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In-Situ covalent synthesis of gold nanorods on GO surface as ultrasensitive Raman probe
摘要： In this paper, using thiolated graphene oxide (GO‐O‐SH) as substrate, gold nanorods (AuNRs) covalently linked to the GO surface by in‐situ seed growth method were first reported. The as‐prepared composites were characterized by UV–vis spectrum, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT‐IR). Experimental results indicated that the introduction of short flexible organic chain between GO and AuNRs contributed to the homogenous synthesis of gold rods, and uniform gold nanorods with aspect ratio within 3~8 were covalently linked to the surface of GO with high stability and yield. The strategy represented an outstanding improvement in comparison to the traditional route for fabricating the two GO@AuNRs composites. Furthermore, based on coupling of nanomaterials, the composites could act as high sensitive Raman probe with limit of detection (LOD) reaching 1 × 10?12 M.
关键词： covalent synthesis,Raman probe,graphene oxide (GO),gold nanorods
更新于2025-09-23 15:23:52
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Microwave plasma torch synthesis of Zn Al oxides as adsorbent and photocatalyst for organic compounds removal
摘要： Zn-Al based oxides were synthesized using a microwave plasma torch (MPT) in which the precursors were introduced into the reaction chamber either upstream or downstream of the inlet, respectively. Zn\Al layered doubled oxide (LDO) samples with a layer-by-layer structure obtained from the downstream path exhibited high adsorption capacity for anionic species, i.e., acid red 27 (AR27) and methyl orange (MO) dyes through hydrogen bonding and electrostatic interaction. The adsorption behavior follows a pseudo-second-order model and the Langmuir isotherm, suggesting that chemisorption of adsorbate on the adsorbent surface plays a significant role. Zn\Al oxide (ZAO) powders prepared from the upstream path show high crystallinity, enabling them to photocatalytically degrade methyl blue (MB) dye solution under UV and visible light irradiation. The crystallization mechanisms for ZAO and LDO prepared by the MPT method were also proposed in this study. In summary, the MPT process is a facile, rapid, scalable, and cost-effective method for synthesizing of Zn\Al based materials for many practical applications.
关键词： Photocatalyst,Zn-Al oxide,Adsorbent,Microwave Plasma Torch Synthesis
更新于2025-09-23 15:23:52
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In situ synthesis of gold nanoparticles on pseudo-paper films as flexible SERS substrate for sensitive detection of surface organic residues
摘要： Surface enhanced Raman scattering (SERS) substrates that can be attached to rough, irregular surfaces and directly collect samples is especially useful for the detection of surface organic residues. Herein, novel AuNPs-pseudo-paper films (APPFs) with uniform structure, flexible properties and wicking capabilities were first fabricated and used as SERS substrate for the sensitive detection of surface pesticides residues. Gold nanoparticles (AuNPs) were in situ synthesized on pseudo-paper films (PPFs) by iterative seeding method to create lots of “hot-spots”, accordingly exhibiting high SERS activity (SERS enhancement factor of 3.02×106). By virtue of polyethylenimine (PEI) grafted onto the dissolved microcrystalline cellulose (MCC), AuCl4- and AuNPs can firmly be bonded to the surfaces of PPFs. The prepared APPFs show high reproducibility (relative standard deviation of 6.13 %), which is attributed to the uniform surface of the films. The fabricated APPFs SERS substrate allows rapid detection of surface pesticides residues by a facile “swabbing-measure” detection mode avoiding tedious and time-consuming sampling and separation processes. Based on their inherent SERS spectra, thiram, parathion methyl, and malachite green (MG) can be simultaneously detected on apple peel, which demonstrates the potential applicability of this developed protocol for surface organic residues analysis in agriculture and food security.
