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Chiral semiconductor nanorod heterostructures with high photocatalysis activity
摘要： Chiral semiconductor nanorods and their heterostructures have attracted intense attention. In this work, it was shown that chiral amino acids on CdSe@CdS semiconductor nanorods (SNR) displayed circular dichroism bands (CD, 200–480 nm). Longer SNRs were found to induce stronger CD intensities, while an increase in the SNR diameter led to a clear CD band redshift. Multi-site post-growth of platinum (Pt) and gold (Au) further enhanced the CD intensity and induced CD band transitions. Electromagnetic calculations revealed that the metal post-growth gave rise to a strong electromagnetic field enhancement, with Pt inducing a stronger enhancement than Au. The optimized chiral multi-sites platinum on SNR displayed higher photocatalytic activities manifested that the deposited metal endowed energy transfer and enhanced the separation of photo-excited electrons and holes. These findings demonstrated that the multi-sites deposited metal provided a method to produce strong optical activity of nanostructures by adjusting the morphology of the semiconductor nanorod.
关键词： circular dichroism,metal growth,heterostructure,semiconductor nanorods
更新于2025-09-23 15:22:29
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Electrochemical synthesis of copper(II) oxide nanorods and their application in photocatalytic reactions
摘要： A new way of synthesizing nanoscale copper oxide particles is described in this work. Oxides of an intermediate metal, such as copper oxide, can be used as an effective semiconductor in the photocatalytic reactions once they are prepared in a special way. The CuO nanorods were synthesized electrochemically under surfactant-free, static conditions. The obtained nanorods have an average length of less than 50 nm. The CuO nanorods were used as a heterogeneous catalyst in an aqueous medium. 2,4-Dichlorophenol (DCP) was used as a probe molecule. The CuO nanorods showed an excellent ability to degrade DCP under visible light and without the need for any auxiliary oxidizing agent.
关键词： CuO,DCP,Visible light,Degradation,Nanorods,Heterogeneous catalyst
更新于2025-09-23 15:22:29
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Synthesis of Mn doped ZnO nanopowders by MW-HTS and its structural, morphological and optical characteristics
摘要： In this study, undoped and Mn doped ZnO nanopowders were synthesized by using the microwave assisted hydrothermal (MW-HTS) method. Doping ratio of Mn in the ZnO was set to 1, 5 and 10%. The effect of Mn concentration on the structural and morphological properties of ZnO nanopowders was investigated using XRD, SEM, XPS and FTIR. XRD results showed that the nanopowders have hexagonal wurtzite structure. The lattice parameters increased with increasing Mn incorporation. SEM images showed that all the samples were formed in nanorod structure and the average diameter of the rods decreased with the Mn concentration. XPS results veri?ed the presence of Mn as a doping element into ZnO crystal lattice and the oxidation states of Mn and Zn. The chemical interactions of ZnO and ZnO:Mn nanopowders were determined for using FTIR spectrum.
关键词： FTIR,Mn doped ZnO,XPS,Microwave assisted hydrothermal,Nanorods
更新于2025-09-23 15:22:29
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The effects of Tb doped ZnO nanorod: An EPR study
摘要： Structural and magnetic behaviors were studied and correlated with each other for Zn1?xTbxO nanorods synthesized by hydrothermal method varying x values from 0.01 to 0.05 with 0.01 step increment. The structural properties of Zn1?xTbxO nanorods were determined by X-ray diffraction tool. All nanorods were found as a single phase with ZnO wurtzite hexagonal structure. The concentration-dependent of lattice parameters, cell volumes, microstrain, stress, dislocation density, the locality of the atoms and their displacements, and bond length in Zn1?xTbxO (where x = 0.0, 0.01, 0.02, 0.03, 0.04, and 0.05) structures were detailed. The particles with varying magnifications were observed as random agglomeration using Scanning Electron Microscope measurement tool. ESR spectra of Zn1?xTbxO were collected at room temperature on a Bruker EMX model X-band spectrometer operating at a frequency of 9.71 GHz. ESR measurements have been performed and analyzed through concentration dependence of the g-factor and the line-widths of pike to pike (ΔHPP) of ESR spectra. Experimental and fitting X-band ESR spectra of Tb doped ZnO nanorods with a different doping concentration of Tb recorded at room temperature were presented.
