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Capacitive deionization is a promising solution for freshwater production with Ti3C2Tx emerging as a momentous electrode material. Here, highly porous 3D nitrogen-doped Ti3C2Tx (3D-N-Ti3C2Tx) is developed by using electropositive melamine to electrostatically induce electronegative Ti3C2Tx nanosheets to be reconstructed to alleviate the severe stacking problem of Ti3C2Tx layers. 3D-N-Ti3C2Tx has a large specific surface area (129.48 m2 g−1) and pore volume (0.372 cm3 g−1), exposing numerous ion adsorption sites. Also, 3D-N-Ti3C2Tx achieves nitrogen doping, which greatly improves the hydrophilicity and electrical conductivity. With the combined advantages of a three-dimensional structure and nitrogen doping, 3D-N-Ti3C2Tx achieves a specific capacitance of 101.9 F g−1 in 1 mol L−1 NaCl solution and demonstrates fantastic desalination performance with a high desalination capacity of 31.51 mg g−1, surpassing those of the majority of reported Ti3C2Tx electrodes, and outstanding desalination cycling stability in 500 mg L−1 NaCl solution at 1.2 V. This work significantly contributes to the advancement of Ti3C2Tx electrode material in CDI. [ABSTRACT FROM AUTHOR]

Casein/starch composites are shown to act as potential candidates for binders of symmetric carbonaceous electrodes used in the capacitive deionization (CDI) of water. Casein and potato-starch biopolymers are cheap and environmentally friendly and may be implemented throughout a green process to obtain a carbonaceous CDI electrode using sole water as a solvent. It was found that among the different starch/casein mass ratios considered in this study (0 : 1, 1 : 1, 2 : 1, 1 : 2, 1 : 4 and 1 : 0), the ratio 1 : 2 resulted in an optimal CDI performance corresponding to 12.7 mg g−1, 50% and 1.01 W h g−1 for salt adsorption capacity, charge efficiency, and specific energy consumption, respectively. The outstanding performance observed is attributed to the formation of a binder with a hydrophilic mesoporous network carrying inherent positive and negative charges throughout the internal surface area, inducing both anion and cation-exchange membrane characteristics in the binder layer. For the optimal binder composition, the latter network possesses a dominant pore diameter of 4.65 nm, while the dominant pore diameter is less than 3.00 nm for the other samples, eventually enhancing ion species mass transfer through the polymer matrix. [ABSTRACT FROM AUTHOR]

Ru(II) complexes with polypyridyl ligands (2,2′-bipyridine = bpy, 1,10-phenanthroline = phen) play a central role in the development of photocatalytic organic reactions. In this work, we synthesized four mixed-ligand [Ru(phen)(bpy)2]2+-type complexes (Ru-Pcat-A) bearing two phosphonate substituents P(O)(OH)(OR) (R = H, Et) attached to the phen core at positions 3,8 (Ru-3,8PH and Ru-3,8PHEt) and 4,7 (Ru-4,7PH and Ru-4,7PHEt) of the heterocycle in high yields (87–99%) and characterized them using spectral methods. Single crystal X-ray diffraction was employed to determine the coordination mode of the ditopic phen ligand in Ru-4,7PH. This complex exists as the neutral species and forms a 1D hydrogen-bonded framework in the crystals. The light absorption characteristics were found to be similar for all complexes prepared in this work. However, the emission maxima in aqueous solutions were significantly affected by the substitution of the heterocycle, ranging from 629 nm for Ru-4,7PH to 661 nm for Ru-3,8PHEt. The emission quantum yields in Ar-saturated deionized water showed a strong dependence on the substitution pattern of the phen ligand, with maximal values reaching approximately 0.11 for Ru-4,7PHEt and Ru-4,7PH, which is twice as high as that of the classical [Ru(bpy)3]2+ complex (Ru-bpy). The photocatalytic performance of Ru-Pcat-A was investigated using visible light photoredox catalytic transformations of tertiary amines. With Ru-Pcat-A, we achieved the phosphonylation of N-aryl-1,2,3,4-tetrahydroisoquinolines (THIQs) and cyanation of THIQs and N,N-dimethylaniline in methanol, while a mixture of nitromethane/methanol (1 : 1 v/v) proved to be the optimal solvent for conducting the nitromethylation of THIQs. In the majority of the studied reactions, Ru-4,7PHEt exhibited greater efficiency compared to Ru-bpy, and it could be easily separated from the products using water extraction and reused in the next catalytic cycle. We successfully performed seven consecutive nitromethylation and phosphonylation of N-phenyl-1,2,3,4-tetrahydroisoquinoline using the recycled homogeneous photoredox catalyst. [ABSTRACT FROM AUTHOR]

Herein, a 3D SERS substrate based on nickel foam (NF) and silver nanoparticles (AgNPs/NF 3D SERS) was synthesized using vacuum-assisted thermal evaporation deposition. The performance of the AgNPs/NF 3D SERS substrate was investigated using rhodamine 6G (R6G) as a probe molecule at different AgNP deposition levels. The highest sensitivity of the substrate with a limit of detection (LOD) of 10−9 M and an enhancement factor (EF) of 1.56 × 106 was achieved when the optimal amount of AgNPs was reached. Moreover, the use of R6G at 10−6 M concentration as the probe molecule ensured the relative standard deviation (RSD) of 9.2% for the AgNPs/NF 3D SERS substrate, and its SERS performance hardly decreased after 30 days of placement at room temperature, which evidenced that the prepared SERS substrate had favorable stability and repeatability. Finally, the substrate was used to analyze carbendazim in deionized and river water in two different environments. The results revealed that the LOD of CBZ was as low as 10−7 M under both conditions, and there was a good linear relationship between the CBZ concentration and the SERS signal intensity (R2 = 0.955 and 0.927, respectively), which demonstrated the great potential of AgNPs/NF 3D SERS substrates for pesticide residue identification in practical analysis. [ABSTRACT FROM AUTHOR]

Aqueous zinc–sodium hybrid batteries with a Prussian blue cathode have been extensively studied in recent years. However, less research has been conducted on low-cost ferric ferricyanide (FeFe(CN)6) cathode materials. Considering that both Zn2+ and Na+ can be reversibly embedded in FeFe(CN)6 crystals, here we focus on mixed electrolytes with different concentrations of ZnSO4 and Na2SO4 in deionized water to explore the preference of FeFe(CN)6 towards Zn2+ and Na+. As a result, by using 0.1 M ZnSO4 + 1 M Na2SO4 electrolyte, a superior battery performance is obtained, which reveals that the co-function of Zn2+ and Na+ in this electrolyte promotes Zn//FeFe(CN)6 cells to exert a superior specific capacity. In this work, FeFe(CN)6 is synthesized by a co-precipitation method and is analyzed by XRD, SEM, etc., and then used as the cathode material in Zn–Na hybrid batteries. Cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) tests show that FeFe(CN)6 in 0.1 M ZnSO4 + 1 M Na2SO4 electrolyte delivers the highest discharge/charge capacities of 165.2/165.9 mA h g−1 (theoretical specific capacity: 212.2 mA h g−1) at a 0.1 C current density, with good capacity retention of 84% after 200 cycles at 15 C, outperforming many of the reported Zn–Na hybrid cells. [ABSTRACT FROM AUTHOR]

