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A cellulose aerogel with very low overall density is fabricated by freeze‐drying aqueous cellulose solution. A hydrophobic/oleophilic cellulose aerogel is further fabricated by coating the cellulose aerogel with hexyltrimethoxysilane‐modified SiO2 nanoparticles. The features of the developed hydrophobic/oleophilic cellulose aerogel are characterized with density and porosity measurement, infrared spectroscopy, X‐ray photoelectron spectroscopy, scanning electron microscopy, and contact angle measurement. Finally, the oil absorption performance of the developed hydrophobic/oleophilic cellulose aerogel is investigated. The results show that SiO2 nanoparticles have been successfully loaded on the surface of the aerogel backbone after fulfillment of fabrication, and the surface of the aerogel turns to be hydrophobic/oleophilic (water contact angle 131° and oil contact angle 0°). The oil absorption experiment results show that the absorption capacity for organic solvents is from 10 to 21 times the initial aerogel weight, depending on the density of the absorbed organic solvents. In addition, the aerogel still maintains good stability in high temperature, strong acid or strong base conditions. Furthermore, the aerogel also shows good performance in separating oil from oil–water mixtures. This hydrophobic/oleophilic cellulose aerogel can be a promising choice for remedying water pollution caused by oil contamination. [ABSTRACT FROM AUTHOR]

Cell-imprinted polymers (CIPs) for yeasts were fabricated via metal-free visible-light-induced atom transfer radical polymerization (MVL ATRP) on the surface of a glassy carbon electrode (GCE) which had been modified with gold nanoparticles (AuNPs)/MXene (Ti3C2Tx) composites. Here, the AuNPs/Ti3C2Tx composites form a macroporous structure, which could improve the electron transfer rate of the materials and facilitate the leaving or rebinding of cells. Methacrylic acid (MAA) and N,N′-methylene bis-acrylamide (MBA) were selected as the functional monomer and cross-linker of CIPs, because they could form efficient hydrogen bonding with mannan from yeast cell walls. The obtained electrode (CIPs/AuNPs/Ti3C2Tx/GCE) was characterized by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Further experiments indicated that the CIPs/AuNPs/Ti3C2Tx/GCE electrode could be utilized as an electrochemical biosensor to determine yeast cells by differential pulse voltammetry (DPV). The linear response range was 1.0 × 102 to 1.0 × 109 cells per mL and the detection limit was 20 cells per mL (S/N = 3). The CIPs/AuNPs/Ti3C2Tx/GCE electrode also showed good selectivity, repeatability, reproducibility, and regeneration. Finally, the proposed sensor was used to detect yeast cells in commercial samples of Saccharomyces boulardii sachets by a standard addition method. The obtained recovery was from 96.9 to 104.8% showing its potential applications in clinical and diagnostic research. [ABSTRACT FROM AUTHOR]

A novel composite adsorbent was prepared by polydopamine (PDA) coating, amination, and carboxylation modification using basalt fiber (BF) as the carrier material for the removal of Cu2+ from water. The resulting adsorbent, BF/PDA-iminodiacetic acid (IDA), was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and thermogravimetric analysis. The effects of pH, ionic strength, temperature, and duration on the adsorption properties of BF/PDA-IDA were investigated by batch experiments. The maximum uptake capacity for Cu2+ was 22.96 mg/g at 303 K. The adsorption process conformed to pseudo-second-order kinetics and the equilibrium can be reached within two hours. The Langmuir isotherm equation fitted well to the adsorption isotherm experimental data. Thermodynamic analysis showed that the adsorption process was spontaneous and exothermal. Furthermore, BF/PDA-IDA can be easily recovered by 0.1 mol/L Na2EDTA and about 90% adsorption capacity remained after four successive regeneration cycles. The adsorption mechanism could be a combination of chelation and electrostatic interactions. This study demonstrated that the adsorbent prepared from BF skeleton has great potential to remove Cu2+ from water. BF/PDA-IDA was prepared by grafting amine and carboxyl groups onto basalt fiber. The adsorption performance of BF/PDA-IDA for Cu2+ was investigated. The desorption rate of BF/PDA-IDA reached more than 99%. The adsorption mechanism of Cu2+ is the result of coordination and electrostatic interactions. [ABSTRACT FROM AUTHOR]

