Flower-like 3D Research Articles

Self-assembly of poly(p-phenylene)-based flower-like 3D micro-nanostructures

Poly(2,5-dioctyloxy-p-phenylene) was fabricated into Chrysanthemum-like, rose-like, and coil-like micro-nanostructures and porous sponge-like three-dimensional (3D) network via solution-phase self-assembly by two types of phase separations (continuous and dispersed phases) occurred by the dissolution of polar MeOH vapor and nonpolar hexane vapor into the polymer solutions, respectively. Morphological changes of polymers produced significant changes in the optical properties. It was concluded that the choice of a good solvent and nonsolvent vapor for hairy-rod polymers is a facile way to design and fabricate various super-macromolecular architectures.

Preparation of MgO nanomaterials by microemulsion-based oil/water interface precipitation

This paper presented a novel microemulsion-based method for the preparation of MgO nanomaterials. Briefly, in a paraffin-in-water microemulsion system, we firstly synthesized Mg5(CO3)4(OH)2·4H2O/paraffin composites, the precursor of MgO, via an interface-controlled homogenous precipitation. By calcinating the composite precursor at different temperatures, MgO nanomaterials with varied morphologies could be obtained. A flower-like 3D hierarchical structure was achieved when applying lower calcination temperatures, which indeed preserves the morphology of the composite precursor. While at higher calcination temperatures, one can get the well-defined MgO nanoparticles. The prepared materials were thoroughly characterized by XRD, SEM and BET methods, and their application as adsorbents to remove Congo red from wastewater was demonstrated.

High open voltage and superior light-harvesting dye-sensitized solar cells fabricated by flower-like hierarchical TiO2 composed with highly crystalline nanosheets

The morphology, microstructure and crystallography of titanium dioxide (TiO2) have great effect on the photoelectric performance of dye-sensitized solar cells (DSSCs). Herein, flower-like 3D TiO2 microstructures based on well-defined high-crystalline nanosheets are synthesized through a facile hydrothermal method. Especially, morphological evolution process and mechanism of this hierarchical structure are investigated. Due to the highly crystalline nature and smaller surface area of these nanosheets, the corresponding device shows an extremely high open-current voltage up to 0.84 V, which results from the less electron recombination. When applied as a scattering layer on top of the nanoparticle layer, the power conversion efficiency (PCE) can be significantly improved and give birth to a PCE value of 9.6%, which is 24.6% higher than that of an analogous device using nanoparticles (NP) (7.7%). As reflected by diffusion reflection spectra, intensity of the modulated photocurrent/photovoltage spectroscopy (IMPS/IMVS) and electrochemical impedance spectra (EIS), this hierarchical structure can not only enhance light harvesting, but also reduce electron recombination, facilitate electron transport and improve electron collection efficiency.

Microfluidic paper-based analytical device for photoelectrochemical immunoassay with multiplex signal amplification using multibranched hybridization chain reaction and PdAu enzyme mimetics

Combining multibranched hybridization chain reaction (mHCR), the photoelectrochemical (PEC) immunosensor was fabricated with a microfluidic paper-based analytical devices using different sizes of CdTe quantum dots (QDs) sensitized flower-like 3D ZnO superstructures as photoactive materials. Firstly, 4-aminothiophenol (PATP) functioned ZnO was anchored on gold-paper working electrode. With the aid of PATP, large-sized CdTe-COOH QDs (QDs1) were conjugated onto the ZnO surface because of the formation of a strong bond (Zn-S) between the thiol of PATP molecule and the ZnO, and the remaining amino group formed an amide bond with carboxylic acid group capping CdTe. Then the small-sized CdTe-NH2 QDs (QDs2) were modified on the QDs1 by forming amide bond, which leaded to a very strong photocurrent response because of the formation of cosensitized structure. The designed mHCR produced long products with multiple branched arms, which could attached multiple PdAu nanoparticles and catalyze the oxidation of hydroquinone (HQ) using H2O2 as anoxidant. Double strands DNA with multiple branched arms (mdsDNA) was formed by mHCR. In the presence of carcinoembryonic antigen (CEA), PdAu-mdsDNA conjugates-labeled CEA antibody was captured. The concentrations of CEA were measured through the decrease in photocurrent intensity resulting from the increase in steric hindrance of the immunocomplex and the polymeric oxidation product of HQ. In addition, the oxidation product of HQ deposited on the as-obtained electrode, which could efficiently inhibit the photoinduced electron transfer. Under optimal conditions, the PEC immunosensor exhibited excellent analytical performance: the detection range of CEA was from 0.001 to 90ngmL−1 with low detection limit of 0.33pgmL−1. The as-obtained immunosensor exhibited excellent precision, prominent specificity, acceptable stability and reproducibility, and could be used for the detection of CEA in real samples. The proposed assay opens a promising platform of clinical immunoassay for other biomolecules.

