Totally found 145 items.

  • [资讯] One-step synthesis of nitrogen-doped sludge carbon as a bifunctional material for the adsorption and catalytic oxidation of organic pollutants
    Nitrogendoped carbon (NC) materials have been extensively investigated for their great potential applications in adsorption, catalysis, etc. Herein, we report a facile onestep pyrolysis process for NC synthesis using abundant biowaste of excess sludge as carbon source and cheap precursor of urea as nitrogen source. The developed materials were evaluated for organic pollutants removal through adsorption and catalytic oxidation by peroxymonosulfate (PMS) activation. Experimental results demonstrated that nitrogen doping significantly affected the elemental composition and microstructure of NC, leading to improved adsorption capability as well as PMS activation activity for methylene blue (MB) removal. The adsorption capacity for MB reached 35.831 mg g1 over NC700 sample (NC prepared at 700 C). In MB catalytic oxidation experiments, effects of sample calcination temperature, catalyst dosage, PMS loading, and coexisting ions were investigated. Under optimal reaction conditions, 98.70% of MB could be removed in 20 min. Through radical quenching and electron spin resonance (ESR) tests, it was confirmed that singlet oxygen (1O2) was the main reactive species for MB degradation. Additionally, NC700 performed well in recycle studies without significant efficiency loss. Other typical organic pollutants including malachite green (MG), methyl orange (MO), bisphenol A (BPA), phenol (PE), and sulfamethoxazole (SMX) could also be removed using NC700 as adsorbent and catalyst. These features manifest that excess sludgederived NC could be a promising material for organic pollutants remediation.
  • [资讯] Synthesis and characterization of PEG-functionalized graphene oxide as an effective pH-sensitive drug carrier
    In the present work, PEG4000 as a hydrophilic polymer was conjugated to the surface of graphene oxide (GO) for effective drug loading and targeting release of doxorubicin. The synthesized nanohybrid was characterized with scanning electron microscope (SEM), Xray diffraction spectroscopy (XRD) and Fouriertransformed infrared spectroscopy (FTIR). Doxorubicin as an anticancer drug was immobilized on the nanohybrid surface, and the release profile at two diverse pH besides the MTT assay was investigated. The IC 50 value for the nanohybrid obtained was 0.31 gmL. In this work, PEG4000 as a biocompatible polymer grafted on the GO surface to increase the biodispersibility of the drug carrier in a biological environment, but it is the first report of PEG 4000GO nanohybridbased drug carrier.
  • [资讯] Synthesis and characterization of cadmium-bismuth microspheres for the catalytic and photocatalytic degradation of organic pollutants, with antibacterial, antioxidant and cytotoxicity assay
    CadmiumBismuth microspheres (CdSBi2S3) were prepared by facile solvothermal method with polyvinylpyrrolidone (PVP) employed to control the morphology of CdSBi2S3. The product was characterized using Xray diffraction (XRD), scanning electron microscope (SEM), diffuse reflectance UVvis spectrophotometer and surface area of CdSBi2S3 was determined by BET analyzer. It was observed that CdSBi2S3 spheres exhibited good catalytic activity for the reduction of 4nitrophenol. The photocatalytic application of CdSBi2S3 was evaluated for the photocatalytic degradation of environmental pollutants such as methyl orange, and methyl green under UVvisible light irradiation and it demonstrated good photocatalytic activity. Furthermore, we studied the antioxidant activity of CdSBi2S3 and it was observed that CdSBi2S3 showed antioxidant activity at all tested concentrations (5, 3 and 1 mgmL). Antimicrobial activity of CdSBi2S3 microspheres was also studied for microbial control and the tested nanospheres proved to be exceptional antibacterial agent against tested Grampositive and Gramnegative bacteria. CdSBi2S3 microspheres also exhibited significant cytotoxicity activity against HCT 116 (Human colon colorectal tumor) cell line. Our results indicate that CdSBi2S3 is good photocatalyst with several biological activities. The effective preparation method of CdSBi2S3 could be useful to design and fabricate the novel photocatalyst which may have several applications in the field of catalysis and in the medicine.
  • [资讯] Synthesis, structural characterization and electrical conduction mechanism of the new organic-inorganic complex: (((C3H7)(4)N)FeCl4)
    A new organic inorganic hybrid material, tetrapropylammonium tetrachloferrate, has been synthesized and characterized by singlecrystal Xray diffraction, thermal analysis, vibrational and impedance spectroscopies. The single crystals were obtained by slow evaporation of an aqueous solution of the reactants at room temperature. The (C3H7)(4)NFeCl4 compound crystallizes in the orthorhombic system (Pbca space group). The structural analysis shows the presence of cavities arranged in the 100 direction. It is formed by six cations ((C3H7)(4)N) which accommodate the anionic group (FeCl4()) The differential scanning calorimetry (DSC) indicates the presence of three phase transitions, located at T 333, 368 and 398 K. Besides, the impedance spectra were explored with an equivalent circuit including a parallel combination of resistance and fractal capability. From Jonschers power law, the Correlation Barrier Hopping (CBH) and the Nonoverlapping Small Polaron Tunneling (NSPT) model prevailed the conduction mechanism in the title compound. Furthermore, the electrical modulus analysis shows the nonDebye type conductivity relaxation.
  • [资讯] Species synchrony and its drivers neutral and nonneutral community dynamics in fluctuating environments.pdf
    We report a methodology using machine learning to capture chemical intuition from a set of (partially) failed attempts to synthesize a metal-organic framework. We define chemical intuition as the collection of unwritten guidelines used by synthetic chemists to find the right synthesis conditions. As (partially) failed experiments usually remain unreported, we have reconstructed a typical track of failed experiments in a successful search for finding the optimal synthesis conditions that yields HKUST-1 with the highest surface area reported to date. We illustrate the importance of quantifying this chemical intuition for the synthesis of novel materials.