Hemoglobin (Hb) imprinted poly (ionic liquid)s (HIPILs) were fabricated on the surface of Pt wire modified with nano-gold (nAu) via simplified electrochemically mediated atom transfer radical polymerization (seATRP) in only 5 μL volumes. The micro upgrade seATRP was mainly carried out by two platinum wires electrode. The one platinum wire was bare and applied as the counter electrode, the other one was modified segmentally, which made it could be used both as a catalytic electrode of seATRP and the substrate of HIPILs. The HIPILs were prepared by using Hb as the template, 1-vinyl-3-propyl-imidazole sulfonate (VPIS) ionic liquids and N, N′-methylene bis-acrylamide (MBA) as the functional monomer and cross-linking agent of HIPILs, respectively. When a constant current was applied to the catalytic electrode, Fe (III) in Hb would be reduced to Fe (II), seATRP of VPIS would be triggered on the surface of Pt/nAu electrode. After Hb was removed, the HIPILs modified electrode (Pt/nAu/HIPILs) was obtained. The Pt/nAu/HIPILs electrode was characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). Further experiments indicated that the Pt/nAu/HIPILs electrode could be utilized as electrochemical sensor to determine Hb by differential pulse voltammetry (DPV). The linear response range was 1.0 × 10–12 ~ 1.0 × 10–1 mg/mL and the detection limit was 3.29 × 10–13 mg/mL (S/N = 3). Compared with other Hb sensors based on imprinting polymers, the broader linear range and lower detection limit suggested the promising prospect of the biosensor. [ABSTRACT FROM AUTHOR]

A new type of photocatalysts, nanocrystalline titanium dioxide (TiO2) doped with Co and I, were synthesized and modified via the sol-gel method to enhance the utilization of visible light. Herein, mono- and co-doped TiO2 (i.e. Co-TiO2, I-TiO2, Co-I-TiO2) were employed as the photocatalysts to investigate the photocatalytic performance on gaseous benzene removal. The prepared photocatalysts were characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET)-specific surface areas, Raman spectroscopy, UV-visible diffuse reflectance spectroscopy (UV-vis-DRS), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL), and electrochemical impedance spectroscopy (EIS). Results indicated that both particle sizes and band gaps of TiO2 were significantly reduced by doping with Co/I. Also, the lattice defects and the specific surface areas of TiO2 were substantially augmented by adding Co/I because of the increase of oxygen vacancies, especially for Co-I-TiO2. Meanwhile, Co and I were distributed on the titanium base with the existence of multivalent states. The benzene treatment capacity of Co-I-TiO2, Co-TiO2, I-TiO2 and Pure TiO2 is 441.46, 424.36, 388.06, and 51.25 μgC6H6/(g·h), respectively. To sum up, photocatalytic degradation of gaseous benzene could be improved by doping with Co/I because of the extension of catalyst lifetime and light response range covering visible light. [ABSTRACT FROM AUTHOR]

Generally, the pH of fluorinated groundwater or many industrial wastewater is neutral, while the majority of metal-modified adsorbents can work efficiently only under acidic conditions. In this study, we synthesized a novel hybrid adsorbent, Mg–Zr-D213, by loading nano-Mg/Zr binary metal (hydrogen) oxides in a strong-base anion exchanger, D213, to enhance the adsorption of fluoride from neutral water. Mg–Zr-D213 exhibited a better fluoride-removal capacity in neutral water than monometallic modified resins. Under the interference of competing anions and coexisting organic acids, Mg–Zr-D213 exhibited superior selectivity. The Langmuir model indicated that the fitted maximum sorption capacity of Mg–Zr-D213 was 41.38 mg/g. The results of column experiments showed that the effective treatment volume of Mg–Zr-D213 was 8–16-times higher than that of D213 for both synthetic groundwater and actual industrial wastewater, and that NaOH–NaCl eluent could effectively recover more than 95% of fluoride. Adsorption experiments with Mg/Zr metal (hydrogen) oxide particles and D213 separately demonstrated a synergistic effect between –N+(CH 3) 3 and Mg/Zr metal (hydrogen) oxide particles. The ligand exchange or metal-ligand interaction of Mg/Zr metal (hydrogen) oxide particles on fluoride was further demonstrated via X-ray photoelectron spectroscopy. Overall, Mg–Zr-D213 has great potential for enhanced fluoride removal in neutral water. [Display omitted] • Novel binary metal (hydrogen) oxides modified resin (Mg–Zr-D213) for the enhanced removal of fluoride from neutral water. • Mg–Zr-D213 exhibits excellent adsorption capacity for fluoride in neutral water. • A synergistic effect between Mg/Zr metal (hydrogen) oxide nanoparticles and host D213. • Nanoparticles loaded in D213 can selectively adsorb fluoride via specific ligand exchange or metal-ligand interactions. • A binary solution of NaOH–NaCl eluent can effectively regenerate the exhausted adsorbent. [ABSTRACT FROM AUTHOR]