One-step synthesis of flower-like carbon-doped ZrO2 for visible-light-responsive photocatalyst

Carbon-doped ZrO2 photocatalysts with three-dimensional (3D) flower-like architecture were successfully prepared by one-step sol–gel-hydrothermal process using zirconatrane precursor for use as a high-performance material for the methylene blue (MB) degradation and the enhanced photoelectrochemical (PEC) properties compared with zero-dimensional ZrO2 nanoparticles and commercial TiO2 nanoparticles (P25). These mesoporous microflower structures consisted of ZrO2 nanopetals, implying good intercrystalline connections and effective light absorption. The synergy of carbon doping and flower-like hierarchical 3D architecture greatly promoted the photocatalytic efficiency for MB degradation under visible light. In view of these advantageous features inherited from the carbon-doped ZrO2 with flower-like structure can be used as photoanode materials. A high photoconversion efficiency of 3.17% was achieved from flower-like carbon-doped ZrO2, which increased by 575% and 1168% compared with those of the PEC devices based on ZrO2 nanoparticles and P25, respectively.

Preparation of graphene supported flower-like porous 3D ZnO–NiO ternary composites for high capacity anode materials for Li-ion batteries

Flower-like ZnO–NiO mesoporous architectures were synthesized through annealing the zinc hydroxide carbonate–nickel hydroxide carbonate composite precursor, which was prepared via a one-pot hydrothermal route. More importantly, we successfully prepared flower-like porous ZnO–NiO/graphene composites by introducing flexible graphene into the flower-like porous ZnO–NiO. In addition, we explore the application of the 3D flower-like ZnO–NiO composite mesoporous architectures and flower-like porous ZnO–NiO/graphene composites as anode materials for lithium ion battery. Electrochemical study presented that the as-prepared flower-like porous ZnO–NiO/graphene composites demonstrate excellent electrochemical performance and cycling stability. The first discharge capacity is 1205.7mAh/g at a high current density of 300mA/g. After 50 cycles, the reversible capacity is 452.7mAh/g at a current density of 300mA/g and the coulomb efficiency reaches at 99%.The improved electrochemical performances are mainly attributed to its morphological characteristics of mesoporous, nanosheet self-assembling architectures, as well as the addition of graphene. These results suggest that such 3D flower-like porous ZnO–NiO/graphene composites are promising materials for lithium ion battery.

Hierarchically mesoporous flower-like cobalt oxide/carbon nanofiber composites with shell–core structure as anodes for lithium ion batteries

Hierarchically mesoporous flower-like Co3O4/carbon nanofiber (Co3O4/CNF) composites with a shell–core structure for use as an anode material for lithium ion batteries were prepared through electrophoretic deposition on electrospun CNF, followed by annealing in air. The flower-like Co3O4 shell on the surface of the CNF core formed a highly porous three-dimensional (3D) structure with a large surface area of 332m2g−1 and a mesoporous surface area of 176m2g−1. The Co3O4 shells provided abundant inner spaces through the development of mesopores, which facilitated the diffusion of lithium ions and also suppressed the volume expansion to some extent, leading to high specific capacities. The rate capability was also increased as a result of CNF having a one-dimensional pathway, which enhanced the electrical conductivity and structural stability. After the initial capacity of 1446mAhg−1, the specific capacity leveled off at 911mAhg−1 without showing capacity fading even after 50 cycles. Exceptional percent recovery was observed with the flower-like mesoporous 3D morphology. The electrochemical stability was maintained through the cushioning effect created by the CNF via elastic deformation when the Co3O4 shell expanded its volume and compressed the CNF radially.

Tunable morphology from 2D to 3D in the formation of hierarchical architectures from a self-assembling dipeptide: thermal-induced morphological transition to 1D nanostructures

Construction of complex three-dimensional (3D) architectures through hierarchical self-assembly of peptide molecules has become an attractive approach of fabricating multifunctional advanced materials due to their various potential applications in bionanotechnology. This paper describes the tunable formation of flower-like 3D hierarchical architectures of intricate morphology from a simple self-assembling dipeptide phenylalanine–tyrosine with a facile preparative method by applying a range of voltages through a drop of peptide solution. The fine-tuning of voltages and their application time enable to produce morphological changes of the microstructures from 2D to 3D and also control their formation. The morphology has been characterized by the gradual change in the height-to-diameter ratio of the microstructures with change in the applied voltages. Moreover, these microstructures show significant thermal stability over a wide range of temperatures, whereas adequately high temperature promotes the morphological transformation of the microstructures into different types of ultrathin 1D nanostructures such as nanowires, nanofibrils, etc. Furthermore, we have suggested a possible growth model for the fabrication of unique hierarchical architectures through diffusion-limited aggregation mechanism.