关键词： surface pesticides residues,pseudo-paper,in situ synthesis,SERS
更新于2025-09-23 15:23:52
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Modeling and optimization of characterization of nanostructure anodized aluminium oxide membranes
摘要： This study indicates the importance of statistical analysis and modeling to investigate the synthesis and optimization of anodized aluminium oxide (AAO) properties for template-assisted synthesis of nanostructure particles. The response surface methodology was used to optimize pore size and porosity of AAO. The impacts of four main parameters including type of acidic electrolyte, concentration of acid, bath temperature and electrical potential of anodization on characterization of AAO were investigated. Statistical analysis showed that the linear and quadratic terms of these variables had significant effects. Based on the statistical analysis, a possible mechanism of the anodization was proposed. The proposed mechanism helped us to develop an analytical model. The analytical model could predict the experimental results with an appropriate accuracy. Results indicated the rate-limiting reaction in anodization process is water dissociation which was conducted at the pore bottom of the AAO. In addition, concentrated electrical field at pore base induced water splitting so that the activation energy of water dissociation decreased ten times and reached to 9898.5 J/mol.
关键词： Statistical analysis,Anodized aluminium oxide,Electrochemical synthesis,Pore perforation,Nanoporous materials
更新于2025-09-23 15:23:52
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Ultrasmall Au-Ag Alloy Nanoparticles: Protein-directed Synthesis, Biocompatibility and X-ray Computed Tomography Imaging ?
摘要： The ultrasmall sizes of nanoparticles have attracted significant attention for potential application in the fields of catalysis and nanomedicine. Herein, we reported on the green preparation and X-ray computed tomography (CT) imaging of ultrasmall bimetallic bovine serum albumin-directed gold-silver (Au-Ag@BSA) nanoparticles (2–4 nm) using BSA as a stabilizing and template-directed agent. Further, the effects of synthesis condition were systematically explored to prepare products by adjusting the different molar ratios of Au/Ag. The resulting Au-Ag@BSA nanoparticles exhibited the spherical shape, well-dispersed ability, as well as long-term room-temperature stability. The cytotoxicity effects of Au-Ag@BSA nanoparticles on A549 and MCF-7 cells were compared with those of individual Ag nanoparticles, and the results indicated lower cytotoxicity effect by Au-Ag@BSA nanoparticles. Furthermore, the in vivo toxicity of Au-Ag@BSA nanoparticles was investigated in the early-stage zebrafish embryos. The results indicate that there are not any obvious changes of survival and hatching percentages at multiple growth stages (4-120 hpf) even a high level of Au-Ag@BSA nanoparticles (up to 80 mM), revealing the good biocompatibility. Interestingly, a rational design of Au/Ag molar ratio (3:2) surprisingly possessed the enhanced CT performances compared to the Au nanoparticles and iohexol. Accordingly, this study highlights a new prospect in the green preparation of ultrasmall alloy nanomaterials with good biocompatibility and will be of great interest in developing CT contrast agent, catalyst as well as drug delivery carrier.
关键词： green synthesis,Au-Ag@BSA nanoparticles,biocompatibility,zebrafish embryos,enhanced CT imaging
更新于2025-09-23 15:23:52
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One-step preparation of Bi4O5BrxI2?x solid solution with superior photocatalytic performance for organic pollutants degradation under visible light
摘要： Highly e?cient photocatalyst is the demand for controlling environmental pollution, especially the toxic and refractory organic contaminants. Herein, a series of bismuth-rich Bi4O5BrxI2?x solid solution photocatalysts were prepared through a one-step solvothermal method by adjusting the molar ratio of Br/I, which can e?ectively degrade organic pollutants of phenol and Rhodamine B (RhB). The structure and morphology of the photocatalysts were characterized by X-ray di?raction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), transmission electron microscope (TEM) and high resolution transmission electron microscope (HRTEM). The results indicated that Bi4O5BrxI2?x solid solution photocatalysts were successfully synthesized. The obtained samples showed superior photocatalytic activities toward phenol and RhB under visible light irradiation. Besides, the photocatalytic performances can be optimized by changing the ratio of Br/I. When the ratio of Br/I was 1:1, the obtained Bi4O5BrxI2?x solid solution exhibited the highest photocatalytic performance, which was nearly 6.4 and 8.5 times higher than that of pure Bi4O5Br2 and Bi4O5I2 for phenol degradation, respectively. The enhancement can be ascribed to the high e?cient separation of photogenerated electron-hole pairs in Bi4O5BrxI2?x solid solution, which was con?rmed by the corresponding optical and photoelectrochemical characterizations.