关键词： Hydrothermal method,Magnetic properties,Nanorods,Zn1?xTbxO
更新于2025-09-23 15:22:29
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Antibacterial and natural room-light driven photocatalytic activities of CuO nanorods
摘要： The present work is aimed to establish the utility of CuO nanorods in diverse fields; from photocatalysis to antimicrobial applications. The CuO nanorods obtained via facile precipitation process (without any surfactant/ligand) depicted excellent photocatalytic activity when examined under natural diffused room light for the complete degradation of the organic pollutant, Rhodamine B. Neither any assistance of any oxidants nor an additional light sources (e.g., with high power, lower wavelength etc.) was required during the whole process. The antibacterial property was also examined for the CuO nanorods. Effects on the microbial growth were noteworthy; the maximum inhibition zone of 37 mm was noted against the Gram-negative E. coli. The most significant effect of the nanorods was depicted in the reduction of 99% of E. coli, 98% of S. flexneri and 93% of S. aureus cells. The suitable activity response of the nanorods establishes the efficacy of the room temperature synthesis process.
关键词： S.flexneri,E.coli,Antimicrobial,Photocatalysis,S. aureus,CuO nanorods
更新于2025-09-23 15:22:29
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Colorimetric detection of copper ions using gold nanorods in aquatic environment
摘要： On the basis of that Cu2+ can accelerate the leaching rate of Au by thiosulfate, a colorimetric, unlabeled and non-aggregating gold nanorod (GNR) probe has been developed for the determination of trace-level Cu2+ in aqueous solutions. Our study demonstrates a high sensitivity and rapid response towards Cu2+ with a detectable range (20–200 nM). E?ect factors such as the ratio of NH3/NH4Cl, the concentration of S2O3 2?, the bath temperature and the heating time were researched to investigate the in?uences on the copper detection process by GNRs sensor. The method studied in this project is highlighted by its high selectivity and high tolerance to interferences, which can be used to detect trace amounts of Cu2+ ions in water samples quickly and sensitively, indicating the potential suitability of copper detection in various applications.
关键词： Gold nanorods,Copper ions,Catalytic leaching,Colorimetric detection
更新于2025-09-23 15:22:29
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Room temperature synthesis of Au NR@Ag2S and Au NR@Ag2S/CdS core-shells using a facile photochemical approach
摘要： In this work, Au nanorods with tunable longitudinal plasmon resonance were synthesized using hydroquinone as complimentary surfactant. Ag2S quantum dots (QDs) were grown directly on Au nanorods using the replacement of cetyltrimethylammonium bromide (CTAB) with 3-Mercaptopropionic acid (MPA) via a novel photochemical approach. X-ray diffraction revealed the presence of Au cubic structure as well as Ag2S monoclinic phase. Fourier-transform infrared spectroscopy, electrochemical impedance spectroscopy and cyclic voltamettery confirmed the successful substitution of CTAB with MPA as an appropriate capping agent for the growth of Ag2S and CdS quantum dots. UV-Vis spectroscopy demonstrated a red shift of plasmon resonance peak from 750 nm up to 835 nm indicating the increase of dielectric constant of surrounded Au nanorods due to the formation of Ag2S QDs as shell. Photoluminescence spectroscopy revealed near Infrared (NIR) emission of Au@Ag2S core-shells as an indication of controllable size of Ag2S during the growth time. Transmission electron microscopy (TEM) images clearly showed the formation of Ag2S QDs as shell around Au nanorods. To indicate the flexibility of current growth method, CdS QDs were also grown on Au@Ag2S core-shells only by addition of Cd precursor to as prepared Au@Ag2S colloidal solution and continuation of UV illumination. The clear and intense visible light emission of the sample together with the NIR emission of Ag2S and gradual red shift of plasmon resonance of Au nanorods with elapsing photochemical treatment time were the indication of successful growth of Ag2S/CdS on Au nanorods. TEM images clearly showed Au@Ag2S/CdS almond shape core-shells. This method has the simplest chemistry and the procedure is very simple, rapid (less than 2 h), energy efficient and scalable for large production of such core-shells.
