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Nanoscale zero-valent iron (nZVI or Fe

Green synthesized silver nanoparticles (AgNPs) have gained considerable interest because of their potential applicability in numerous fields, including biomedicine. This study proposed a green, rapid, and effective synthesis of AgNPs using Punica granatum extracts and sunlight for effective breast cancer treatment. Phytochemical analysis of Punica granatum extracts confirmed the existence of phyto-compounds, which are responsible for coating and stabilizing the AgNPs. The optimization study suggested that rapid synthesis of AgNPs can be accomplished using sunlight. Fourier transform infrared spectroscopy analysis confirmed bio-compounds deposition in P. granatum extracts on the AgNPs. The results showed that the biosynthesized AgNPs were highly stable at −27 mV and spherical in sizes from 13 to 37 nm. The anticancer activity evaluation results demonstrated that the AgNPs using P. granatum under sunlight possess significant antiproliferative and apoptosis-inducing activities in breast cancer cells. The apoptotic properties of AgNPs using P. granatum leaves (AgNPs-PL) were assessed by morphological observations, DAPI staining, DNA fragmentation assay, and flow cytometry. The results show the potential therapeutic value of the biosynthesized AgNPs for further development as anticancer drugs.

Silver nanoparticles (AgNPs) have been considered promising candidates for medical practices in various fields. This study proposed an efficient, economical, uncomplicated, and reliable method to synthesize AgNPs utilizing leaf and fruit extracts of Juniperus procera (J. procera) as capping, reducing, and stabilizing agents. The study includes optimizing the green synthesis conditions to produce stable AgNPs with high yields, acceptable particle size, and shape, hence, AgNPs may be used for different medical purposes through the improvement of their properties. Several spectroscopic and other analyses performed characterization of the fabricated AgNPs, and the results show stable and spherical AgNPs between 14 and 18 nm in size. The study also evaluated the anticancer activities of the biosynthesized AgNPs using J. procera fruit and leaf extracts against in vitro lung cancer A549 and H1975 cells. The results demonstrate the high toxicity of the biosynthesized AgNPs against in vitro lung cancer cells, supporting therapeutic and biomedical applications of AgNPs.

Recent progress in environmental remediation, colloidal behavior and biological effects of MXene was summarized.

The exploitation of multifunctional nanocomposites is highly desired in environmental monitoring, biosensors, and medical diagnosis. In this paper, a simple approach has been proposed to fabricate MoS2 decorated N-doped carbon nanotubes (NCNTs@MoS2) hybrid composites as efficient peroxidase-like mimics. The combination of the MoS2 and N-doped carbon nanotubes (NCNTs) brings about an enhanced synergistic effect, leading to remarkably decent intrinsic peroxidase-mimic activities than that of the single components. Due to the high catalytic efficiency of the resultant NCNTs@MoS2 hybrid nanotubes as peroxidase-like mimics, a convenient colorimetric approach for the sensitive determination of H2O2 and ascorbic acid have been developed with a detection limit of about 0.14 μmol/L and 0.12 μmol/L, respectively. The work offers a new strategy for the fabrication of peroxidase-like nanomaterials with excellent catalytic activity, which indicates great promising applications in sensitive detections in real samples.

With the rapid development of industrial, large amounts of different inorganic and organic pollutants are released into the natural environments. The efficient elimination of environmental pollutants, i.e., photocatalytic degradation of persistent organic pollutants into nontoxic organic/inorganic chemicals, in-situ solidification or sorption-reduction of heavy metal ions, is crucial to protect the environment. Nanomaterials with large surface area, active sites and abundant functional groups could form strong surface complexes with different kinds of pollutants and thereby could efficiently eliminate the pollutants from the aqueous solutions. In this review, we mainly focused on the recent works about the synthesis of nanomaterials and their applications in the efficient elimination of different organic and inorganic pollutants from wastewater and discussed the interaction mechanism from batch experimental results, the advanced spectroscopy techniques and theoretical calculations. The adsorption and the photocatalytic reduction of organic pollutants and the sorption/reduction of heavy metal ions are generally considered as the main methods to decrease the concentration of pollutants in the natural environment. This review highlights a new way for the real applications of novel nanomaterials in environmental pollution management, especially for the undergraduate students to understand the recent works in the elimination of different kinds of inorganic and organic chemicals in the natural environmental pollution management.