In this work, copper-based halides Cs2CuCl4, Cs2CuBr4 and mixed-halides Cs2CuCl2.8Br1.2, Cs2CuCl2Br2 and Cs2CuCl1.2Br2.8 single crystals were grown via the evaporation method using deionized water as a solvent. The structure and actual element component of the Cs2Cu(Cl, Br)4 crystals were studied using XRD and EDS. The halides of Cs2Cu(Cl, Br)4 exhibit both good light absorption and PL performance. The absorption peaks related to LMCT electron transition bands were observed, and the tunable band gap was obtained by adjusting the Br−/Cl− ratio. PL spectra show purple, blue, and green luminescence, and the luminescence mechanism was analyzed. Our study indicates that the Cs2Cu(Cl, Br)4 halides have application prospects in optoelectronic devices. [ABSTRACT FROM AUTHOR]

Capacitive deionization is an emerging water desalination technology for industrial applications. Recent advancements in electrode design and system development have led to the reporting of ultra-high salt adsorption performance, benefiting its potential application in agricultural water treatment at a potentially low cost. In this study, we provide a comprehensive summary of the porous electrode design strategy to achieve ultra-high ion adsorption performance, considering factors such as experimental parameters, chemically tuned material properties, redox chemistry and smart nanoarchitecture for future electrode design. Furthermore, we endeavor to establish a correlation between capacitive deionization (CDI) technology and its applicability in the agricultural sector, specifically concentrating on water treatment with an emphasis on undesirable ions associated with salinity, hardness, and heavy metals, to achieve harmless irrigation. Additionally, to ensure the efficient and cost-effective application of CDI systems in agriculture, a thorough overview of the literature on CDI cost analysis is presented. By addressing these aspects, we anticipate that ultra-high salt adsorption CDI systems hold great promise in future agricultural applications. [ABSTRACT FROM AUTHOR]

C/Ti3C2/g-C3N4 hollow microspheres (HM) were prepared by the template method to construct Ti3C2/g-C3N4 Schottky junctions on the spherical surface. The C/Ti3C2/g-C3N4 HM Schottky junctions presented excellent photocatalytic properties for producing hydrogen and decomposing organic pollutants simultaneously from wastewater without the addition of a sacrifice agent. The research revealed that the built-in electric field between g-C3N4 and Ti3C2 MXene could decrease the charge transfer resistance, leading to efficient photo charge separation, and the organic pollutant tetracycline (TC) could act as a sacrifice agent for splitting water. The H2 evolution rate of the CN-TCM-3 sample in deionized water with a sacrifice agent reached 105.4 μmol g−1 h−1, and the TC removal rate reached 100% within 120 min. The hydrogen production efficiency of CN-TCM-3 in the natural water of Slender West Lake without or with TC as a sacrifice agent was 2.3 μmol g−1 h−1 and 3.2 μmol g−1 h−1, respectively. The addition of TC improved the hydrogen production efficiency by 39%. This research indicated that the C/Ti3C2/g-C3N4 HM Schottky junctions could be a potential photocatalyst for producing hydrogen and decomposing organic pollutants in sewage simultaneously. [ABSTRACT FROM AUTHOR]

Transition-metal sulfides (TMSs) have indeed drawn dramatic interest as a potential species of electrocatalysts by virtue of their unique structural features. However, their poor stability and inherent activity have impeded their use in electrocatalytic water splitting. Here, we provide a rational design of a hierarchical nanostructured electrocatalyst containing CeOx-decorated NiCo-layered double hydroxide (LDH) coupled with Ni3S2 protrusions formed on a Ni foam (NF). Specifically, the as-prepared electrocatalyst, denoted as Ni2Co1 LDH-CeOx/Ni3S2@NF, presents only 250 and 300 mV overpotential at ±100 mA cm−2, respectively, along with the Tafel slope values of 92 and 52 mV dec−1, as well remarkable long-term life for water splitting in an alkaline electrolyte. Based on systematic experiments and theoretical analysis, the superior electrocatalytic property in terms of Ni2Co1 LDH-CeOx/Ni3S2@NF can be imputed to the following reasons: the porous framework of Ni3S2@NF provides a largely surface area and high conductivity; the NiCo LDH nanosheets provide enriched active sites and favorable adsorption ability; the oxygen-vacancy-rich CeOx optimizes the electronic configuration. Overall, these factors work synergistically to expedite the catalytic kinetics of splitting water. Our work concentrates on a rational interface to devise efficient, multifunctional, and serviceable electrocatalysts for future applications. [ABSTRACT FROM AUTHOR]

Ciprofloxacin (CIF) is a powerful synthetic antibiotic usually used for chest, skin, and bone infections when the patients have resisted other antibiotics. However, ciprofloxacin has a weakness in terms of solubility, especially in water between pH 6 and 8. Therefore, we propose the formation of novel salt forms of ciprofloxacin with oxalic acid (OXA) in order to alter and improve the solubility. Liquid assisted grinding (LAG) was used as a pre-screen for salt or co-crystal formation with nine candidates for the co-former based on known synthons. The solid-state characterization results confirmed that from these nine candidates, CIF is able to form hydrated salts only with oxalic acid (OXA). Interestingly, CIF-OXA forms hydrated salts with three different stoichiometric forms with different ratios between CIF and OXA. The appearance of hydrated salts with different stoichiometry is caused by the diversity of protonated/deprotonated forms in the OXA molecule, including OXA, OXA−, and OXA2−.The precise molecular structures of the products were confirmed by SC-XRD, which found that the three products are CIF6+OXA32−·2H2O (form A), CIF2+OXA1OXA12−·2H2O (form B), and CIF2+OXA1OXA2−·2H2O (form C). Furthermore, all product forms reveal enhanced solubility in deionized water approximately 38.5, 66.0, and 41.0 times for form A, B, and C with respect to pure CIF. [ABSTRACT FROM AUTHOR]

As a promising continuous desalination technology, flow electrode capacitive deionization (FCDI) has received considerable attention. However, poor conductivity and dispersion of the traditional active carbon (AC) flow-electrode limit the properties of FCDI. In order to achieve excellent desalination performance, a flow electrode with good dispersion, low resistance, and high salt adsorption capacity is essential. In this study, nitrogen-doped porous carbon (NPC) was synthesized through one-step pyrolysis process of ethylenediamine tetraacetic acid tetrasodium (Na4EDTA). The prepared NPC material showed a high specific surface area (1168.4 m2 g−1), appropriate nitrogen and oxygen doping, excellent hydrophilicity and low resistance. At 1.2 V applied voltage, the desalting experiments showed that the FCDI system based on a NPC flow electrode exhibited a higher average salt removal rate of 0.0459 mg cm−2 min−1, and the salt adsorption capacity (148.93 mg g−1) based on the NPC flow electrode was about 2.3 times larger than that of AC. Furthermore, after continuous desalination cycling for long periods of time, the salt removal efficiency and average salt removal rate remained stable. The results of this study may be useful for the future exploration of high performance electrode materials for FCDI systems. [ABSTRACT FROM AUTHOR]