Molecular-imprinted polymers (MIPs) are generally considered as substituents for natural antibodies. MIPs synthesis needs to select appropriate functional monomers. Because of its strong interaction with the template, antibody–antigen complexes can be formed before polymerization. In this paper, myoglobin (Mb)-imprinted polymers with a new sulphoxide monomer (2-(methylsulphonyl) ethyl acrylate, MSEA) as functional monomers were successfully prepared via electrochemically mediated atom transfer radical polymerization (eATRP). At the same time, to solve the problems of low selectivity and large template size limitations, the Mb-imprinted polymers were prepared on the surface of Au electrode decorated with three-dimensional foam graphene (FG) and nano Au (nAu). Cyclic voltammetry, electrochemical impedance spectroscopy, scanning electron microscope and X-ray photoelectron spectroscopy were used to characterize the Au electrode modified with Mb-imprinted polymer (Au/FG/nAu/MIPMSEA). The prepared Au/FG/nAu/MIPMSEA electrode was used as an electrochemical sensor to detect Mb. The results of experiments showed that the proposed biosensor had good selectivity, reproducibility, repeatability and stability. The linear response range was from 1.0 × 10−12 to 1.0 × 10−1 mg·l−1, and the detection limit was 1.21 × 10−13 mg·l−1 (S/N = 3). Compared with other methods for detecting Mb, the sensor had a wider detection range and lower detection limit. [ABSTRACT FROM AUTHOR]

The 2,2′-bipyridine-3,3′-dicarboxylic acid (bpda) and its transition metal complexes including Ni(bpda)2, Zn(bpda)2 and Mn(bpda)2, were synthesized and tested as corrosion inhibitors for a carbon steel in 0.5 M HCl solution by electrochemical tests and surface analyses. The electrochemical results indicate that the inhibition efficiencies increase with the concentration of corrosion inhibitors. The complexes exhibit higher inhibition efficiencies compared to the bpda ligand, among which Ni(bpda)2 is the most effective for inhibiting corrosion. The corrosion morphology observation further evidences the superior corrosion inhibition performance of the three complexes. Fourier transform infrared and X-ray photoelectron spectroscopy analyses confirm the spontaneous adsorption of all four inhibitors on the steel surface, and the adsorption analysis suggests a combined physisorption and chemisorption mechanism. Accordingly, the superior corrosion inhibition performance of the three complexes could be attributed to their good adsorption abilities. [ABSTRACT FROM AUTHOR]

In this article, Mn/I-TiO2 nanocatalyst was prepared by sol-gel method and used as the photocatalyst to discompose the gaseous benzene in the visible light. The crystal phase composition and grain size of the photocatalyst were investigated by X-ray diffraction and Raman, respectively. X-ray photoelectron spectroscopy and ultraviolet-visible diffuse reflectance spectroscope were used to study the surface elements and bandgap width of the photocatalyst. The research findings suggested that the crystal type of all catalysts was anatase. TiO2 nanoparticle doped by Mn/I could reduce its crystallite size and augment lattice distortion because of the formation of oxygen vacancies. The generation rate, migration rate, and disintegration rate of electron-hole pairs were increased by modification of TiO2. Meanwhile, the Mn-TiO2 was recognized with the smallest bandgap among four kinds of catalyst. Mn-TiO2 catalyst exhibited the highest efficiency on gaseous benzene removal (37.86%) among pure-TiO2 (3.33%), I-TiO2 (30.21%), and Mn-I-TiO2 (31.56%) under visible light. Correspondingly, the photocatalytic ability of pure-TiO2, I-TiO2, Mn-I-TiO2, and Mn-TiO2 was 51.25 μg C6H6/(g·h), 424.36 μg C6H6/(g·h), 493.61 μg C6H6/(g·h), and 245.43 μg C6H6/(g·h), respectively. [ABSTRACT FROM AUTHOR]