In this study, nanoscale zero-valent iron (nZVI) particles were synthesized on fullerene, carbon nanotubes, and graphene to use with S. putrefaciens for U(VI) reduction under light conditions. Of t...

A protocol of SO2F2-mediated installation of sulfonyl fluoride onto primary amides has been developed providing a new portal to sulfur(VI) fluoride exchange (SuFEx) click chemistry. The generated molecules contain pharmaceutically important amide and -SO2F moieties for application in the discovery of new therapeutics.

A simple, practical and gram-scale process for direct transformation of primary alcohols or silyl ethers to ammonium salts was developed. This method has the feathers of easy work-up (a simple filtration), mild condition, high yield, great practicality and robustness. And the application of the ammonium salts in Suzuki coupling reaction was also accomplished.

A facile method for the construction of esters through dehydrative coupling of carboxylic acids with alcohols is developed. The reactions are mediated by sulfuryl fluoride (SO2F2) at room temperature and proceed with high efficiency. The method has several advantages including broad substrate scope, mild conditions, excellent functional group compatibility and affords high yields, even on gram scale.

At present more than 250 FDA approved chlorine containing drugs were available in the market and many pharmaceutically important drug candidates in pre-clinical trials. Thus, it is quite obvious to expect that in coming decades there will be an even greater number of new chlorine-containing pharmaceuticals in market. Chlorinated compounds represent the family of compounds promising for use in medicinal chemistry. This review describes the recent advances in the synthesis of chlorine containing heterocyclic compounds as diverse biological agents and drugs in the pharmaceutical industries for the inspiration of the discovery and development of more potent and effective chlorinated drugs against numerous death-causing diseases., Graphical abstract Image 1, Highlights • The applications of chlorine in medicinal chemistry is one of the fastest growing hot research areas in the chemistry community. • More than 250 FDA approved chloro-containing drugs are in the market. • This review summarizes nearly 130 FDA approved drugs against diverse biological agents. • Discussions of the SAR of potent drugs were included.

An urchin-like nano-composite of SnO2/NaNbO3 was fabricated by the hydrothermal method and the influence of the Sn/Nb ratio in the samples on their humidity-sensing properties was investigated. The phases and morphologies of these composites and their elemental distributions were analyzed by X-ray diffraction scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The sensor based on the optimum Sn/Nb ratio of 1:0.4 exhibited remarkable humidity-sensing properties, including a good response (S = 4823.8) that was 8.72 times higher than that of the pure SnO2 sensor (S = 553.01). The composites showed rapid response and recovery times (3/9 s), as well as good stability, linearity, and excellent selectivity. The fabrication and humidity-sensing mechanisms were systematically analyzed using analog computations and Nyquist diagrams, respectively. Compared with pure NaNbO3 and SnO2 sensors, our easily prepared SnO2/NaNbO3 sensor demonstrates good sensing properties and holds great promise for use in humidity-sensing applications.

In recent years, the fabrication of noble metal functionalized magnetic carbon nanotubes for a variety of novel biosensors has aroused considerable interest owing to their synergistic improved sensitivity. In the paper, the Fe3O4 and Cu nanoparticles (NPs) were integrated into the NCNTs to obtain N-doped carbon@Fe3O4-Cu nanotubes (NCNTs@Fe3O4@Cu) through a one-pot high temperature decomposition procedure. Then, Au NPs were assembled on the magnetic NCNTs to obtain NCNTs@Fe3O4@Au composite by galvanic replacement with Cu NPs. The resultant composite had provided a friendly platform for enzyme immobilization to develop highly sensitive biosensors. After the cytochrome c(cyt c) was accumulated by NCNTs@Fe3O4@Au composite, the cyt c/NCNTs@Fe3O4@Au gathered to the surface of electrode with an external magnet. Thus, the sensitivity of designed biosensor could be further improved, and most of electrochemical interferences could be excluded. Benefiting from the unique hybrid structure of the composite, the direct electron transfer of cyt c was highly facilitated and the constructed biosensors exhibited good performance for the detection of H2O2 with an extraordinary low detection limit of 0.3 μM, which revealed potential application for fabricating novel electrochemical biosensors.