The nanoscale Li2Mn0.8Ni0.2SiO4/MnO2 composite was successfully prepared via a two-step method. Firstly, by the preparation of MnO2 nanoparticles through an oxidation-reduction reaction; secondly, by synthesizing Li2Mn0.8Ni0.2SiO4 using an EDTA-assisted sol–gel method; finally, the two nanoparticles mixed together by hand milling to form the nanocomposite. The synthesized nanoparticles were characterized using several techniques. The nanocomposite presents a well-developed orthorhombic crystal structure with a Pmn21 space group, although there are small impurities of MnO and Li2SiO3. The BET surface area measurements indicate that all the prepared materials are mesoporous. The effect of nanoscale MnO2 on the electrochemical properties of the Li2Mn0.8Ni0.2SiO4 nanomaterials was evaluated. The composite (denoted as (LMNS/M2) exhibited a specific capacity of 962.4 C g−1 at the current density of 2 A g−1. Furthermore, a hybrid device using this composite as a cathode and commercial activated carbon (AC) as an anode was fabricated to examine the practical aspects of the novel electrode, which conducted a specific energy of 38.1 W h kg−1 at a specific power of 938.4 W kg−1. It preserved a capacity of 84% after 2000 cycles. Li2Mn0.8Ni0.2SiO4/MnO2 is a promising candidate for high-efficiency energy storage electrode materials for supercapacitor applications because of its superior performance and ease of preparation. The obtained results confirm the excellent electrochemical performance of the electrode as a promising electrode for energy storage applications. [ABSTRACT FROM AUTHOR]

As a new type of carbon nitride material with high nitrogen content, g-C3N3 has promising application potential in the fields of photocatalysis, electrochemistry and energy storage. In this study, we found that g-C3N3 can be dissolved in concentrated sulfuric acid at room temperature to form a true thermodynamic solution for the first time, and the g-C3N3 can be reversibly precipitated successfully by adding deionized water to the solution. The solution with a high concentration of 300 mg ml−1 exhibits good stability even at −40 °C. The dissolution phenomenon of g-C3N3 in concentrated sulfuric acid and the solution stability at low temperature will pave the way for its potential applications. [ABSTRACT FROM AUTHOR]

Cr(VI) in wastewater poses a serious threat to human health, so there is an urgent need to remove it using a cost-effective way. Herein, we report a composite electrode material of homemade paulownia biochar and MoS2 (PBC@MoS2) for the efficient and selective removal of Cr(VI) from wastewater. PBC@MoS2 has an excellent ability to selectively remove Cr(VI) by electrosorption under the coexistence of different anions and cations (385.74 mg g−1 at voltage = 1.2 V, spacing = 1 mm, and initial concentration = 60 mg L−1). It can achieve 98.75% desorption and regeneration of the electrode within 1 h, and after 5 cycles of adsorption/desorption, it still maintains 97.02% of the original adsorption capacity. The characterization analysis shows that the removal process of Cr(VI) has both electrosorption and reduction effects, which can reduce 85.4% of the highly toxic Cr(VI) to the less toxic Cr(III). This is facilitated by the large specific surface area and special two-dimensional sheet structure of PBC@MoS2 composites. The results of this work can provide data support for the design of high-performance CDI systems for the removal of Cr(VI) from wastewater. [ABSTRACT FROM AUTHOR]

Metal–organic framework (MOF) derived porous carbon materials have been widely applied as active materials for supercapacitors due to their large specific surface area and ordered pore structure. This paper presents a facile and effective strategy to regulate the morphology of a zinc-based metal–organic framework (Zn-trimesic acid, Zn-BTC) by adjusting the ethanol content in a solvent, which can effectively change the pore structure of Zn-BTC derived porous carbon (PC). The optimal PC prepared in 50% ethanol displays a rodlike structure with a large specific surface area (SSA) of 1930 m2 g−1 and an average pore size of 2.9 nm. This material shows an excellent rate performance with 78.8% capacitance retention when the current density increases from 1 A g−1 to 100 A g−1 and outstanding electrochemical stability with only 2.2% decline of capacitance after 200 000 cycles at 50 A g−1. Moreover, the assembled symmetrical capacitor shows a high energy density of 16.09 W h kg−1 at 698 W kg−1 and 11.89 W h kg−1 at a high power density of 41.56 kW kg−1. This method would provide a new pathway for the preparation of carbon materials with an adjustable pore size for high-performance supercapacitors. [ABSTRACT FROM AUTHOR]

Nano-drug carriers have been widely used in chemotherapy to improve the efficacy of chemotherapeutic drugs. Polymer nano-carriers have greater potential for the enrichment of chemotherapeutic drugs at the target tumor site and controlled release. Herein, a series of amphiphilic copolymers (ITT) was synthesized via melt polymerization with a ROS-cleavable thioketal cross-linker, imidazole groups, and polyethylene glycol-conjugated triphenylphosphonium (PEG-TPP) segments; the actual proportions of the imidazole groups to the PEG-TPP segments were 5.2 : 1, 2.6 : 1, and 1.8 : 1, respectively. The amphiphilic copolymers could self-assemble into cationic micelles with hydrophobic imidazole groups as the core and hydrophilic PEG-TPP segments as the shell in deionized water. The cationic micelles with an average particle size of 124.6–187.3 nm showed a drug loading content (DLC) of 5.65–6.10%. In vitro release studies revealed the pH/ROS dual-responsiveness of the DOX-loaded ITT micelles, and the release behavior of DOX from the micelles strongly depended on the content of imidazole groups in the ITT micelles. Typically, the release of the encapsulated DOX was 27.2%, 30.0%, and 34.1% from DOX-loaded ITT-1 micelles in PBS (pH 6.5) containing 0, 100, and 500 μM H2O2, respectively. The release of the encapsulated DOX was 20.3%, 27.2%, and 42.5% from DOX-loaded ITT-1 micelles in PBS (pH 7.4), PBS (pH 6.5), and PBS (pH 5.0), respectively. The DOX-loaded micelles effectively inhibited the growth of 4T1 cells through being internalized into the 4T1 cells and releasing DOX into the mitochondria, with a cell viability of less than 65% when the DOX concentration was 2.5 μg mL−1. This work presents a novel mitochondria-targeting and pH/ROS-responsive polymer nanocarrier for potential chemotherapy applications. [ABSTRACT FROM AUTHOR]

Violet phosphorus, a non-metallic elemental layered structure, has not been reported as a photocatalyst due to the lack of its resources. An excellent photocatalytic H2 evolution rate of 675 ± 109 μmol h−1 g−1 with high stability has been achieved by the violet phosphorus simply dispersed in deionized water with addition of 1.0 wt% of co-catalyst Pt, which is much higher than that obtained from black phosphorus. The H2 evolution rate was observed to reach values as high as 553 μmol h−1 g−1 with addition of 0.5 wt% co-catalyst Pt. [ABSTRACT FROM AUTHOR]

The improvement of solubility and dissolution properties are the focus of research on poorly water-soluble APIs. Cocrystallization, which offers a different approach to modify properties of APIs, has gained considerable interest recently. Herein, we designed and synthesized two novel nomegestrol acetate (NA) cocrystals using 2,5-dihydroxybenzoic acid (DA) and 4-hydroxybenzoic acid (PA). Both cocrystals were characterized by single-crystal X-ray diffractometry (SCXRD), powder X-ray diffractometry (PXRD), Fourier transform infrared spectroscopy (FT-IR), and differential scanning calorimetry (DSC). Powder dissolution studies indicated that the concentrations of NA–DA and NA–PA at 3 h are approximately 5 and 4 times that of NA in deionized water, respectively. These successful results imply that the cocrystallization strategy is an effective means to improve the solubility of NA. [ABSTRACT FROM AUTHOR]

