Organic-inorganic Hybrid Nanostructures Research Articles

Conjugated polymer P3HT-Au hybrid nanostructures for enhancing photocatalytic activity.

Metal-semiconductor nanostructures have been the subject of great interest, mainly due to their interesting optical properties and their potential applications in light harvesting, photocatalysis and photovoltaic devices. Here, we have designed raspberry type organic-inorganic hybrid nanostructures of the poly-3-hexylthiophene (P3HT)-Au nanoparticle (NP) composite by a simple solution based synthetic method. The electronic interaction of semiconducting P3HT polymer nanoparticles with Au nanoparticles exhibits a bathochromic shift of absorption bands and significant photoluminescence quenching of P3HT nanoparticles in this organic-inorganic hybrid system. The photocatalytic activity of this raspberry type hybrid nanostructure is demonstrated under the visible light irradiation and the degradation efficiency is found to be 90.6%. Such organic-inorganic hybrid nanostructures made of a semiconducting polymer and plasmonic nanoparticles could pave the way for designing new optical based materials for applications in photocatalytic and light harvesting systems.

Ion exchanged LaF3:Tb3+ based inorganic–organic hybrid nanostructures and their strong luminescence

Tb3+ doped LaF3 (LaF3:Tb3+) is an important green light emitting material, but the low optical absorption cross-section of Tb3+ ions strongly limits its luminescence properties. In this work, we used an ion exchange method to prepare LaF3:Tb3+ based inorganic–organic hybrid nanostructures, which exhibited strong luminescence as a result of luminescence sensitization, an energy transfer process from the organic ligands to the Tb3+ ions. The undoped LaF3 nanoparticles were first synthesized by a simple hydrothermal method, and Tb3+ ions were then ion exchanged into these LaF3 nanoparticles to form the LaF3:Tb3+ nanoparticles, which were then used to prepare the inorganic–organic hybrid nanostructures with benzoic acid. The LaF3:Tb3+ based inorganic–organic hybrid nanostructures had an emission intensity more than 44 times stronger than the as-prepared LaF3:Tb3+ nanoparticles. Dependence of their luminescence on the Tb3+ doping concentration and amount of organic ligands was studied in detail.

Nickel-functionalized reduced graphene oxide with polyaniline for non-enzymatic glucose sensing

We have developed a new class of organic–inorganic hybrid nanostructures based on the use of reduced graphene oxide (rGO), polyaniline, and a nickel metal nanostructure. It was applied to efficient non-enzymatic sensing of glucose based on its electrocatalytic oxidation. Scanning electron microscopy and energy-dispersive X-Ray were employed to characterize the material. It is shown that the doped polyaniline plays an important role in the formation of the hybrid nanostructures. Improved analytical performance is found when the hybrid nanostructures were placed on a glassy carbon electrode and used for non-enzymatic sensing of glucose at a typical working potential of +450 mV and a pH value of 13. Features include a fast response (~2 s), high sensitivity (6,050 μA mM−1 cm−2), a linear range from 0.1 μM to 1.0 mM, and a low detection limit (0.08 μM). The response to glucose follows a Michaelis-Menten kinetic behavior, and the KM value was determined to be 0.241 μM. Reproducibility and specificity are acceptable. Fructose and maltose do not interfere significantly. Importantly, the methodology was validated and evaluated for the analysis of 15 spiked human serum specimens, receiving in a good accordance with the results obtained by the non-enzymatic glucose sensing and the commercialized personal glucose meter.

In situ formation of organic-inorganic hybrid nanostructures for photovoltaic applications.

The performance of hybrid (organic-inorganic) photovoltaic devices is critically dependent on the thin film morphology. This work studies the film formation process using the in situ thermal decomposition of a soluble precursor to form a well-distributed network of CdS nanoparticles within a poly(3-hexylthiophene) (P3HT) polymer matrix. Resonant Raman spectroscopy is used to probe the formation of the inorganic nanoparticles and the corresponding changes in the molecular order of the polymer. We find that the CdS precursor decomposes rapidly upon heating to 160 °C, but that this has a disruptive effect on the P3HT. The extent of this disruption can be controlled by adjusting the annealing temperature, and nanowire aggregates of P3HT are found to have increased susceptibility. Atomic force microscopy reveals that at high temperatures (>200 °C), cracks form in the film, resulting in a 'plateau'-like microstructure. In order to retain the preferable 'granular' microstructure and to control the molecular disruption, low decomposition temperatures are needed. This work identifies a particular problem for optimising the hybrid thin film morphology and shows how it can be partially overcome.

A non-aqueous procedure to synthesize amino group bearing nanostructured organic-inorganic hybrid materials.

Amino-functionalized organic-inorganic hybrid materials with a narrow distributed nanostructure of 2-4 nm in size were obtained by means of a template-free and non-aqueous procedure. Simultaneous twin polymerization of novel amino group containing twin monomers with 2,2'-spirobi[4H-1,3,2-benzodioxasiline] has been applied for this purpose. The amino groups of the organic-inorganic hybrid material are useful for post derivatization.