One-dimensional (1D) carbon fabric (CF) anchored with high-density of nickel nanoparticles (NPs) has been successfully fabricated by combining an extended Stober approach with a carbonization process. Hybrid CF@PDA-Ni2+ was first synthesized by the coating of the polydopamine-Ni2+ (PDA-Ni2+) layer on carbon fabric in a Stober condition. After carbonizing in an inert atmosphere, the CF@C-Ni hybrid in which plenty of Ni NPs embedded in PDA-derived carbon shell on carbon fabric was obtained. Thus, the prepared CF@C-Ni composites can be employed as the catalyst for the reduction of 4-nitrophenol (4-NP). Additionally, the size and density of Ni NPs could be finely controlled via changing the carbonization temperature. Moreover, the CF@C-Ni composites can be easily collected and recycled with little loss because of their unique structures, which is important for practical applications.

A well-organized quasi-solid-state electrolyte is formed by binary mixtures of bisamide and valine as co-gelator via intermolecular hydrogen bonds. It is interesting that the ratio of the two components of quasi-solid-state electrolyte can be tuned to shift the position of TiO2 conduction band edge, which can obviously enhance the driving force of electron injection process. Consequently, compared with the liquid electrolyte based dye-sensitized solar cell DSSC, the short-circuit current density (Jsc) of solar cellassembled by this quasi-solid-state electrolyte is increased about 12%. Moreover, the intensity-modulated photocurrent spectroscopy/intensity-modulated photovoltage spectroscopy (IMPS/IMVS) and electrochemical impedance spectroscopy (EIS) are carried out to investigate the influences of gelation on the kinetic processes of electron transport and recombination in DSSC. It is found that with the increasing of valine, the 3D network of quasi-solid-state electrolyte becomes looser and the electron transportation process is accelerated, meanwhile, the electron recombination lifetime is prolonged. As result, the quasi-solid-state solar cells (QS-DSSCs) employed with the bi-component quasi-solid-state electrolytes obtained a higher efficiency of 6.1% at AM 1.5 (100 mW cm2), but the efficiency of QS-DSSC based on the unitary component quasi-solid-state electrolyte formed by bisamide is only 5.3%. More importantly, these QS-DSSCs exhibit more excellent photo-thermal stability than the liquid electrolyte based DSSC.

Magnetic carbon materials promise distinct advantages in the decontamination of heavy metal ions. In this work, a novel interconnected hierarchical nickel-carbon (Ni@IHC) hybrid was synthesized by combining the solvothermal method with a one-step pyrolysis under argon atmosphere. Benefitting from 3D flower-like morphology, interconnected porous nanosheets, large surface area, and abundant Ni nanoparticles, Ni@IHC hybrids can remove Cr(VI) within 25 min by using formic acid (FA) as a reductant at 25 ℃. Furthermore, the experimental parameters that can affect the material catalytic performance such as initial Cr(VI) concentration, catalyst dosage, FA concentration, and temperature were also investigated in detail. It was found that highly dispersed Ni nanoparticles contributed significantly to the reduction process. More importantly, the embedded Ni nanoparticles favor fast separation by a magnet and were helpful for the recycles use. This Ni@IHC hybrid was obtained by a facile and easy scale-up method, resulting in the fast transformation of Cr(VI) into Cr(III).

This article is concerned with the H

This article is concerned with the H∞ state estimation problem for a class of bidirectional associative memory (BAM) neural networks with binary mode switching, where the distributed delays are included in the leakage terms. A couple of stochastic variables taking values of 1 or 0 are introduced to characterize the switching behavior between the redundant models of the BAM neural network, and a general type of neuron activation function (i.e., the sector-bounded nonlinearity) is considered. In order to prevent the data transmissions from collisions, a periodic scheduling protocol (i.e., round-robin protocol) is adopted to orchestrate the transmission order of sensors. The purpose of this work is to develop a full-order estimator such that the error dynamics of the state estimation is exponentially mean-square stable and the H∞ performance requirement of the output estimation error is also achieved. Sufficient conditions are established to ensure the existence of the required estimator by constructing a mode-dependent Lyapunov-Krasovskii functional. Then, the desired estimator parameters are obtained by solving a set of matrix inequalities. Finally, a numerical example is provided to show the effectiveness of the proposed estimator design method.