We propose an aqueous copper battery via Cu2+/Cu+ and Cu3+/Cu2+ redox conversion chemistry on an activated carbon (AC) electrode enabled by a 30 m ChCl + 1 m CuCl2 electrolyte, where Cu3+/Cu2+ redox promotes the discharge capacity by ∼50 mA h g−1 at ∼1.0 V vs. Ag/AgCl with stable cycling. [ABSTRACT FROM AUTHOR]

Benefiting from its large specific surface area and hierarchical pore structure, biomass-derived porous carbon is widely used as an electrode material for energy storage devices. In this research, ginkgo leaves are used as a precursor and KOH as an activator to prepare porous carbon (KGL). The anthraquinone-type anionic dye molecule Alizarin red S (ARS) is anchored on porous carbon via two adsorption methods. ARS plays a crucial role in enhancing the electrochemical properties. KGL has larger adsorption capacity for ARS through electric field assisted adsorption compared with physical adsorption and more favorable electrochemical performance. KGL/ARS exhibits superior specific capacitance and rate performance because the redox reaction of ARS and porous carbon provides a stable conductive scaffold. The KGL/ARS-E5 electrode possesses a specific capacitance of 638.2 F g−1 at 1 A g−1 and the capacitance retention reaches 77.9% at 10 A g−1. The assembled asymmetric supercapacitor exhibits an energy density of 24.8 W h kg−1 at a power density of 801.4 W kg−1, and the capacitance retention of the device is 93.5% after 10 000 cycles. The research provides a novel method to achieve a combination of porous carbon and redox-enhanced materials as the electrode for supercapacitors and realizes the recycling of carbonous adsorbents containing the redox species. [ABSTRACT FROM AUTHOR]

Nanomaterials have attracted wide attention due to their promising characteristics in contrast to their bulk counterparts. However, techniques for their synthesis need to be explored further for their application in promising nanomaterial-based devices. Herein, a simple hydrothermal technique was developed for the synthesis of Fe3O4 nanoparticles utilizing nanoscale MnO2 as a template. It was found that the redox chemical conditions employed for the synthesis of nanostructured MnO2 are also applicable for the fabrication of Fe3O4 nanostructures. Subsequently, HRTEM, XRD and XPS analyses were conducted, which confirmed the presence of morphologically reduced Fe3O4. Furthermore, the electrochemical analysis revealed the promising supercapacitive behaviour of 590 F g−1 at a current density of 2.9 A g−1 for the as-synthesised MnO2/Fe3O4 nanocomposite. This high performance can be attributed to the favourable characteristics of the developed nanomaterial such as high specific surface area, abundant active sites and short diffusion paths for charges. [ABSTRACT FROM AUTHOR]

Copper supported porous silica–alumina hollow sphere catalysts were prepared using surfactant micelles to control the size distribution of interparticle spaces in the hollow sphere shells. The specific surface areas and pore volumes of the unsupported and copper supported hollow spheres tended to increase with increasing the ratio of deionized water to ethyl alcohol, and the active copper ion species was well dispersed on the hollow spheres as observed from the results of UV-vis spectroscopy. The copper supported hollow sphere catalyst prepared with a high ratio of deionized water to ethanol tended to show high activity for decomposition of nitrous oxide at reaction temperatures from 473 to 773 K. The present study also investigated the influence of the carbon number of surfactant molecules on the size of the interparticle spaces in the hollow sphere shells and the catalytic activity of the copper supported silica–alumina hollow spheres for decomposition of nitrous oxide. The size of interparticle spaces in the hollow sphere shells decreased with decreasing the carbon number, and the catalytic activity of the copper supported hollow sphere catalyst prepared with DTAB (carbon number = 12) showed the highest activity even though dispersion of the active copper ion species was not so high. These results indicate that the catalytic activity of the copper supported silica–alumina hollow sphere catalyst was influenced not only by the dispersion of the active copper species but also by the size of the interparticle spaces in the hollow sphere shells depending on the contact time of the nitrous oxide reactant with the active copper species. [ABSTRACT FROM AUTHOR]

An analytical method based on single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) was developed to study the release of ZnO nanoparticles from fabric face mask samples upon washing. Before application, the method was tested with commercial ZnO nanoparticle powders suspended in various types of dispersing media, including deionized water, detergent, 20% ethanol, and pure ethanol. These dispersing media were representative simulants normally used in migration studies of nanoparticles. The commercial ZnO nanoparticle suspensions were subjected to size analysis by SP-ICP-MS, and the results were in good agreement with those analyzed by transmission electron microscopy (TEM) and dynamic light scattering (DLS). Therefore, a method based on SP-ICP-MS was applied to examine the release of ZnO nanoparticles from four commercial fabric face mask samples upon washing in deionized water and 4% detergent for five washing cycles. The total content of Zn in fabric face mask samples was found to be approximately 60–100 μg g−1, as determined by conventional ICP-MS after acid dissolution of samples. With SP-ICP-MS, the released ZnO nanoparticles from fabric face mask samples upon washing in deionized water and 4% detergent were in the range of 100–200 nm. The released percentage of Zn from mask samples was approximately 0.25–1.17% in the first washing cycle in deionized water. However, higher percentages ranging around 1.97–3.12% were found for the release of Zn from mask samples in 4% detergent. This work illustrates the capability of SP-ICP-MS for providing information that can be useful for quality control of fabric face mask products. [ABSTRACT FROM AUTHOR]

Herein, a series of supramolecular self-assembled perylene diimide (PDI) nanomaterials by different solvents have been successfully prepared. Under visible-light irradiation, the self-assembled PDI supramolecular material pretreated by acetone (PDI (acetone)) exhibited superior photocatalytic degradation activity on bisphenol A (BPA) and Rhodamine B (RhB), which were 7.1 times and 4.2 times that of the monomeric PDI, respectively. The improved photo-degradation activity was mainly attributed to the rapid separation and transfer of the photogenerated carriers and π–π interaction between self-assembled PDI supramolecules. The analysis of free radical trapping experiments and ESR characterization together indicated that h+ and ˙O2− are the main active species to rapidly degrade pollutants. Meanwhile, this work also studied the influence of other solvents (e.g., deionized water, methanol, and ethanol) on the self-assembly process of monomeric PDI. In summary, this study provides a new strategy to develop highly efficient self-assembled PDI photocatalysts by different solvents. [ABSTRACT FROM AUTHOR]

Biomass-derived defective porous carbons with numerous superiorities have received widespread attention in capacitive deionization (CDI). However, the effective synthesis of defective carbons with ultrathin layered nanosheets and hierarchically porous structures from biomass is still a great challenge. Herein, we developed a sustainable molten salt-assisted acid exfoliation strategy for the production of highly accessible defect-rich carbon nanosheets with hierarchical porosity. Notably, the proposed method has successfully overcome the necessary alkali and template use, avoiding environmental pollution and energy consumption. Furthermore, the adopted acetic acid and molten salt meet sustainable development demands. The acetic acid can effectively exfoliate the aggregative polymer to the apparent 2D layered structure by preferentially hydrolyzing lotus and break numerous C–O groups. The subsequent molten salt-assisted pyrolysis can further crush the carbon framework, resulting in ultrathin nanosheets with abundant edges and porous defects. This favorable ultrathin layered and hierarchical structure guarantees accessible rich-defect features, which can not only benefit ion storage, but also provide sufficient diffusion pathways for ion penetration, contributing to excellent performance for CDI. Consequently, C-A/S displays a superior salt removal capability of 30.1 mg g−1 in 500 mg L−1 NaCl solution at 1.2 V with an outstanding regeneration capacity. Additionally, the capacitive contribution analysis and density functional theory also clearly demonstrate that the ultrathin 2D structure can remarkably expose more defect sites and enhance their accessibility. This work not only provides an efficient and sustainable strategy to improve the ion-adsorption capability of carbons, but also realizes the green recycling of biomass waste in environmental remediation. [ABSTRACT FROM AUTHOR]