The 〈 100 〉 crystal-oriented silicon micropillar array platforms were prepared by microfabrication processes for the purpose of electrolyte additive identification. The silicon micropillar array platform was used for the study of fluorinated vinyl carbonate (FEC), vinyl ethylene carbonate (VEC), ethylene sulfite (ES), and vinyl carbonate (VC) electrolyte additives in the LiPF6 dissolved in a mixture of ethylene carbonate and diethyl carbonate electrolyte system using charge/discharge cycles, electrochemical impedance spectroscopy, cyclic voltammetry, scanning electron microscopy, and x-ray photoelectron spectroscopy. The results show that the silicon pillar morphology displays cross-shaped expansion after lithiation/delithiation, the inorganic lithium salt keeps the silicon pillar morphology intact, and the organic lithium salt content promotes a rougher silicon pillar surface. The presence of poly-(VC) components on the surface of FEC and VC electrodes allows the silicon pillar to accommodate greater volume expansion while remaining intact. This work provides a standard, fast, and effective test method for the performance analysis of electrolyte additives and provides guidance for the development of new electrolyte additives. [ABSTRACT FROM AUTHOR]

A novel hemoglobin (Hb) imprinted polymers with CO2 response (CHIPs) were prepared on the surface of Au electrode modified by zinc oxide (CHIPs/ZnO/Au) via electrochemically mediated atom transfer radical polymerization (eATRP). The imprinted polymers were synthesized with Hb both as catalyst and template, and N,N-diethylaminoethyl methacrylate (DEAEMA) as CO2-responsive functional monomer. The obtained CHIPs/ZnO/Au electrode was characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and electrochemical methods. The results showed that CHIPs/ZnO/Au electrode could give higher affinity for the target protein inside a CO2-treated aqueous medium compared to that under N2-treated conditions, which make it a good electrochemical biosensor in the presence of CO2. The biosensor could be successfully applied for the determination of Hb by differential pulse voltammetry (DPV) measurement. The linear response range of CHIPs/ZnO/Au for detecting Hb was 1.0×10−12~1.0×10−1 mg L−1 and the detection limit was 2.1×10−13 mg L−1 (S/N=3). Briefly, the work in this study introduced an easy and non-toxic method for Hb determination under specific conditions and also provided a progressive approach for designing protein imprinted polymers. [ABSTRACT FROM AUTHOR]

Superoxide dismutase (SOD) plays an important role in nearly all living cells. In this study, SOD imprinted poly(ionic liquid)s (SIPILs) were prepared on the surface of the bare Au electrode modified with nano‐palladium and nano‐gold (Au/nPd/nAu/SIPILs). SIPILs was synthesized with 1‐vinyl‐3‐propyl imidazole sulfonate ionic liquids as functional monomers via electrochemically mediated atom transfer radical polymerization (eATRP) catalyzed by SOD. The Au/nPd/nAu/SIPILs was examined by cyclic voltammetry (CV), scanning electron microscope (SEM), energy‐dispersive spectrometer (EDS) and X‐ray photoelectron spectroscopy (XPS). The Au/nPd/nAu/SIPILs was also used as an electrochemical sensor to determine SOD by differential pulse voltammetry (DPV). Under the optimal conditions, the detection range of SOD was from 1.0×10−8 to 1.0×102 mg L−1 with a limit of detection of 8.90×10−9 mg L−1 (S/N=3). Compared with other methods, the sensor based on SIPILs had the broader linear range and lower detection limit. [ABSTRACT FROM AUTHOR]

Hemoglobin (Hb)-imprinted poly(ionic liquid)s (HIPILs) were prepared on the surface of Au electrode modified with gold nanodendrites (Au/ND/HIPILs). HIPILs were synthesized with 1-vinyl-3-propyl imidazole sulfonate ionic liquids as functional monomers via electrochemically mediated atom transfer radical polymerization (eATRP) catalyzed by Hb. The Au/ND/HIPILs electrode was examined by cyclic voltammetry (CV), scanning electron microscope (SEM), and X-ray photoelectron spectroscopy (XPS). The Au/ND/HIPILs electrode was also used as an electrochemical sensor to determine Hb by differential pulse voltammetry (DPV). Under the optimal conditions, the detection range of Hb was from 1.0 × 10−14 to 1.0 × 10−4 mg/mL with a limit of detection of 5.22 × 10−15 mg/mL (S/N = 3). Compared with other methods, the sensor based on poly(ionic liquid)s had the broader linear range and lower detection limit. [ABSTRACT FROM AUTHOR]