关键词： Au nanorods,Metal-semiconductor core-shells,Ag2S QDs,Photoluminescence,Electroimpedance spectroscopy
更新于2025-09-23 15:22:29
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Effect of Zinc Oxide nanorods on the structural, thermal, dielectric and electrical Properties of Polyvinyl alcohol /Carboxymethyle Cellulose composites
摘要： ZnO nanorods were prepared by chemical vapor deposition (CVD) have lengths ranging between 104.12 and 307.64 nm and diameters ranging between 21.17 and 55.88nm determined by transmission electron microscopy (TEM). Polyvinyl alcohol/carboxymethyl cellulose nanocomposites and Zinc oxide (ZnO) were prepared by casting method. The prepared samples were characterized by various methods. The results of XRD analysis depict the amorphous nature of these polymer samples and the degree of amorphousity is increased due to the addition process. The interaction of the ZnO NRs with the PVA/CMC blend was identified by Fourier transforms infrared spectroscopy (FTIR). The dispersion of dopant within the polymer matrix was supported by scanning electron microscopy (SEM). DSC and TGA was utilized to study the thermal behavior of the films and the highest conducting polymer material is lower the glass transition temperature. The conductivity and dielectric behaviors were analyzed by complex impedance spectroscopy as a frequency function at different temperature. The ac conductivity is found to obey Jonscher’s law, whereas dc conductivity is seen to exhibit Arrhenius behavior and increases with temperatures and the activation energy of the films with an increasing of ZnO NRs content was decreased. The dielectric properties of pure blend and nanocomposites have been enhanced due to the addition of ZnO NRs and are found to be highly temperature dependent. The frequency exponent (s) have been well fitted with the proposed correlation equation of the barrier hopping model. Significant increase in dc and ac conductivities in these nanocomposites samples makes them a potential candidate for electrochemical device applications.
关键词： AC and Dielectric parameters.,TEM,FT-IR,ZnO nanorods,SEM
更新于2025-09-23 15:22:29
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Photoluminescence Immunosensor Based on Bovine Leukemia Virus Proteins Immobilized on the ZnO Nanorods
摘要： Bovine leukaemia virus (BLV) proteins gp51, which are serving as antigens for specific antibodies against BLV proteins (anti-gp51), were applied as biological recognition part in the design of immunosensor devoted for the determination of anti-gp51. The efficiency of the immobilization of BLV proteins gp51 on ZnO nanorod (ZnO-NR) modified glass (ZnO-NR/glass) surface was evaluated. The formation of antigen-antibody complex on the ZnO/glass modified by the BLV proteins gp51 (gp51/ZnO-NR/glass) was investigated by the determination of changes in ZnO photoluminescence. The applicability of gp51/ZnO-NR/glass in the design of photoluminescence based immunosensor was evaluated. Bovine serum albumin (BSA) was applied for the modification of sensing gp51 layer in order to form gp51&BSA layer with advanced selectivity. Polyallylamine hydrochloride (PAH) was applied in order to improve the immobilization of gp51 and BSA based sensing layer (gp51&BSA) on the surface of ZnO-NR/glass. PAH was applied during the formation of gp51&BSA/PAH/ZnO-NR/glass structure. Some aspects of the mechanism of interaction between biomolecules (gp51, bovine serum albumin (BSA) and anti-gp51) and ZnO-NR during the preparation and action of gp51&BSA/ZnO-NR/glass- and gp51&BSA/PAH/ZnO-NR/glass-based immunosensors have been discussed.
关键词： Bovine leukemia virus (BLV),Photoluminescence,Optical immunosensor,ZnO nanorods,Antigen-antibody complex.
更新于2025-09-23 15:22:29
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Electrical Transport Properties of Thin Film Composed of a-ZnO Nanorods
摘要： Background: Due to its wide band gap, high exciton binding energy and high breakdown strength, the nanostructures of ZnO may find applications for electronic, photonic devices, and high-frequency applications. Objective: The aim of the present work is to study electrical transport of thin film composed of a-ZnO nanorods. Method: Physical vapour condensation method was employed to fabricate the nanorods of ZnO. The morphology of these nanorods was investigated with the help of scanning electron microscope. X-ray diffraction pattern of as-prepared thin film was recorded using X-ray diffractometer. For dc conductivity measurements, four-probe method was used. Result: The as-prepared ZnO nanorods have diameter ranging from 10-20 nm and the length is of order of few hundred nanometers. XRD pattern of film composed of ZnO nanorods suggests the amorphous nature. Temperature dependence of dc conductivity has been studied over the temperature range of (297- 4.2K). For the temperature range of 297-120K, Mott’s three dimensional variable range hopping (VRH) is applied to explain the electrical conduction. For lower temperature range (120 - 4.2K), 2D-variable-range hopping in localized states near the Fermi level may be responsible for the transport of carriers. Conclusion: Variable range hopping mechanism (VRH) has been suggested for the entire temperature range (298-4.2K) on the basis of temperature dependence of dc conductivity data, which changes from 3D to 2D on moving to lower temperatures side (below 125K).
关键词： physical vapour condensation technique,variable range hopping,XRD,ZnO nanorods,SEM,Mott’s parameters,electrical conduction mechanism
更新于2025-09-23 15:22:29