Capacitive deionization (CDI) is an efficient new technology that can be used to remove charged pollutants. However, differences in the electrode selectivity for different ions limit its further application. Therefore, the electrosorption behavior and selectivity of four anions in a CDI system with activated carbon electrodes were investigated using mixed solutions. The results showed that the adsorption capacities and selectivities of the anions varied due to differences in their hydration energy and valence. The preferential electrosorption order was as follows: NO3− > Cl− > SO24− > phosphate (P). In addition, the competitive mechanism between different anions and P was studied. P competed with SO24− the most for electrosorption sites due to their spatial similarity. However, because the NO3− adsorption capacity was the highest, P had the lowest electrosorption selection coefficient when it coexisted with NO. Finally, the mechanism of the electrosorption selectivity was verified. The results indicated that the electrosorption selectivity of P was improved by decreasing the voltage to weaken the competition between P and other anions for sites and by adjusting the pH to optimize the hydration energy and electronegativity of P. This research may provide readers with a deeper understanding of electrosorption selectivity. [ABSTRACT FROM AUTHOR]

The rapid development of industrial technologies continuously increases the heavy metal pollution of water resources. Recently, portable electrochemical analysis-based devices for detecting heavy metal ions have attracted much attention due to their excellent performance and low fabrication costs. However, it has proven difficult to accommodate complex testing needs in a cost-effective manner. To address these limitations, we propose a new system for the in situ detection of heavy metals in wastewater using an organic light-emitting diode-based panel to display data in real time and Bluetooth to transmit data to a smartphone for rapid analysis. The fabricated device integrates an in situ signal analysis circuit, a Bluetooth chip, a photocured 3D-printed shell, and an electrode sleeve interface. In addition, a fully screen-printed functional electrode plate containing chitosan/PANi–Bi nanoparticle@graphene oxide multi-walled carbon nanotubes is utilized for the rapid detection of heavy metal ions. This device can perform wireless data transmission and analysis and in situ signal acquisition and processing. The sensor exhibits a high sensitivity (Hg2+: 88.34 μA ppm−1 cm−2; Cu2+: 0.956 μA ppm−1 cm−2), low limit of detection (Hg2+: 10 ppb, Cu2+: 0.998 ppm) and high selectivity during the detection of copper and mercury ions in tap water under non-laboratory conditions, and the results of real-time tests reveal that parameters measured in the field and laboratory environments are identical. Hence, this small, portable, electrochemical sensor with a screen-printed electrode can be effectively used for the real-time detection of copper and mercury ions in complex water environments. [ABSTRACT FROM AUTHOR]

The sensitive determination of selenium and copper is of importance for environmental monitoring and food safety. A stripping voltammetric determination of selenium and copper in water and selenium-rich foods was developed using hierarchical dendritic gold nanostructure (AuHD) modified glassy carbon electrodes (GCE). The AuHD thin films were electrodeposited potentiostatically onto the GCE from a solution containing 25 mM HAuCl4 and 0.1 M Na2SO4 at −0.6 V for 20 min. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) studies showed that the electrodeposited gold thin film shows a nanoforest-like morphology with a thickness of about 30–40 μm and a hierarchical dendritic structure with primary-, secondary-, and higher-order branches. Se(IV) and Cu(II) in a 0.1 M H2SO4 solution were determined by square-wave anodic stripping voltammetry using the AuHDs/GCE as the working electrode. Prior to anodic stripping, Se(IV) and Cu(II) were accumulated onto the working electrode surface at −0.2 V for 300 s. The stripping peak currents of Se(IV) at 0.81 V and Cu(II) at 0.31 V were positively correlated with the concentrations of Se(IV) and Cu(II) in a range of 50–700 nM. The limits of detection (3σ) for Se(IV) and Cu(II) were 1.4 nM and 3.7 nM, respectively. The accuracy of the method was verified by analysing certified water standard reference materials, and the results showed that the method has good accuracy and high precision. The method was used to determine selenium and copper in tap water, selenium-rich rice and selenium-rich eggs. The results were compared with those obtained by using inductively coupled plasma-mass spectrometry (ICP-MS) and found to be consistent with those of ICP-MS. The proposed method had the advantages of simplicity, rapidity, good reproducibility, and high sensitivity and it can be used for the analysis of real samples. [ABSTRACT FROM AUTHOR]

Despite having widespread application in the biomedical sciences, flow cytometers have several limitations that prevent their application to point-of-care (POC) diagnostics in resource-limited environments. 3D printing provides a cost-effective approach to improve the accessibility of POC devices in resource-limited environments. Towards this goal, we introduce a 3D-printed imaging platform (3DPIP) capable of accurately counting particles and perform fluorescence microscopy. In our 3DPIP, captured microscopic images of particle flow are processed on a custom developed particle counter code to provide a particle count. This prototype uses a machine vision-based algorithm to identify particles from captured flow images and is flexible enough to allow for labeled and label-free particle counting. Additionally, the particle counter code returns particle coordinates with respect to time which can further be used to perform particle image velocimetry. These results can help estimate forces acting on particles, and identify and sort different types of cells/particles. We evaluated the performance of this prototype by counting 10 μm polystyrene particles diluted in deionized water at different concentrations and comparing the results with a commercial Beckman-Coulter Z2 particle counter. The 3DPIP can count particle concentrations down to ∼100 particles per mL with a standard deviation of ±20 particles, which is comparable to the results obtained on a commercial particle counter. Our platform produces accurate results at flow rates up to 9 mL h−1 for concentrations below 1000 particle per mL, while 5 mL h−1 produces accurate results above this concentration limit. Aside from performing flow-through experiments, our instrument is capable of performing static experiments that are comparable to a plate reader. In this configuration, our instrument is able to count between 10 and 250 cells per image, depending on the prepared concentration of bacteria samples (Citrobacter freundii; ATCC 8090). Overall, this platform represents a first step towards the development of an affordable fully 3D printable imaging flow cytometry instrument for use in resource-limited clinical environments. [ABSTRACT FROM AUTHOR]

Biomass-derived porous carbon materials with superior wettability towards electrolytes are promising as electrodes for commercial supercapacitors (SCs), but the traditional synthetic processes result in serious environmental pollution and energy consumption. Herein, we propose an innovative closed-loop and scalable process for the production of B/N/O tri-doped superhydrophilic carbon derived from biomass. The adopted boric acid serves as a recyclable and inducing agent due to the reversible conversion between boric acid and boron oxide, further completing the closed-loop route for the production of biomass-derived superhydrophilic carbon. The as-made materials present a two-dimensional (2D) sheet-shaped structure and abundant pores; also, the B, N and O heteroatoms that are in situ introduced into the skeleton of carbon improve the surface hydrophilicity of the fabricated carbon. Benefitting from the synergistic effects of the hierarchical porous morphology, the superhydrophilicity and the multi-doping surface chemistry features of the resultant materials, the penetration, transport and interaction of electrolyte ions within the as-fabricated carbon electrodes would be highly improved. Thus, a favorable electrochemical performance of the supercapacitor is obtained, which can deliver a specific capacitance up to 296 F g−1@0.5 A g−1 in an aqueous electrolyte. This synthetic strategy with simple operation and mild conditions will be an efficient and potential way to accomplish the widespread application of biomass-derived superhydrophilic carbon in supercapacitors. [ABSTRACT FROM AUTHOR]