A novel composite with in situ synthesized of Ti 2 (Al,Si)C solid solution reinforced Al matrix was fabricated in Ti 2 AlC-Al-Si material system via one-step solid solution and densification by spark plasma sintering method. The relationship between microstructure, phase composition and mechanical properties of composites doped with different Si content (1, 2 and 3 wt%) and fabricated at different sintering temperature (580, 570 and 560 °C) were investigated. The optimal sintering temperature of composites with increasing the Si addition was carefully determined. The interface reaction was effectively regulated under different Si additions. X-ray photoelectron spectroscopy (XPS) and nanoindentation test results reveal that Si formed Si C covalent bond in Ti 2 (Al,Si)C solid solution, and with the increase of Si addition, the hardness and elastic modulus of Ti 2 (Al,Si)C increased by 6.75% and 4.23% in the composites prepared by the three optimal processes. The tensile tests show that when the addition of Si was 2 wt% and the sintering temperature was 570 °C, the composites demonstrated an optimal balance of strength and plasticity. The ultimate tensile strength reached 226 MPa with a strain of 14.33%. Moreover, when added to 3 wt% and the sintering temperature decreased to 560 °C, the composite achieved a significant improvement in elongation. The performance are mainly attributed to the strengthening of Ti 2 (Al,Si)C solid solution and the regulation of interface reaction. • In situ synthesized Ti 2 (Al,Si)C solid solution reinforced Al composite is fabricated by spark plasma sintering method. • The reaction phase TiAl 3 is inhibited by the increase of Si addition and decrease of sintering temperature. • With the increase of Si addition, the hardness and elastic modulus of Ti 2 (Al,Si)C increase by 6.75% and 4.23%. • The Al composite with 20 vol% Ti 2 AlC and 3 wt% Si demonstrates a large strain of 16.33%. [ABSTRACT FROM AUTHOR]

A well-defined block polymer, di-n-butyl ester terminated poly(2,2,3,4,4,4-hexafluorobutyl methacrylate (BTHFMA), was synthesized by the metal-free anionic polymerization. The tetrabutylammonium salt of di-n-butyl malonate was served as functional carbanionic initiator for the anionic polymerization of 2,2,3,4,4,4-hexafluorobutyl methacrylate in a controlled ‘living’ manner for the first time at ambient temperature. The chemical structure of this product was characterized by FT-IR, 1H-NMR, and 13C-NMR. Gel permeation chromatography (GPC) results showed that the molecular weight of BTHFMA ranged from 1025 to 6582 and the molecular weight distributions were fairly narrow (Mw/Mn = 1.12–1.16). By blending the poly(methyl methacrylate-co-butyl acrylate) [P(MMA-co-BA)] with BTHFMA, we minimized the amount of the BTHFMA used while achieving a hydrophobic surface. The surface properties and compositions of the [P(MMA-co-BA)]/BTHFMA blend films were studied by contact angle and X-ray photoelectron spectroscopy (XPS). The results demonstrated that the 5 wt% blends of BTHFMA could obviously increase hydrophobic ability of the blend with a high water contact angle (98.2o) and low surface energy (24.2mN/m). XPS results indicated the fluorine mass content of the surface of the 5 wt% blend was up to 26.6%, which suggested BTHFMA enriched on the surface of the blend. [ABSTRACT FROM AUTHOR]

Abstract: The highly ordered Ag–SrTiO3 nanotube arrays (NTAs) with uniform size were successfully synthesized by a combination of anodic oxidation, hydrothermal process and photocatalytic reduction method. X-ray photoelectron spectroscopy analysis reveals that Ag exists in the form of metallic silver, which is in good agreement with the X-ray diffraction characterization. Moreover, the UV–vis diffuse reflectance spectra indicate that Ag–SrTiO3 NTAs have a strong absorption in the visible region which is attributed to the plasmon resonance of silver nanoparticles. After Ag loading, a further improvement of the photocatalytic activity for hydrogen production was obtained. Based on the above results, a possible electron-hole transfer mechanism was also assumed. [Copyright &y& Elsevier]