Direct growth of flower-like 3D MnO2 ultrathin nanosheets on carbon paper as efficient cathode catalyst for rechargeable Li–O2 batteries

Structure and working mechanism of the MnO2/CP air electrode.

Electrochemiluminescence PSA assay using an ITO electrode modified with gold and palladium, and flower-like titanium dioxide microparticles as ECL labels

We report on the synthesis of flower-like 3D titanium dioxide (fl-TiO2) using a hydrothermal method. This material possesses a large specific surface and displays an electrochemiluminescence (ECL) intensity that is much stronger than the one of TiO2 nanoparticles having smooth surfaces. It was used to label the secondary antibody in a sandwich immunoassay. A thin layer of metallic gold (Au) and palladium (Pd) was deposited on an indium tin oxide (ITO) electrode by code-position at a potential of 0.2 V in the respective chloride solutions. The Au/Pd-modified ITO electrode showed good conductivity. An ECL based immunoassay for the prostate specific antigen (PSA) was then worked out by immobilizing the first antibody on the Au/Pd layer on the ITO electrode, then exposing the electrode to a sample containing PSA, then forming the sandwich with the fl-TiO2 labeled secondary antibody, and finally measuring the intensity of ECL at a potential of −1.5 V. This ECL sensor has a response range that extends from 0.001 to 600 ng∙mL−1, a lower detection limit of 0.32 pg∙mL−1, good specificity, acceptable stability and good reproducibility. It gave satisfactory results when used for the determination of PSA in (spiked) diluted solutions of human serum.

A novel rose flower-like SnO hierarchical structure synthesized by a hydrothermal method in an ethanol/water system

Abstract Rose flower-like SnO hierarchical 3D architectures consisting of well-ordered microsheets were synthesized by a template-free and surfactant-free hydrothermal method based on the reaction between SnCl2 and NaOH in ethanol/water. The ethanol amount is a crucial factor in controlling the size and morphology of the microsheets. Ethanol can accelerate the delamination of the SnO blocks to the microsheets, and the microsheets changed from a quasi square to an octodecahedral shape with the increase of the ethanol ratio. When the volume ratio of ethanol/water is 2:1, the microstructure of SnO presents a rose flower-like hierarchical architecture with a diameter of about 40 μm, which is regularly composed of numerous well-ordered thin microsheets with octodecahedral shape, and the microsheets were formed by countless nanoparticles. A possible growth mechanism of the architectures was proposed. Moreover, SnO2 nanospheres were synthesized by a similar experiment only without NaOH, which showed that NaOH was crucial to the formation of SnOx.

A label-free electrochemistry biosensor based flower-like 3-dimensional ZnO superstructures for detection of DNA arrays

A highly sensitive electrochemical DNA sensor was constructed by homogenously distributing Au nanoparticles (AuNPs) on a flower-like 3D ZnO superstructure–chitosan (CS) matrix.

Efficient adsorption and photocatalytic pceerformance of flower-like three-dimensional (3D) I-doped BiOClBr photocatalyst

Uniform well crystallized flower-like three-dimensional (3D) BiOClBr and I-doped BiOClBr microspheres with diameter of 1 μm were synthesized through a simple EG-assisted solvothermal method. The existence of I atoms in the BiOClBr compound could greatly enhance both adsorption and photocatalytic activity as compared with the BiOClBr and BiOX (Cl, Br, I) monomers. The highest catalytic performance of the flower-like 3D I-doped BiOClBr microspheres was preliminary deduced to be due to the much higher specific surface area, efficient sorption capacity as well as the unique interfacial structure. These factors may favor the absorption of light and separation of photogenerated charged carriers more effectively.

Facile synthesis of flower-like 3D ZnO superstructures via solution route

A novel flower-like 3D ZnO superstructure with high uniformity was fabricated on a large scale through a facile aqueous solution route at room temperature. The as-prepared ZnO superstructures with a diameter of about 3 μm are assembled by large amounts of interleaving nanosheets, which have a uniform thickness of about 15 nm and a well-crystalline structure with {100} planes as basal facets. The hierarchical microstructures, which were formed via a two-stage nucleation–growth process, highly depend on the concentration of NaOH and trisodium citrate dihydrate. The photoluminescence result indicates that the ZnO superstructures possess a relatively strong UV emission. The photodecomposition of methyl orange indicates that such ZnO superstructures possess excellent photocatalytic activity.