This study presents a rapid and low-cost amplicon detection method in which amplicons are attached to magnetic microbeads, suspended in deionized water, and subjected to a magnetic field on a hydrophilic surface resulting in the circular agglomeration of amplicon-conjugated microbeads, visible to the naked eye. [ABSTRACT FROM AUTHOR]

A new simple and rapid method was developed for the purification of Mg from carbonate samples, especially for calcite-rich carbonates. The proposed separation protocol consists of only two types of eluents (4 mol l−1 HNO3 and deionized water) based on 2 ml of DGA resin. 4 ml of HNO3 can effectively separate Mg from calcite-rich carbonates with a high yield within one hour. The Mg elution curve would not drift with different Mg and Ca loading onto the DGA resin. Ca/Mg ratios of the purified samples could be reduced by five orders of magnitude compared to the unpurified calcite-rich carbonate samples. The precision and accuracy of this new method have been evaluated by measurements of the synthetic solution, carbonate standard material, and ten readily available Chinese carbonate reference materials. All the Mg isotopic analytical results were, within analytical uncertainties, essentially identical with the data published previously. Therefore, the new method can be a great option for purifying Mg from carbonate samples for isotopic analysis. [ABSTRACT FROM AUTHOR]

Capacitive deionization is emerging as an energy-efficient technology for water desalination and research is continuing to find better electrode materials in order to achieve favorable properties and good desalination behavior. In this study, mesoporous carbon spheres (MCSs) were synthesized employing the hard template approach using mesoporous silica nanospheres (MSNs) with a narrow pore size distribution as the hard template and sucrose as a low cost naturally occurring carbon source. The as-synthesized carbon/silica composites were carbonized at three different temperatures of 700, 800 and 900 °C followed by etching. The synthesized MCSs were characterized by a variety of techniques including: small and wide angle X-ray diffraction, Raman spectroscopy, nitrogen sorption studies, scanning electron microscopy, high resolution transmission electron microscopy and contact angle measurements. The electrochemical behavior of the synthesized material was studied using three techniques, namely, cyclic voltammetry, galvanostatic charge/discharge and potentiostatic electrochemical impedance spectroscopy. As a pristine carbon material, the synthesized electrodes in this study exhibited promising properties in comparison with other mesoporous carbon electrodes reported in the literature including: high specific capacitance (163.88 F g−1) at a 1 mV scan rate, superior electrical conductivity, better hydrophilicity and low charge transfer resistance. The desalination potency including the recyclability of the electrodes was evaluated and our material showed reasonable salt adsorption capacity (9.29 mg g−1), which makes the mesoporous carbon spheres (MCSs) in this work stand out as a potential candidate for CDI based water desalination. [ABSTRACT FROM AUTHOR]

Hydrogen production through electrocatalysis is crucial in renewable energy technologies but significantly impeded by sluggish anodic reactions. Developing bifunctional anode noble-metal-free electrocatalysts towards oxygen evolution reaction (OER) and urea oxidation reaction (UOR) to boost cathodic hydrogen evolution reaction (HER) is promising but challenging to meet different reaction media and multiple applications for simultaneous clean energy production and pollution treatment. Herein, a facile one-pot thermal treatment strategy is presented to anchor NiFe nanoclusters (with a size of about 2 nm) on N-doped carbon as bifunctional electrocatalysts for both OER and UOR. Such an electrocatalyst can deliver a current density of 20 mA cm−2 with a low overpotential of 260 mV and a small Tafel slope of 42 mV dec−1 for OER, superior to the state-of-the-art Ru-based materials. Besides, this electrocatalyst also shows excellent activity for UOR with the need for just 1.37 V (vs. RHE) to attain a current density of 100 mA cm−2. In a two-electrode electrolyzer for both cathodic HER and anodic UOR, only a cell voltage of 1.50 V is required to drive a current density of 10 mA cm−2, which is 140 mV lower than that of overall water splitting electrolysis (1.64 V). The excellent electrooxidative performance can be attributed to the improved conductivity, abundant active sites and fast charge transfer and transport benefiting from the ultrafine structure of NiFe clusters and their synergistic effect with N-doped carbon. [ABSTRACT FROM AUTHOR]

The surface characteristics of electrodes vary depending on the solvent used. Furthermore, electrochemical performance varies depending on the surface morphology of the electrode. In this study, we grew 3D binary NiCu-based composites on Ni foam, via a binder-free hydrothermal method, for use as a cathode in high-performance supercapacitors. We employed different solvents to prepare the electrodes by adjusting the ratio of deionized water (DI water) to methanol. The electrode prepared using DI water as the solvent had the largest surface area with a nanowire structure. This morphology allowed for good electrical performance by greatly improving the electrode and electrolyte contact area and shortening the ion diffusion path. The optimized deposition of NiCu(CO3)(OH)2 nanowires (50 mL of DI water as solvent) showed an excellent maximum specific capacity of 758.9 mA h g−1 at a current density of 3 A g−1, as well as outstanding cycling performance with 87.2% retention after 5000 cycles. In this work, we focused on the large specific surface area and suitable electrochemical properties of NiCu(CO3)(OH)2 electrodes with various solvents. As a result, the asymmetric supercapacitor (ASC) using the NiCu(CO3)(OH)2 electrode prepared with 50 ml of DI water as the solvent as the positive electrode and graphene as the negative electrode, exhibited an energy density of 26.7 W h kg−1 at a power density of 2534 W kg−1, and excellent cycling stability with 91.3% retention after 5000 cycles. The NiCu(CO3)(OH)2//graphene ASC could turn on an LED light and demonstrated better electrical performance than most previously reported nickel- and copper-based carbonate hydroxide ASCs. In addition, in the present scenario where many nanoscale studies are conducted, a method of controlling the nanostructure of a material through facile solvent control will be of great help to many researchers. [ABSTRACT FROM AUTHOR]

Herein, we report a multifunctional device with an integrated energy-desalination-smart electrochromic display in one single cell. Specifically, a novel chemically assisted electrochromic desalination set-up was demonstrated using a Prussian blue cathode and an anode comprising Ag or a redox polymer film in salt water without any external electrical energy usage. [ABSTRACT FROM AUTHOR]

To simplify the preparation process and increase the drug-loading capacity of antitumor nanodrugs, doxorubicin-loaded micelles based on zwitterionic oligopeptides were fabricated through two step reactions in mild conditions. Zwitterionic oligopeptides Glu–Lys–Cys–Glu–Lys (EKCEK) were reacted with methacrylohydrazide (MAH) by click reaction, the product was further conjugated with doxorubicin (Dox) to form amphipathic molecules, and finally the amphipathic molecules self-assembled into doxorubicin-loaded micelles (EKCEK–Dox) in deionized water. TEM and DLS results showed that the EKCEK–Dox micelles were of the regular sphere, with the mean diameter approximately 70 nm. The drug-loading capacity of the prepared micelles was up to 44.6%, and the micelles were very stable in PBS solution. In vitro antitumor experiment showed that the EKCEK–Dox micelles had significant inhibition efficacy on MCF-7 cells, which was much better than the clinical antitumor drug (Doxil®). The IC50 of the EKCEK–Dox micelles (5.6 μg Dox equiv. per mL) was significantly lower than Doxil (8.9 μg Dox equiv. per mL). Therefore, the drug delivery system based on zwitterionic oligopeptides will be a promising strategy for cancer chemotherapy. [ABSTRACT FROM AUTHOR]