Herein, we propose a strategy of rapid assembly of Ag3PO4 nanoparticles (NPs) within three dimensional (3D) keratin–inorganic hybrid nanoflowers (keratin-NF@Ag3PO4) with a facile in situ ion sedimentation approach. The 3D porous networks greatly prevent polycondensation of Ag3PO4 NPs because of the porous and interconnected microstructures, which enhanced the catalytic activity in the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) into a blue colored product (oxTMB) in the presence of H2O2. However, the addition of uric acid (UA) could lead to the reduction of oxTMB, resulting in fast fading of the blue color. Inspired by this finding, a simple and sensitive colorimetric assay for uric acid (UA) has been developed with a detection limit (LOD) of 0.94 μM. Furthermore, this strategy has been successfully applied to the detection of UA in practical samples.

A cascade dehydrogenative Morita–Baylis–Hillman reaction of the C(sp3)–H of primary alcohols with the C(sp2)–H of electron-deficient olefins for forming allylic alcohols mediated by SO2F2 was developed. This method provides a mild process for the preparation of allylic alcohol moieties without the requirement of transition metals.

The performance in adsorption and catalysis efficiency are closely dependent on the morphology and structure of the catalysts and adsorbents. Herein, three dimensional (3D) macro-/mesoporous TiO2@C–Ni composites were successfully fabricated using polymethylmethacrylate (PMMA) as a sacrificial template. Notably, the inorganic interlayer of TiO2 or SiO2 played an essential role in generating such 3D macro-/mesoporous TiO2(SiO2)@C–Ni composites. In the absence of TiO2 or SiO2, aggregated C–Ni composites were obtained instead. Owing to the well-defined 3D macro-/mesoporous structures as well as high coverage of Ni nanoparticles (NPs), the TiO2@C–Ni composites obtained at 500 °C in a N2 atmosphere exhibited excellent performance in catalysis and protein adsorption. Moreover, the morphology of the 3D TiO2@C–Ni composites was greatly influenced by changing other different carbonization temperatures (700, 900 °C). Interestingly, when PMMA@TiO2@PDA–Ni2+ was annealed at 900 °C, all of the generated carbon nanotubes as well as the TiO2 interlayer were weaved together into a continuous 3D network, which will endow this kind of material with enhanced properties and excellent performance in energy storage fields.

Highly emissive three-coordinate copper(I) complexes have received much attention. Here, a new synthetic strategy for the preparation of a bulky terphenyl bidentate phosphine ligand mpdp is presented. A series of mononuclear three-coordinate Cu(I) halide complexes [CuX(mpdp)] (mpdp = 4,4′,4′′,5,5′,5′′–hexamethyl-(1,1′:2′,1′′-terphenyl)-2,2′′-bis(diphenylphosphine), X = I (1), Br (2) and Cl (3)), were synthesized. This method provides a three-coordinate linkage between the bulky bidentate phosphine ligand and CuX. These complexes exhibit green to yellow green emission in the solid state at room temperature and have peak emission wavelengths at 493–533 nm with microsecond lifetimes (τ = 7.2–415.9 μs). Small S1–T1 energy gaps in the solid state indicate that the emission occurs from a thermally activated excited singlet state at ambient temperature. The emission of complexes 1–3 mainly originates from MLCT and XLCT transitions. The solution-processed devices of complex 1 exhibit yellow emission with a CIE (x, y) of (0.44, 0.47).

The surface area and structure of adsorbents are crucially important to its adsorption capacity. Herein, we focused on the correlation between the structures of 2D/3D materials and its adsorption properties by taking three kinds of cobalt–aluminum layered double hydroxide (CoAl-LDH) as adsorbents, including a 3D hierarchical flower-like hollow/solid sphere (FH/FS-CoAl) and 2D plate (P-CoAl). As expected, FH-CoAl showed the highest adsorption capacity (∼2189.23 mg/g) for methyl orange (MO), benefiting from the highly accessible surface areas and more active sites of unique hollow structural characteristics inherited from the hierarchical flower-like hollow structures. Interestingly, compared with FS/FH-CoAl, P-CoAl exhibited the highest adsorption capacity enhancement times after being normalized with surface area, but displayed an inferior maximum adsorption capacity. The reasons could be mainly ascribed to (1) P-CoAl with 2D plate structures possessed more fully exposed active sites than FH-CoAl and (2) ...

