naked eye visibility. [ABSTRACT FROM AUTHOR]

In this study, we synthesized MOF-derived TiO2 modified with g-C3N4 nanosheets by using a mechanical agitation method with further heat treatment. The effect of g-C3N4 nanosheet incorporation ratio on the photocatalytic performance of the composites was studied. The physical and optical properties of the as-synthesized specimens were well characterized via multiple analytical techniques. The visible-light photocatalytic performance was evaluated using RhB as a model organic pollutant. Compared with pure TiO2 and g-C3N4, the g-C3N4/TiO2 photocatalysts exhibited superior visible-light photocatalytic activities. The optimized mass fraction of g-C3N4 is 1%, namely the g-C3N4 (1%)/TiO2 specimen, which exhibited the highest photocatalytic performance. Based on the trapped active species, N2 physisorption and photochemical experiments, the enhanced photocatalytic performance was ascribed to the accelerated separation rate of photogenerated charge carriers, the increased specific surface area, and the extended visible-light response range. Our current work demonstrated a potential route to develop high-performance photocatalysts in practical applications. [ABSTRACT FROM AUTHOR]

Organic–inorganic hybrids have drawn great attention for gas sensors due to their high sensitivity, good selectivity and acceptable stability at room temperature. There are two main approaches by which organic–inorganic hybrids convert gas information to electric or optical signals (vapochromism). Here, we have reported a new organic–inorganic hybrid PEA2MnBr4 for humidity detection by luminescent visible chromism. PEA2MnBr4 single crystals were grown by the solution method and determined by single-crystal X-ray diffraction. Luminescent humidity chromism was found on PEA2MnBr4 from green emission at the water-desorption state to pink emission at the water-adsorption state within 18 s at a relative humidity of 38% RH. This obviously visible chromism was further used to check the water content in toluene with a low detection limit between 0.02 and 0.05 vol%. [ABSTRACT FROM AUTHOR]

Because of the contradiction between the safe thickening time of cement slurry and over-retarding at the top in the cementing of a long sealing section with large temperature difference, we synthesized a quaternary copolymerization retarder with 2-acrylamide-2-methyl propane sulfonic acid (AMPS), acrylic acid (AA), diallyl dimethyl ammonium chloride (DMDAAC) and allyl polyoxyethylene ether (APEG). The structure of the retarder was characterized by FTIR and 1H NMR and its thermal stability was tested by TG-DSC. The results showed that the molecule contained the designed functional groups, the initial pyrolysis temperature was 364 °C, and its performance was stable in the temperature range of 90–150 °C. There was no "bulge" or "step" on the thickening curve, and the thickening time could meet the safety requirements of pumping at high temperatures. It can also ensure the development of compressive strength of cement in the low-temperature section and has excellent temperature adaptability. Through the study of its retardation mechanism, it was found that the retarder molecules formed an adsorption layer of a certain thickness on the surface of cement particles by adsorption, and the concentration of Ca2+ in the solution was reduced by complexation, so as to prevent cement hydration and prolong the thickening time. Generally speaking, the large temperature difference adaptability of retarders was mainly manifested in the decrease of molecular adsorption capacity and performance at low-temperature and the improvement of molecular adsorption capacity and performance at high-temperature. [ABSTRACT FROM AUTHOR]

MnV2O6 is a promising anode material for lithium ion batteries with high theoretical specific capacity, abundant reserves and inexpensive constituent elements. However, in the process of lithization and de-lithization, the MnV2O6 anode material will form an amorphous phase, leading to collapse of its original layered structure; this greatly decreases its lithium storage capacity and specific capacity and affects its long-term cycle performance. In this study, 2D accordion-like MnV2O6 nanosheets with Co-doping are obtained via a hydrothermal route. The cobalt ions partially replace the positions of the manganese ions, and the emergence of Co3+ ions is inferred to induce the formation of a built-in electric field in the electrode to enhance the electrochemical behaviour of MnV2O6, presenting a high capacity of 1005.9 mA h g−1 after hundreds of cycles. The capacitive contribution to the total capacity is investigated to obtain insight into the kinetic analysis of its electrochemical behaviour. This study sheds light on an effective strategy to obtain excellent electrochemical behavior of MnV2O6-based materials and other transition metal oxides as electrodes for lithium storage. [ABSTRACT FROM AUTHOR]

Hydrophilicity greatly limits the application of ZnO in catalysis, sensing, energy conversion and other applications. There is an extremely urgent need to prepare superhydrophobic ZnO. In this study, a novel superhydrophobic ZnO flower-like nanostructure with petals 10 μm in length and 2 μm in width was obtained by a combination of hydrothermal and single dip-coating methods on nickel foam. Porous flower-like ZnO nanostructures were synthesized on the nickel foam substrate by an economical hydrothermal method combined with subsequent calcinations. The rough surface caused by acid treatment and the cross-growth of the petals increased the stability of the flower-like ZnO and the binding force between the ZnO layer and the nickel wire. Decomposition of the ZnO precursor released CO2 and H2O, leaving uniform holes in the ZnO petals. After hydrophobic treatment with PFAS, the contact angle was 154° and the sliding angle was approximately 2°, indicating that the surface changed from hydrophilic to superhydrophobic. The superhydrophobic surface could withstand a temperature of 350 °C in an air atmosphere, indicating that the superhydrophobic surface has good thermal stability. The ZnO flower-like nanostructure can be potentially used in microwave absorption, electrochemical sensing, heterogeneous catalysis and lithium-metal batteries. This work provides a new method for the practical fabrication of superhydrophobic surfaces. [ABSTRACT FROM AUTHOR]