Synthesis of flower-like 3D ZnO microstructures and their size-dependent ethanol sensing properties

Flower-like 3D ZnO microstructures constructed from nanorods of different sizes were prepared by a microwave hydrothermal (MH) process in the presence of o-, m- and p-nitrobenzoic acid, respectively. Well-crystallized flower-like ZnO microstructures were obtained after 10 min MH treatment. The X-ray powder diffraction (XRD) test indicated that all the products were consistent with the hexagonal ZnO phase, and scanning electron microscopy (SEM) investigation revealed that the flower-like 3D ZnO microstructures were built with sword-like nanorods 60–100 nm in width and several micrometers in length. The formation mechanism of these flower-like 3D ZnO microstructures is discussed briefly. The gas sensitivity of the as-prepared ZnO microstructures to ethanol at different operation temperatures and concentrations was also studied. The results indicated that the gas sensitivity of the ZnO microstructures was influenced by the particle size and microcosmic configuration, the larger particles with crowded nanorods having higher gas sensitivity.

Synthesis and gas sensor properties of flower-like 3D ZnO microstructures

Flower-like ZnO 3D microstructures composed of nanorods have been successfully prepared via a facile hydrothermal method using p -nitrobenzoic acid as the structure-directing agent. The structures and morphologies of the final products have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscope (HRTEM). The possible mechanism for the synthesis of the flower-like ZnO microstructures has been proposed primarily. The gas sensitivity of the flower-like ZnO microstructures has been studied to a series of organic vapors at different operation temperatures and vapor concentrations. The results show that the flower-like ZnO microstructures composed of nanorods have good gas sensor properties to ethanol.

Facile additive-free solvothermal synthesis of cadmium sulfide flower-like three dimensional assemblies with unique optical properties and photocatalytic activity

Cadmium sulfide flower-like 3D assemblies were successfully prepared through a facile additive-free solvothermal process. It was found that the ethanol played an important role in the formation of the CdS assemblies. Based on the time-dependent experiments, a possible mechanism was proposed. In addition, the CdS assemblies exhibit unique optical properties and potential photocatalytic activity.

3차원 ZnO 나노구조체 가스센서

Due to the high surface-to-volume ratio, the 3-dimensional(3D) nanostructures of metal oxides are regarded as the best candidate materials for the chemical gas sensors. Here we have synthesised flower-like 3D zinc oxide nanostructures through a simple hydrothermal route. Specific surface area of the 3D zinc oxide nanostructures synthesised in different pH values from 9.0 to 12.0 were evaluated by using a BET analyzer and the results were compared with that of a zinc oxide thin film fabricated by rf sputtering. Using interdigitated electrodes, superior CO gas sensing properties of the 3D zinc oxide nanostructures on the ZnO thin film to those of the ZnO thin film were demonstrated.

Biomimetic Synthesis of Zinc Oxide 3D Architectures with Gelatin as Matrix

Peanut‐like and flower‐like zinc oxide 3D architectures were synthesized via a facile biomimetic process using gelatin as matrix. Techniques of XRD, SEM, HRTEM, FT‐IR, and UV‐vis absorption spectra were used to characterize the structure and property of the zinc oxide architectures. The experimental results show that the peanut‐like ZnO and flower‐like ZnO architectures can be obtained through changing the Zn2+ concentration or the aging time. FT‐IR spectra indicate that the Zn2+ is coupled with the C=O bond of the gelatin molecules through the electrostatic interaction. Based on the experimental process, the possible growth mechanism of the ZnO 3D architectures is proposed. UV‐vis absorption spectrum of the peanut‐like ZnO has a broad absorption band in the UV region, and the blue‐shifting of the band is observed.

Solvothermal synthesis and magnetic properties of 3D flower-like NiHPO3·H2O superstructures

A self-assembled three-dimensional (3D) flower-like NiHPO(3).H(2)O micro/nanocomposite structure has been successfully synthesized for the first time by a simple solvothermal method, employing Na(6)P(6)O(18) as the phosphor source without the assistance of any template or surfactant. The as-obtained product was characterized by X-ray powder diffraction, scanning electron microscopy and transmission electron microscopy. The formation mechanism was proposed based on the evolution of this morphology as a function of solvothermal time. Some factors influencing the morphology of the NiHPO(3).H(2)O flower-like micro/nanocomposite structures were systematically investigated. The magnetic measurements demonstrated that the flower-like 3D superstructures exhibit ferromagnetic property.