Desalination techniques, such as reverse osmosis, distillation, capacitive deionization, and battery desalination, require lots of electrical or thermal energy consumption. Herein, we propose a consumption-free electrochemical desalination method based on a light-driven photocathode with a Pt/CdS/Cu2ZnSnS4(CZTS)/Mo architecture. Modification of a CdS layer on CZTS can improve the desalination performance due to the formation of inner p–n junction between CdS and CZTS which enhances the separation of the photoexcited carriers without recombination. This photocathode-assisted electrodialysis desalination plays the dual functions of both energy conversion and ion removal with the blocking of ion exchange membranes. The [Fe(CN)6]3−/4− redox couples are recirculated between the anode and photo-cathode as the electrolyte while the salt streams are fed into the middle compartment. Under light illumination, this architecture produces photo-generated electrons to the redox couples with the conversion of [Fe(CN)6]3− to [Fe(CN)6]4− at the positive chamber, causing cation capture in the presence of an ion-exchange membrane. At the same time, [Fe(CN)6]4− is oxidized at the negative reservoir. The light-driven electrochemical reaction of electrolyte redox couples can result in a continuous desalination process. This work will be significant for consumption-free photoelectrochemical desalination research. [ABSTRACT FROM AUTHOR]

Designing low-cost and high-performance bifunctional electrocatalysts towards hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is vitally important for water splitting. Herein, we synthesize Co2−xNixO2 (0 < x < 1.0) hexagonal nanosheets with different Co/Ni molar ratios via a facile coprecipitation process followed by calcination under an Ar atmosphere. Changing the Co/Ni molar ratios of the Co2−xNixO2 products is found to have a momentous influence on the microstructures, specific surface areas and electrocatalytic performances. At a Co/Ni molar ratio of 0.6, the Co1.4Ni0.6O2 nanosheet exhibits the largest specific surface area of 60.63 m2 g−1, the best OER with an onset overpotential of 278.5 mV, and HER of 72.8 mV as a bifunctional electrocatalyst. Meanwhile, the minimum Tafel slope is 113.6 mV dec−1 for OER and 77.4 mV dec−1 for HER. The Co1.4Ni0.6O2 nanosheet has excellent OER and HER activity at 0.1 mg cm−2 trace loading. Moreover, we construct an overall water splitting cell using the Co1.4Ni0.6O2 bifunctional electrocatalyst in a two-electrode system to further demonstrate the practical application, which needs a cell voltage of 1.75 V at a current density of 10 mA cm−2 and exhibits great long-term stability. These results provide an efficient strategy for the rational design of Co-based oxides towards bifunctional overall water electrocatalysts. [ABSTRACT FROM AUTHOR]

Herein we report a new technique combining acoustic levitation and infrared thermography to directly monitor droplet surface temperatures. Using it, temperature profiles were recorded during the evaporation of deionized water, methanol, n-propanol, and isopropanol. Results support the viability of this inexpensive and easily-accessed technique for studying chemical and physical changes in droplets. [ABSTRACT FROM AUTHOR]

We report a label-free biosensor for the detection of Escherichia coli O157:H7 ATCC 43895 in potable water using a newly designed DNA sensing probe targeting the z3276 genetic marker. The surface of indium tin oxide (ITO) was functionalized with the novel sensing probe by covalent coupling using APTES as a crosslinker to fabricate the DNA sensor (dubbed ZEC [z_;3276 gene of E_;. c_;oli O157:H7 ATCC 43895]). The electrochemical characterization of the fabricated ZEC sensor was performed using cyclic voltammetry and electrochemical impedance spectroscopy. Atomic force microscopy and scanning electron microscopy revealed significant changes in the surface topographies of the fabricated ZEC sensor chip. Equivalent circuit analyses suggested the capacitive nature of the ZEC sensor chip, which demonstrated a declining trend of the capacitance value from 1.568 μF (Bare ITO) to 1.221 μF (after DNA hybridization). Non-faradaic sensing measurements revealed systematically declining capacitance values upon DNA hybridization, with a 10 min response time at 10 Hz frequency and 10 mV applied potential. The ZEC sensor chip exhibited linearity in the range of 0.5 to 25 pg per 10 mL for E. coli O157:H7, with ubiquitous cross-validation of each DNA concentration using quantitative PCR prior to the analyses of real water samples. The limit of detection (LOD) at 95% confidence estimated by logistic regression was 0.1 pg DNA per 10 mL of E. coli O157:H7 (equivalent to 13.67 CFU per 10 mL) with a p-value of 0.0237. Consequently, the obtained results demonstrate the possible application of the developed ZEC sensor chip for E. coli O157:H7 detection in real water samples. [ABSTRACT FROM AUTHOR]

We present the unprecedented application of a black phosphorus-based nanocomposite as an electrode for aqueous Na-ion batteries under ambient conditions. An impressive specific capacity of up to 200 mA h g−1 was reached after 50 cycles in a NaCl aqueous solution used as a supporting electrolyte. Post-characterization indicated the integrity of the black phosphorus. [ABSTRACT FROM AUTHOR]

The use of an open droplet system for surface acoustic wave (SAW)-based applications has been limited by droplet instability at high input power. This study introduces a dome-shaped chamber-based SAW (DC-SAW) device for the first time, which can be fabricated simply using a single adhesive tape and a drop of ultraviolet-curable material without soft lithography processes. The dome-shaped chamber device with a contact angle of 68° enables the maximizing of the effect of SAW transmitted at a refraction angle of roughly 22°, negating the droplet instability. The DC-SAW device was applied to acoustic mixing to estimate its capability. Acoustic mixing of two different fluids (i.e., deionized water and fluorescent particle suspension) was demonstrated in the dome-shaped chamber device. Moreover, the effect of flow rate and applied voltage on mixing performance was estimated. With the decreasing flow rate and increasing applied voltage, mixing performance was enhanced. At an applied voltage of 20 V, mixing indices were higher than 0.9 at a total flow rate of 300 μl min−1. [ABSTRACT FROM AUTHOR]

Layered double hydroxides (LDHs) have shown great potential to prevent chloride penetration into cementitious materials. This paper intends to investigate the effect of the divalent cation type and divalent to trivalent metal ion ratio of LDHs on their chloride binding capacity. Different types of M2+ (Mg, Ca, Zn)–Al–NO3 LDHs were prepared by a hydrothermal synthesis method. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and thermogravimetry and differential scanning calorimetry (TG-DSC) were adopted to characterize the synthesized LDHs. In addition, the chloride binding capacity of LDHs was measured using the equilibrium isotherm of chloride binding. These results indicated that Zn–Al–NO3 LDH (Z-LDH) exhibited the largest chloride binding capacity because of its greatest basal spacing compared with Mg–Al–NO3 LDH (M-LDH) and Ca–Al–NO3 LDH (C-LDH). The chloride binding capacity of Z-LDH increased with the decrement of the divalent to trivalent metal ion ratio ranging from 2 to 4. Due to the competitive binding of anions, the chloride binding capacity of LDHs in simulated concrete pore (SCP) solution was slightly lower than that in deionized water. However, simulated carbonation of the SCP solution resulted in considerable desorption of chloride. Special attention should be paid to the desorption of chlorides caused by carbonation if LDHs are used in cementitious materials to prevent chloride penetration. [ABSTRACT FROM AUTHOR]