Correction for ‘Low temperature, rapid and controllable growth of highly crystalline ZnO nanostructures via a diluent hydrolytic process and its application to transparent super-wetting films’ by Huijie Wang et al., CrystEngComm, 2018, 20, 7602–7609. [ABSTRACT FROM AUTHOR]

A highly enantioselective synthesis of β-hydroxysulfones from inexpensive and readily available terminal alkynes and sodium sulfinates via a consecutive one-pot reaction in an aqueous medium under mild conditions is described. The intermediates, β-keto sulfones, generated from an aerobic oxysulfonylation of terminal alkynes and sodium sulfinates catalyzed by an iron salt in MeOH/H2O (v : v = 3 : 1) at 50 °C, were subsequently reduced by a Ru-catalyzed asymmetric transfer hydrogenation with HCOONa as a hydrogen source. A variety of chiral β-hydroxysulfones were obtained in good yields and up to 99.9% ee values. This one-pot process could be easily scaled up for gram-scale synthesis. [ABSTRACT FROM AUTHOR]

A highly selective and reproducible electroanalysis strategy was developed for probing histidine using tetrahedral copper metal organic frameworks. It can facilitate His detection through the stable "turn-on" signal output of solid-state CuCl electrochemistry at a potential approaching zero, with the level down to about 25 nM in blood. [ABSTRACT FROM AUTHOR]

Lead halide two-dimensional (2D) nanoplatelets (NPLs) have attracted intense interest due to their unique optoelectronic properties. However, environmental friendly lead-free 2D perovskite NPLs are highly desirable in terms of application. Herein, all-inorganic Cs3Bi2Br9 perovskite NPLs are synthesized for the first time via the hot injection method. The Cs3Bi2Br9 NPLs are parallelogram-shaped and exhibit an extremely sharp first exciton peak which blue-shifts substantially with respect to their bulk bandgap. The formation of Cs3Bi2Br9 NPLs is determined by the layered feature of Cs3Bi2Br9 crystalline structure and the shape of parallelogram is the reflection of the trigonal nature of Cs3Bi2Br9 crystal. The large blue-shift and extremely sharp first exciton peak are due to large exciton binding energy and quantum confinement in the Cs3Bi2Br9 NPLs and large exciton binding energy in Cs3Bi2Br9 crystal. The Cs3Bi2Br9 NPLs grow anisotropically from monodispersed parallelogram-shaped nuclei via Ostwald ripening, demonstrated by ex situ TEM investigation. Anion-exchange was used to effectively adjust the composition of the Cs3Bi2Br9 NPLs. Additionally, the Cs3Bi2Br9 NPLs exhibit excellent stability to air and illumination due to the robust crystal, BiOBr passivation and oleylamine and oleic acid co-passivation. [ABSTRACT FROM AUTHOR]

A solid-state fluorimetric strategy has been developed using test strips coated with Q-graphene-loaded metal–organic framework nanocomposites featuring water-triggered fluorescence turn-on. It can facilitate the real-time evaluation of trace water in organic solvents, with the level down to about 0.015% in alcohol. [ABSTRACT FROM AUTHOR]

Five new homodinuclear lanthanide complexes with the general formula [(acac)4Ln2(L)] (Ln3+ = Dy3+ (1), Tb3+ (2), Ho3+ (3), Er3+ (4), and Gd (5)) were synthesized by one-pot [2 + 2] condensation of 2,6-diformyl-4-methylphenol and 1,3-diaminopropane in the presence of various lanthanide acetylacetonates. The eight-coordinate Ln(iii) centre adopts a slightly distorted square antiprism geometry with D4d symmetry. Theoretical analysis and magnetic measurements reveal that the corresponding Dy complex 1 exhibits slow magnetic relaxation behavior, characteristic of a typical SMM with the intramolecular ferromagnetic Dy3+…Dy3+ interaction. [ABSTRACT FROM AUTHOR]

In recent years, there has been increasing interest in fabricating noble metal nanoparticles using bio-templates for various biomedical applications, with the hope of finding a low cost method for their construction by a fairly simple and environmentally friendly synthetic strategy. In this study, novel self-assembled superstructures, namely, bacitracin–platinum nanoparticles (Bac–PtNPs), were designed and prepared under mild conditions. Bacitracin has two purposes: self-assembly to form a specific structure and the recognition of platinum nanoparticles, providing nucleation sites to form the nanomaterials. The spherical chain-like Bac–PtNPs were synthesized by the incubation of bacitracin and PtCl4 aqueous solutions at pH 2.0 for 24 h. The nanoparticles were face-centered cubic (fcc) crystalline, which were stable in aqueous solution. Functional groups such as –NH and –OH on the bacitracin surface serve as binding moieties and mediated the initial growth of the Pt nanoparticles. Anti-tumor effects exhibiting excellent therapeutic efficacy were confirmed both in vitro and in vivo. This study introduces a simple and effective platform for the design and preparation of the antitumor nanocomplexes, highlighting their potential applications in the biomedical field. [ABSTRACT FROM AUTHOR]

Four half-sandwich type mononuclear lanthanide crown ether complexes with the formula [Ln(12-crown-4)(NO3)3] (Ln3+ = Dy3+ (1), Tb3+ (2), Ho3+ (3), and Er3+ (4); 12-crown-4 = 1,4,7,10-tetraoxacyclododecane) were successfully synthesized and structurally characterized. Ac magnetic susceptibility measurements reveal that dysprosium complex 1 behaves as a typical single-ion magnet, while solid state photoluminescence studies show that complexes 1 and 2 have the respective lanthanide(iii) luminescence characteristics. [ABSTRACT FROM AUTHOR]