Immunoglobulin G (IgG) is related to the occurrence of many diseases, such as measles and inflammatory. In this paper, IgG imprinted polymers (IgGIPs) were fabricated on the surface of nano Au/nano Ni modified Au electrode (IgGIPs/AuNCs/NiNCs/Au) via metal-free visible-light-induced atom transfer radical polymerization (MVL ATRP). The IgGIPs were prepared by IgG conjugated with fluorescein isothiocyanate (FITC-IgG) as both a template and a photocatalyst. After the templates were removed, the photocatalysts (FITC) would not remain in the polymer and avoided all the effect of catalysts on the electrode. The fabricated electrodes were examined by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). Under the optimized conditions, IgGIPs/AuNCs/NiNCs/Au was prepared and used as an electrochemical biosensor. The biosensor could be successfully applied for the determination of IgG by differential pulse voltammetry (DPV) measurement. The results showed that the proposed biosensor displayed a broader linear range and a lower detection limit for IgG determination when it was compared to those similar IgG sensors. The linear range from 1.0 × 10−6 mg L−1 to 1.0 × 101 mg L−1 was obtained with a low detection limit (LOD) of 2.0 × 10−8 mg L−1 (S / N = 3). Briefly, the biosensor in this study introduced an easy and non-toxic method for IgG determination and also provided a progressive approach for designing protein imprinted polymers. Image 1 • A novel immunoglobulin G (IgG) imprinted polymer was prepared. • The preparation was achieved by metal-free visible-light-induced ATRP. • FITC-IgG was both as a template and a photocatalyst. • The IgG imprinted polymers can be used to fabricate a biosensor. • This biosensor demonstrated a linear response with LOD (2.0 × 10−8 mg L−1). [ABSTRACT FROM AUTHOR]

Using chloromethylated polystyrene resin, N , N -diethylaminoethyl methacrylate, and ethylene glycol dimethacrylate as support, functional monomer and cross-linker, respectively, the molecularly imprinted resin (MIR) and non-imprinted resin (NIR) were fabricated by the combination of atom transfer radical polymerization and surface imprinting technique for the selective adsorption of 4-hydroxybenzoic acid (4-HB) from aqueous solutions. The prepared adsorbents were characterized by N 2 adsorption/desorption isotherms, Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The adsorption processes of the 4-HB with MIR and NIR followed pseudo-second-order kinetics, and the adsorption isotherms were appreciably described by the Langmuir model. Furthermore, the adsorption efficiencies of MIR and NIR for different compounds in single and binary solutions proved that MIR exhibited high adsorption capacity and favorable selectivity toward 4-HB over other structurally related organic compounds (i.e., benzoic acid, 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, phenol, and 2-hydroxynaphthalene). In addition, MIR could effectively remove 4-HB from a simulated effluent in a dynamic adsorption experiment. This study illustrates in-depth perspectives on the adsorption mechanisms of 4-HB onto MIR; interactions between the adsorbate and adsorbent were proposed based on the adsorption behaviours and instrumental analyses. The resulting MIR is a promising material for the interference-free adsorbent in the selective adsorption of 4-HB from mixed solutions. Image 1 • A molecularly imprinted resin (MIR) was prepared by the combination of ATRP and surface imprinting technique. • MIR showed high adsorption capacity and favorable selectivity toward 4-HB over other structurally related organics. • This study put forward in-depth perspectives on the adsorption mechanisms of 4-HB onto MIR. [ABSTRACT FROM AUTHOR]

The development of an adsorbent with high adsorption ability and favorable cyclic regeneration performance for the removal of nitrate residues from wastewater is a task of vital importance. To this end, polyacrylonitrile fiber (PANF) was modified with polyethyleneimine (PEI), and alkyl groups were then introduced around the active amine groups to prepare three polymer-based anion exchange fibers (PAN-PEI-3C, PAN-PEI-5C, and PAN-PEI-8C). The novel fibers were characterized using techniques such as scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). The adsorption isotherms of the fibers were best fitted by the Langmuir model, and PAN-PEI-5C exhibited a higher adsorption amount of nitrate (31.32 mg/g) than the other adsorbents. The equilibrium was reached expeditiously (within 10 min), and both pseudo-first-order and pseudo-second-order models could well describe the adsorption kinetics. More attractively, the saturated PAN-PEI-5C could be eluted using a low-concentration (0.3 M) NaCl solution, without any sharp loss of adsorption amount for five consecutive cycles in the presence of dissolved organic matter (DOM). Furthermore, PAN-PEI-5C could effectively adsorb low-concentration nitrate from real secondary effluents in a fixed-bed column experiment. Our work provides a promising and low-cost material for the removal of nitrate residues in practical applications. Image 1 • Novel anion exchange fibers were prepared and used to adsorb low-concentration nitrate from aqueous solutions. • The nitrate adsorption equilibria onto PAN-PEI-5C could be rapidly reached within 10 min. • The saturated PAN-PEI-5C could be efficiently regenerated using a low-concentration (0.3 M) NaCl solution. • PAN-PEI-5C exerted excellent recycling ability in successive adsorption/desorption experiment. [ABSTRACT FROM AUTHOR]