Ciprofloxacin (CFX) is a widely used second-generation fluoroquinolone, broad-spectrum antibiotic. Increasingly, it has been detected in water supplies and has been shown to be harmful to the environment. Antibiotic contamination in the aquatic environment has adverse effects on non-target organisms, including promoting bacterial resistance, inhibiting algae growth, affecting chloroplast replication, transcription and translation, and disrupting the N cycle involved in microorganisms. Here, a novel electrochemical sensor was developed based on simple nitrogen plasma modification; critically, this sensor effectively detected CFX in water. Collectively, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), contact angle (CA) measurements, and electrochemical impedance spectroscopy (EIS) were used to characterize the physical and electrochemical properties of the electrode. The results showed that both the electrochemical activity and the electron transfer of the carbon electrode were significantly enhanced by the nitrogen plasma modification. This was likely due to an increase in nitrogen functional groups (i.e., the nitrogens contained within the pyrrole and graphite groups) and it did not result in damage to the roughness of the electrode's surface. These results also indicated that our sensor selectively detected CFX in the presence of interference antibiotics and/or inorganic ions. Under optimal conditions (pH = 5, plasma power = 140 W, and modification time = 8 min), our sensor showed a broad linear concentration range (2.5 × 10−7–1.0 × 10−4 M) with detection limits as low as 8 nM. The sensor was also successfully applied in the detection of CFX in different types of water sources, namely groundwater and tap water. The recoveries varied from 92.10 to 109.48% with a relative standard deviation (RSD) less than 4.07%. Taken together, these results show a simple and rapid modification method that provides a promising means for rapid, in situ sensor-based monitoring of aquatic environmental pollutants like antibiotics. [ABSTRACT FROM AUTHOR]

A rational design of heterostructures for electrode materials is highly desired for boosting the electrochemical performance, but it is still challenging, especially through a cost-effective method. Herein, novel NiCo2O4 nanosheet-decorated leaf-like Co3O4 nanoarrays have been constructed on a Ni foam using a leaf-like Co-based metal–organic framework (Co-MOF-L) template, which can be simply prepared in an aqueous solution at room temperature. Combining the merits of MOF derivatives and the free-standing core–shell heterostructure, the leaf-like Co3O4@NiCo2O4 nanoarray electrode displayed a high specific capacity of 544.2 C g−1 at 1 A g−1, which is almost 9.3 times that of Co3O4 (58.3 C g−1) and 6 times that of NiCo2O4 (92.1 C g−1). It also displayed a good rate capacity (65.5% at 10 A g−1) and superior long-term stability (93.0% capacity retention over 5000 cycles at 10 A g−1). Moreover, a hybrid supercapacitor (HSC) assembled from the battery-type Co3O4@NiCo2O4 electrode and a capacitive activated carbon (AC) electrode delivered a high energy density of 36 W h kg−1 at a high power density of 852 W kg−1 with good cycling stability, demonstrating a capacity retention of 89.5% after 10 000 cycles at 10 A g−1. Furthermore, two connected HSCs could light up a red light-emitting diode (LED). Therefore, the as-fabricated leaf-like Co3O4@NiCo2O4 nanoarrays hold great promise as binder-free electrodes in electrochemical energy storage devices. [ABSTRACT FROM AUTHOR]

Herein, a nanoflake array composed of CoFe2O4 and CoFe2S4 was in situ assembled on nickel foam (CFS-10/NF) via a simple surface modification by sulfidation; the composition and structure of this array were confirmed by various techniques such as transmission electron microscopy and X-ray diffraction. When applied as an additive-free electrode material, the 3D CFS-10/NF sample exhibited an outstanding capacitance property (4.6 F cm−2 at 1 mA cm−2), good rate capability and stable cycling performance. The asymmetric supercapacitor device with CFS-10/NF as an anode and activated carbon as a cathode showed superior performance with the high areal capacitance of 190.5 mF cm−2 and the energy density of 19.8 W h kg−1. Moreover, the sample exhibited good cycling stability with 100% capacitance retention after 3000 cycles. Due to the rich redox reaction and high electrical conductivity boosted by the well-designed composition as well as large specific surface area and a short ion transportation path attributed to its nanoflake structure, the composite material demonstrates a promising prospect in energy storage applications. [ABSTRACT FROM AUTHOR]

Metal/covalent–organic framework (MOF/COF) membranes have attracted increasing research interest and have been considered as state-of-the-art platforms applied in various environment- and energy-related separation/transportation processes. To break the trade-off between permeability and selectivity to achieve ultimate separation, recent studies have been oriented towards how to design and exploit ultrathin MOF/COF membranes (i.e. sub-1 μm-thick). Given great advances made in the past five years, it is valuable to timely and systematically summarize the recent development and shed light on the future trend in this multidisciplinary field. In this review, we first present the advanced strategies in fabricating ultrathin defect-free MOF/COF membranes such as in situ growth, contra-diffusion method, layer-by-layer (LBL) assembly, metal-based precursor as the pre-functionalized layer, interface-assisted strategy, and laminated assembly of MOF/COF nanosheets. Then, the recent progress in some emerging applications of ultrathin MOF/COF membranes beyond gas separation is highlighted, including water treatment and seawater desalination, organic solvent nanofiltration, and energy-related separation/transportation (i.e. lithium ion separation and proton conductivity). Finally, some unsolved scientific and technical challenges associated with future perspectives in this field are discussed, inspiring the development of next-generation separation membranes. [ABSTRACT FROM AUTHOR]

Osmosis is a universal phenomenon occurring in a broad variety of processes and fields. It is the archetype of entropic forces, both trivial in its fundamental expression – the van 't Hoff perfect gas law – and highly subtle in its physical roots. While osmosis is intimately linked with transport across membranes, it also manifests itself as an interfacial transport phenomenon: the so-called diffusio-osmosis and -phoresis, whose consequences are presently actively explored for example for the manipulation of colloidal suspensions or the development of active colloidal swimmers. Here we give a global and unifying view of the phenomenon of osmosis and its consequences with a multi-disciplinary perspective. Pushing the fundamental understanding of osmosis allows one to propose new perspectives for different fields and we highlight a number of examples along these lines, for example introducing the concepts of osmotic diodes, active separation and far from equilibrium osmosis, raising in turn fundamental questions in the thermodynamics of separation. The applications of osmosis are also obviously considerable and span very diverse fields. Here we discuss a selection of phenomena and applications where osmosis shows great promises: osmotic phenomena in membrane science (with recent developments in separation, desalination, reverse osmosis for water purification thanks in particular to the emergence of new nanomaterials); applications in biology and health (in particular discussing the kidney filtration process); osmosis and energy harvesting (in particular, osmotic power and blue energy as well as capacitive mixing); applications in detergency and cleaning, as well as for oil recovery in porous media. [ABSTRACT FROM AUTHOR]