关键词： One-step synthesis,Photocatalytic,Bi4O5BrxI2?x solid solution,Bismuth-rich
更新于2025-09-23 15:23:52
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Synthesis, characterization and DFT analysis of new phthalocyanine complexes containing sulfur rich substituents
摘要： Nine new tetrasubstituted metallophthalocyanines (MPc) bearing sulfur rich substituents on peripheral positions were synthesized and fully characterized. The new MPc compounds contain Co2+, Ni2+ and Cu2+. The photochemical and electrochemical properties of the new molecules were investigated. In addition to this investigation, a comparative study took place on the effect of the type of terminal ligand on properties of the MPc compound. Theoretical studies (DFT) were, also carried out in order to support the corresponding experimental results.
关键词： Cobalt,Copper,Nickel,Microwave synthesis,Phthalocyanines,DFT calculations
更新于2025-09-23 15:23:52
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A SHG-active manganese coordination polymer with noncentrosymmetric structure based on achiral carboxyphosphinate ligand
摘要： The hydrothermal reaction of MnSO4 with the achiral 2-carboxyethyl(phenyl)phosphinate ligand (H2L) afforded a 2 D coordination polymer manganese phosphinate, [Mn(HL)2]n (1) (H2L ? 2-carboxyethyl(phenyl) phosphinic acid). It contains two types of dimeric ring motifs, which can generate a layer structure through edge-sharing. The interlayer stacking by C-H … p interactions between the C-H groups of the phenyl rings of HL- and the phenyl rings of the adjacent layers results in its crystallization in a noncentrosymmetric crystal structure with (43)2(46(cid:2)66(cid:2)83) topology. Compound 1 shows a second harmonic generation response that is 0.8 times that of urea. The luminescence spectrum indicates an emission maximum at 457 nm, attributed to an intra-ligand emission state.
关键词： noncentrosymmetric structure,manganese,coordination polymer,Hydrothermal synthesis
更新于2025-09-23 15:23:52
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Synthesis of Bismuth Ferrite BiFeO <sub/>3</sub> by solution combustion method
摘要： In this work we describe the synthesis of bismuth ferrite BiFeO3 (BFO) by the method of combustion in solution. Using the techniques of X-ray diffraction (XRD) together with its refinement Rietveld reveals the existence of a distorted rhombohedral perovskite structure (Space group-R3c). The average size of the BFO crystallite was estimated from the half-height width of the X-ray diffraction peaks using the Scherrer’s equation. The morphology of the prepared sample was determined by scanning electron microscopy (SEM) and stoichiometry ratio of BFO was determined by energy dispersive spectroscopy (EDS)
关键词： BFO,X-Ray Diffraction (XRD),Combustion synthesis,Multiferroics
更新于2025-09-23 15:23:52
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Visible-light-initiated one-pot clean synthesis of nitrone from nitrobenzene and benzyl alcohol over CdS photocatalyst
摘要： The controlled visible-light mediated conversion of nitroaromatics to versatile nitrogen-containing intermediates is of great significance but still remains a challenge. Herein, we report for the first time a facile visible-light-initiated one-pot strategy for clean and efficient synthesis of nitrone from nitrobenzene and benzyl alcohol. It integrates the controlled photocatalytic reduction of nitrobenzene to phenylhydroxylamine by photogenerated electrons with the selective photocatalytic oxidation of benzyl alcohol to benzaldehyde by photoinduced holes over a low-cost CdS photocatalyst with a suitable reduction capability, followed by spontaneous condensation of the as-formed hydroxylamine and aldehyde at ambient pressure and room temperature. Furthermore, by modulating cocatalyst and illumination time, for the conversion of the same reactants, the other two useful nitrogen-containing compounds, imine and secondary amine, were also successfully synthesized. The reaction mechanisms for flexible synthesis of the three target products are proposed.
关键词： One-pot strategy,Clean synthesis,Photocatalysis,Nitrobenzene and benzyl alcohol,Nitrone,Imine and secondary amine
更新于2025-09-23 15:23:52