• FePc molecules was successfully immobilized on polystyrene resins to obtain a bioinspired catalyst. • Pyridyl groups grafted on resins served as the axial fifth ligands to coordinate with FePc. • SO 4 − and OH species played the main role in the presence of PMS. • Possible mechanisms were proposed to explain the catalytic performance in PMS activation for TCH degradation. A distinctive catalyst R-N-Fe was synthesized by anchoring iron phthalocyanine (FePc) covalently on chloromethylated polystyrene beads, which were pre-functionalized by 4-aminopyridine (4-ampy). Herein, pyridyl groups grafted on resins act as the axial fifth ligands to coordinate with FePc molecules. The obtained catalyst was characterized using N 2 adsorption-desorption, Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), and zeta potential. The catalytic system based on peroxymonosulfate (PMS) activation was effective and stable for tetracycline hydrochloride (TCH) degradation, and activation energy of the TCH elimination using PMS activated by R-N-Fe was estimated to be 38.79 kJ / mol. Additionally, electron paramagnetic resonance (EPR) measurement combined with three different radical scavengers (ascorbic acid, methanol and tert-butyl alcohol) was conducted to confirm that sulfate radical (SO 4 −) and hydroxyl radical (OH) served as the main active species in the presence of PMS. Current findings suggested that the R-N-Fe/PMS system was a promising approach for the elimination of pharmaceutical compounds from aqueous solution. [ABSTRACT FROM AUTHOR]

A non-transition metal Al doped into VC (1 0 0) nano-flowers with C hybrids on nickel foams (Al-VC@C/NF) was synthesized for the first time as an efficient HER catalyst by chemical vapor carbonization and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), Brunauer–Emmett–Teller (BET), Raman spectra, and x-ray photoelectron spectroscopy (XPS) analyses. This conclusion was confirmed by Density Functional Theory (DFT). [Display omitted] Vanadium carbide (VC) is the greatest potential hydrogen evolution reaction (HER) catalyst because of its platinum-like property and abundant earth reserves. However, it exhibits insufficient catalytic performance due to the unfavorable interaction of reaction intermediates with catalysts. In this work, using NH 4 VO 3 as the main raw material, the flow ratio of CH 4 to Ar was accurately controlled, and a non-transition metal Al-doped into VC (1 0 0) nano-flowers with carbon hybrids on nickel foams (Al-VC@C/NF) was prepared for the first time as a high-efficiency HER catalyst by chemical vapor carbonization. The overpotential of Al-VC@C/NF catalysts in 0.5 M H 2 SO 4 and 1 M KOH at a current density of 10 mA cm−2 are only 58 mV and 97 mV, respectively, which are the best HER performance among non-noble metal vanadium carbide based catalysts. Simultaneously, Al-VC@C/NF exhibits small Tafel slope (45 mV dec-1 and 73 mV dec-1) and excellent stability in acidic and alkaline media. Theoretical calculations demonstrate that doped Al atoms can induce electron redistribution on the vanadium carbide surface to form electron-rich carbon sites, which significantly reduces the energy barrier during the HER process. This work provides a new tactic to modulate vanadium-based carbons as efficient HER catalysts through non-transition metal doping. [ABSTRACT FROM AUTHOR]