  • [资讯] First synthesis of poly(furfuryl) alcohol precursor-based porous carbon beads as an efficient adsorbent for volatile organic compounds
    Furfuryl alcohol (C 5 H 6 O 2 ) (FA) was used as the precursor for the synthesis of approximately 1.0 mm sized polymeric beads (PFAB) via suspension polymerization. The polymeric beads were carbonized and activated to synthesize porous carbon beads (PFABCA) as an efficient adsorbent for gaseous volatile organic compounds (VOCs). Surface characterization tests revealed the material to be predominantly microporous with the specific surface area measured to be 446 m 2 g. Raman measurements revealed a graphitic characteristics of PFABCA. Adsorption tests were performed in a fixed tubular packed bed adsorber under different operating conditions: amounts of adsorbents (26 g), gas flow rates (0.20.4 standard cc per min), adsorption temperatures (4060 C), VOC concentrations (200053,300 ppm) and types of VOCs (toluene and benzene). The tests revealed high adsorption capacities of the synthesized material i.e., 515 and 350 mgg for toluene and benzene, respectively at 50 C. This study has clearly shown that the biomassbased environmentally benign FA can be a potential alternative precursor to the synthetic petrobased polymers presently used for preparing carbonbased adsorbents.
  • [资讯] Facile synthesis of dual-functionalized microporous organic network for efficient removal of cationic dyes from water
    A facile onestep anhydride hydrolysis strategy was rationally designed to synthesize a novel dualfunctionalized microporous organic network (MON4COOH) with enriched naphthalene and carboxyl groups for efficient removal of cationic dyes. The predesigned electrostatic, hydrogen bonding, and hydrophobic interaction sites on MON4COOH led to the complete removal of three typical cationic dyes methylene blue, malachite green and crystal violet (25 mg L 1 for each) within 20 s and gave their maximum adsorption capacities of 2564, 3126 and 1114 mg g 1 , respectively. The adsorption of these cationic dyes fitted well with pseudosecondorder kinetic and Langmuir adsorption models. The adsorption kinetics and capacities of these cationic dyes on MON4COOH were much faster and higher than many other reported adsorbents. The negatively charged MON4COOH also gave much faster adsorption kinetic and larger adsorption capacity for cationic (methylene blue, malachite green and crystal violet) dyes than anionic dye. The excellent flowthrough water treatment ability and reusability also made MON4COOH highly potential for the remediation of cationic dyes polluted water. This work provided a feasible way to design and synthesize dualfunctionalized MONs for efficient adsorption and elimination of environmental pollutants from water.
  • [资讯] Synthesis and modification of moisture-stable coordination pillared-layer metal-organic framework (CPL-MOF) CPL-2 for ethylene/ethane separation
    Adsorptive separation of ethyleneethane (C2H4C2H6) binary mixture has growing interest in petrochemical industries compared to the conventional energyintensive cryogenic distillation. Development of moisturestable materials with high selectivity is of great importance to accomplish C2H4C2H6 separation. Coordination pillaredlayer metalorganic framework (CPLMOF) CPL2 was synthesised at room temperature, and then modified by silver ions impregnation to enhance the selectivity towards ethylene over ethane. The synthesised CPL2 and AgCPL2 MOFs have excellent moisture stability which was confirmed by the dynamic water vapour adsorption analysis under 90% relative humidity, showing no significant framework decomposition, even at 50 degrees C. The calculated selectivity based on gravimetric singlecomponent gas adsorption experiments shows the significantly improved C2H4C2H6 selectivity from 1.4 to 26.1 after loading 10 wt.% (theoretical) of silver ions on CPL2. Breakthrough experiments for C2H4C2H6 (1:1, vv) mixture suggest that both CPL2 and 10 wt.% AgCPL2 can achieve the binary mixture separation, and 10 wt.% AgCPL2 shows relatively better dynamic separation performance compared to parent CPL2. The good adsorption selectivity and moisture stability allow CPLMOF to be a class of promising porous materials for further exploitation in the separation of C2H4C2H6 mixtures. Additionally, the method presented here can potentially be extended to other CPLs with different pore sizes for alkenealkane separations.
  • [资讯] Plant-mediated biosynthesis of iron nanoparticles-calcium alginate hydrogel membrane and its eminent performance in removal of Cr(VI)
    Iron nanoparticles (FeNPs)calcium alginate (CaAlg) hydrogel membrane was biosynthesized using green tea extract. Characterization of ultraviolet and visible (UVVis) spectra, Scanning Electronic Microscopy (SEM) and Transmission Electron Microscope (TEM) of FeNPs and FeNPsCaAlg hydrogel membrane confirmed that the FeNPsCaAlg hydrogel membrane is covered by FeNPs and the FeNPs are spherical in shape and the average particle size is 4.96 2.03 nm. The composite membrane shows a eminent performance in removing chromium Cr(VI) from wastewater. The FeNPsCaAlg hydrogel membrane (0.6 g) can remove as high as 99.5% of 1 mgL (50 mL) Cr(VI) at room temperature (23 C) and original pH (5.41) within 10 min. It is confirmed that the combination of biosynthesized FeNPs and CaAlg hydrogel membrane show synergistic effect on removal of Cr(VI). Furthermore, the superiority and complementary mechanism of the composite membrane were proposed with the aid of Xray photoelectron spectroscopy (XPS).