A novel xanthate-modified chitosan/poly(N-isopropylacrylamide) (X-CS/NIPAAm) composite hydrogel was fabricated by a facile two-step method for the selective adsorption of Cu(II), Pb(II) and Ni(II) metal ions from aqueous solutions. The equilibrium adsorption data fitted well to the Langmuir model and the adsorption kinetic data followed the pseudo-second-order model. The maximum equilibrium adsorption capacities of composite hydrogel to Cu(II), Pb(II) and Ni(II) at 293 K were about 115.1, 172.0 and 66.9 mg g−1, respectively. The thermodynamics parameters showed that the adsorption processes to Cu(II), Pb(II) and Ni(II) were spontaneous and exothermic. The interactions between metal ions for multi-components systems were evaluated by the values of Qb/Qs and Qt/Qs. The adsorption mechanism was analyzed by XPS spectra and the Hard–Soft, Acids–Bases (HSAB) theory. The X-CS/NIPAAm composite hydrogel could be regenerated and repeatedly utilized at least five cycles without obvious adsorption capacity loss.

A new environmentally friendly and low–cost adsorbent was produced from the camphor tree leaves (BC@CTL) and used to remove U(VI) from waste water via batch capture experiments under varying pH, time, and U(VI) concentration. The resultant biochar was characterized by SEM, BET, zeta-potentials, and FTIR spectroscopy. The capture process was strongly dependent on pH and independent of ionic strength. The capture experimental results indicated that U(VI) was quickly captured to BC@CTL with a maximum capture capacity of 0.41 mmol U(VI) g−1 obtained by Langmuir model fitting. The results of EXAFS analysis revealed that the interaction mechanism of U(VI) on the BC@CTL was primarily controlled by inner-sphere surface complexation. The investigation was meaningful for the “treating wastewater with wastes” strategy implementation, especially biochar can be regarded as a promising candidate for the pre-concentration and immobilization of radionuclides from aqueous solutions in environmental remediation.

The NiAl layered double hydroxides (NiAl-LDHs) as well as NiAl layered double oxides (NiAl-LDOT, T: 300, 400, 500, 600 °C) were successfully synthesized by hydrothermal process and calcination treatment, and served as adsorbents for the efficient uptake of arsenate (As(V)) from aqueous solutions. Batch experiments were carried out at various solution pH, original As(V) concentration, contact time and calcination temperature. It was found that As(V) adsorption capacity on these composites can be changed by controlling the calcination temperature, and followed the order NiAl-LDO500 (198.1 mg/g) > NiAl-LDO400 (180.9 mg/g) > NiAl-LDO300 (160.2 mg/g) > NiAl-LDO600 (121.4 mg/g) > NiAl-LDH (60.7 mg/g), which could be ascribed to abundant surface adsorption sites and a “memory effect” provided by “Ni-O or Al-O” bonds. The thermodynamic experiments revealed that the elimination of As(V) was spontaneous and endothermic. In addition, multiple characterizations and batch experiments have been carried out to prove the surface adsorption and intercalation by rebuilding of primary layered structure contributed to As(V) adsorption. This discovery can provide a new insight into the elimination of As(V) from wastewater for environmental remediation.

The discharge of microplastics into aquatic environment poses the potential threat to the hydrocoles and human health. The fate and transport of microplastics in aqueous solutions are significantly influenced by water chemistry. In this study, the effect of water chemistry (i.e., pH, foreign salts and humic acid) on the surface charge and aggregation of polystyrene microsphere in aqueous solutions was conducted by batch, zeta potentials, hydrodynamic diameters, FT-IR and XPS analysis. Compared to Na+ and K+, the lower negative zeta potentials and larger hydrodynamic diameters of polystyrene microspheres after introduction of Mg2+ were observed within a wide range of pH (2.0-11.0) and ionic strength (IS, 0.01-500mmol/L). No effect of Cl-, HCO3- and SO42- on the zeta potentials and hydrodynamic diameters of polystyrene microspheres was observed at low IS concentrations ( 10mmol/L). The zeta potentials of polystyrene microspheres after HA addition were decreased at pH2.0-11.0, whereas the lower hydrodynamic diameters were observed at pH