In the present work, a SiO 2 @PAA catalyst for NaBH 4 methanolysis composed of silica nanoparticles modified with poly(acrylic acid) has been developed. The morphology and composition of the prepared SiO 2 @PAA catalyst were analyzed with transmission electron microscopy, Fourier transform-infrared spectroscopy, x-ray photoelectron spectroscopy and thermogravimetric analysis. This catalyst showed excellent catalytic performance for methanolysis of NaBH 4. The NaBH 4 methanolysis reaction catalyzed by SiO 2 @PAA showed an average hydrogen generation rate 5.5 times as high as the reaction catalyzed by unmodified SiO 2 and 10.6 times as high as the uncatalyzed reaction, respectively. The activation energy for methanolysis of NaBH 4 catalyzed by this SiO 2 @PAA catalyst was 24.03 kJ/mol. Moreover, although the catalytic activity of SiO 2 @PAA catalyst partially lost after being used, it could be restored after being regenerated by washing with diluted hydrochloric acid solution. [Display omitted] • A metal-free SiO 2 @PAA catalyst composed of SiO 2 nanoparticles modified with poly(acrylic acid) is fabricated. • This catalyst exhibits excellent activity in catalyzing methanolysis of NaBH 4. • The lost activity of used SiO 2 @PAA catalyst could be restored by regeneration in HCl solution. [ABSTRACT FROM AUTHOR]

Carbon nanomaterials-loaded mixed metal oxides are the promising candidates to increase the electrochemical efficacy for glucose monitoring. In this paper, we developed a new hybrid material based on multi-walled carbon nanotubes-supported nickel and cerium mixed oxide nanocomposite (NiCeO x /MWCNTs) through one pot hydrogen co-reduction strategy for non-enzymatic electrochemical glucose sensing. The microscopic and spectroscopic features of as-prepared samples were thorougly characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) techniques. Further, cyclic voltammetry (CV) and chronoamperometry (CA) methods were applied to investigate the electrochemical efficacy of designed electrode towards glucose sensing. The results revealed that, the synergetic effect of nickel and cerium mixed oxides as well as brilliant conductivity of MWCNTs collectively enhanced the electrocatalytic activity of the designed materials for glucose oxidation. Therefore, the fabricated NiCeO x /MWCNTs-based sensor retains the excellent electrochemical efficacy towards glucose sensing as compared to their counterparts including wider linear range (0.007∼0.466 mM and 0.466∼3.44 mM), lower limit of detection (1.8 μM, S/ N = 3), satisfactory sensitivities (271.53 and 429.95 μA mM−1 cm−2) as well as good reproducibility, high stability and selectivity. More specifically, the designed NiCeO x /MWCNTs-based sensor offered brilliant real time applicability to precisely monitor glucose level in diluted human serum samples. This study provided an appealing strategy for the development of simple, efficient and cost-effective non-enzymatic electrochemical glucose sensing platform. [Display omitted] [ABSTRACT FROM AUTHOR]

Dye wastewater is harmful to the ecological environment because of its potential biological toxicity, teratogenicity, carcinogenicity, and mutagenicity. We fabricated a layered graphene oxide (GO) membrane through layer-by-layer (LBL) self-assembly. We used borate to crosslink with GO on a polyethyleneimine (PEI)-coated hydrolyzed polyacrylonitrile (hPAN) support. Fourier transform infrared (FTIR) spectrometry, Raman spectra, and x-ray photoelectron spectroscopy (XPS) confirmed the presence of a crosslinking reaction. The dynamic thermomechanical analysis (DMA) results indicated that the introduction of borate can significantly improve the mechanical properties of the membrane. The Young's modulus, ultimate tensile strength, and proportional limit of borate that was assembled twice as the outermost layer were increased by 110.81%, 62.37%, and 53.72%, respectively, as compared to those of a single-layered GO membrane. Moreover, the pure water fluxes of the layered GO membrane did not obviously decrease with an increase in the number of layers. The flux of the membrane with an outermost layer of borate was greater than that of the previous GO layer. The salt and dye rejection of the membranes was augmented with an increase in the number of layers. For the GO membrane assembled three times, rejection to methyl orange (MO), methylene blue (MB), NaCl, MgCl 2, and MgSO 4 reached 74.02%, 88.56%, 14.55%, 27.50%, and 41.95%, respectively. The use of borate as an inorganic crosslinker can avoid the environmental pollution caused by organic agents, and improve the mechanical properties as well as the filter capability of the layered GO membrane. Therefore, this study presents a novel method of membrane preparation for dye removal. • A layer-by-layer strategy for borate/GO membranes with bionic structures is proposed. • Borate/GO membranes exhibit good mechanical properties and permeation flux. • The removal of dyes and salts may be explained by size sieving and Donnan exclusion. [ABSTRACT FROM AUTHOR]