In this paper, multifunctional nanotubes were prepared by directly combing iron oxide (Fe3O4) nanoparticle(NPs) decorated carbon nanotubes (CNTs), and palladium (Pd) NPs together with polypyrrole (PPy) in a facile way. Firstly, magnetic CNT composite (CNTs/Fe3O4) was synthesized by the high temperature decomposition process, then PPy could be easily immobilized on the magnetic CNTs. Furthermore, Pd NPs were accumulated on the surface of CNTs/Fe3O4@PPy to obtain one dimensional CNTs/Fe3O4@PPy/Pd composite. The composite extraordinary amplified the electrochemical response, providing a highly sensitive electrochemical platform for triclosan detection. This electrochemical sensors had the advantage of fast response, cheap instrument, low cost, simple operation, high sensitivity and real-time detection in situ condition. Moreover, the sensor exhibited a wide linear response range for triclosan (2.247 × 10−9 M to 2.752 × 10−7 M) with a detection limit of 1.417 × 10−9 M, respectively. In addition, the electrochemical sensor reported herein was applied for the detection of triclosan in real samples, revealing promising applications in developing the sensor for environmental inspection and monitoring.

The coadsorption of uranium and europium on magnetic attapulgite (M-ATT) was explored through batch experiments and spectroscopic tests. The adsorption processes of U(VI) and Eu(III) onto M-ATT were highly affected by the solution pH but not by the ionic strength, indicating that the adsorption of the two metals was predominated through inner-sphere surface complexation. Adsorption isotherms demonstrated that the maximum adsorption capacities of U(VI) on M-ATT in the single-solute system (e.g., 60.48 mg g–1 at pH 6.0) were lower than that in the binary-solute system (e.g., 63.03 mg g–1 at pH 6.0), and the same trend was noticed for Eu(III) adsorption due to their synergistic effect. The existence of U(VI) and U(IV) species evidenced the partial reduction of adsorbed U(VI) to U(IV) by M-ATT based on XPS tests. Hence, the enhanced adsorption of U(VI) in the existence of Eu(III) is ascribed to the primary coadsorption and then the redox of adsorbed U(VI) to U(IV) by M-ATT, as well as the formation of new sor...

Surface interactions between the adsorbents and heavy metal ions play an important role in the adsorption process, and appropriately decorating the material’s surface can significantly improve the removal capacity of the adsorbents. So, the objective of this study is to modify biochar by coating with molybdenum disulfide (MoS2) for enhancing the adsorption of Pb2+. The biochar pyrolyzed at 600 °C was chosen as the base to combine the flowerlike MoS2 (MoS2@biochar) by solvothermal reaction, in which the abundant S-containing functional groups may promote the elimination of Pb2+. The prepared MoS2@biochar exhibits excellent adsorption capacity (189 mg/g) to Pb2+ in water solution. The adsorption of Pb2+ maintains a high level under the circumstance of coexisting ions (Mg2+, Ca2+, Co2+, and Cd2+), suggesting the high selectivity for Pb2+. The adsorption mechanism of Pb2+ on MoS2@biochar is mainly ascribed to the inner-sphere surface complexation, in particular, metal–sulfur chemical complexation. The easily ...

Magnetic carbon nanotubes composite (MWCNTs-Fe3O4) was successfully prepared and characterized using different techniques. MWCNTs-Fe3O4 displays entangled network of oxidized MWCNTs attached with Fe3O4 clusters with specific surface area of 92 m2 g−1. The adsorption performance of as prepared composite was investigated for Hg(II) removal. Several experimental factors affecting Hg(II) adsorption process by MWCNTs-Fe3O4 were studied including, adsorbent dosage, contact time, pH and metal ion concentration. A high adsorption capacity of 238.78 mg g−1 was obtained according to Langmuir model. In addition, pseudo-second-order and the Langmuir isotherm model were used to fit the adsorption kinetic and equilibrium data, respectively. The results recommend the successful application of MWCNTs-Fe3O4 for Hg(II) removal via batch adsorption technique.