Singlets and triplets in hybrid nanodevices

An organic material thin layer can be used to resonantly absorb light and nonradiatively transfer excitation to an adjacent inorganic quantum well the optical nonlinearities of which can in this way be turned on more efficiently than by direct optical pumping. We theoretically consider this process in a hybrid structure based on crystalline tetracene in which the singlet exciton energy is close to twice the one of a triplet exciton and thermally activated singlet exciton fission into two triplets can be efficient. We investigate how the temperature dependence of the singlet exciton diffusion length affects the functional properties of such hybrid organic-inorganic nanostructures based on tetracene. We show how temperature activated fission opens a new possibility to turn on and off the indirect pumping due to energy transfer from the organic into the inorganic subsystem.

Synthesis and luminescence of Y2O3:Eu3+ inorganic–organic hybrid nanostructures with thenoyltrifluoroacetone

Cubic Y2O3:Eu3+ nanoparticles with a size about 32nm were synthesized using a facile hydrothermal method followed by an annealing process. As expected, the Y2O3:Eu3+ nanoparticles had a broad Eu–O excitation band ranging from 200nm to 285nm peaking at about 260nm. The Y2O3:Eu3+ nanoparticles were then used to fabricate the inorganic–organic hybrid nanostructures with thenoyltrifluoroacetone (TTA). The Y2O3:Eu3+–TTA hybrid nanostructures exhibited a new strong excitation band ranging from 280nm to 390nm peaking at about 368nm. This new excitation band was attributed to the energy transfer mechanism of the Y2O3:Eu3+–TTA hybrid system. It is interesting to note that this energy transfer mechanism had a close interaction with the Eu–O excitation of Y2O3:Eu3+ nanoparticles. The phase structures, chemical bonding information, microstructural characteristics and luminescence properties were investigated.

Surface-Functionalized Particles: From their Design and Synthesis to Materials Science and Bio-Applications

The purpose of this highlight is to demonstrate the importance of the surface functionalization of nanoparticles toward the design of high-tech (nano)materials. These (nano)materials are “nano-tools” for the already established interdisciplinary research fields of nanoscience and nanotechnology, which find an enormous variety of applications in different areas. In many cases, the particle-forming material, shape, and size determine the applicability of the desired nanoparticle. Nevertheless, in most of the cases other parameters must also be accurately adjusted to transform those nano-objects into functional nanoparticles, such as dispersibility, stability, reactivity, ability to recognize (or to be recognized by) other systems, and the interaction between these parameters and a matrix or dispersing medium. Most of these parameters are mainly depending on the surface characteristics of the nanoparticles. Thus, this highlight focuses not only on the importance of the surface functionalization of the nanoparticles to render them applicable, but also on the different strategies to design and obtain surface-functionalized nanoparticles (SF-NPs) and on their successful exploitation in materials science, formulation of organic–inorganic hybrid nanostructures and bio-applications.

Nanocrystalline p-hydroxyacetanilide (paracetamol) and gold core–shell structure as a model drug deliverable organic–inorganic hybrid nanostructure

We report on the generation of core-shell nanoparticles (NPs) having an organic nanocrystal (NC) core coated with an inorganic metallic shell, being dispersed in aqueous medium. First, NCs of p-hydroxyacetanilide (pHA)--known also as paracetamol--were generated in an aqueous medium. Transmission electron microscopy (TEM) and powder X-ray diffraction (XRD) evidenced the formation of pHA NCs and of their crystalline nature. The NCs were then coated with Au to form pHA@Au core-shell NPs, where the thickness of the Au shell was on the order of nanometers. The formation of Au nanoshell--surrounding pHA NC--was confirmed from its surface plasmon resonance (SPR) band in the UV/Vis spectrum and by TEM measurements. Further, on treatment of the core-shell particles with a solution comprising NaCl and HCl (pH < 3), the Au shell could be dissolved, subsequently releasing pHA molecules. The dissolution of Au shell was marked by a gradual diminishing of its SPR band, while the release of pHA molecules in the solution was confirmed from TEM and FTIR studies. The findings suggest that the core-shell NP could be hypothesized to be a model for encapsulating drug molecules, in their crystalline forms, for slow as well as targeted release.

Fabrication of a novel nano-composite carbon paste sensor based on silica-nanospheres functionalized with isatin thiosemicarbazone for potentiometric monitoring of Cu2+ ions in real samples

The present paper describes the fabrication of a novel nano-structured organic–inorganic hybrid potentiometric sensor based on silica nanospheres functionalized with isatin thiosemicarbazone (ITC@APTES@SiO2) as a neutral carrier for the rapid and sensitive determination of Cu(II) ions in real samples. Furthermore, multi-walled carbon nanotubes (MWCNTs) and room temperature ionic liquid (RTIL) (1-n-butyl-3-methylimidazolium tetrafluoroborate) have been used in the composition of carbon paste to improve its conductivity and transduction of the chemical signal to the electrical signal. The sensing material (ITC@APTES@SiO2) was synthesized by immobilizing isatin thiosemicarbazone (ITC) onto aminopropyl functionalized silica nanospheres (APTES@SiO2), and characterized by Fourier transform infrared (FT-IR) spectroscopy, solid-state 13C CPMAS and 29Si CPMAS NMR spectroscopy, Brunauer–Emmett–Teller (BET) surface area analysis, X-ray diffraction (XRD), transmission electron microscopy (TEM) and elemental analysis. The nano-composite sensor exhibits a stable potential response to Cu(II) ions with a Nernstian slope of 29.3 ± 0.28 mV decade−1 over a wide linear dynamic concentration range of 1.0 × 10−7 to 1.0 × 10−1 M with a detection limit of 5.01 × 10−8 M. Furthermore, it demonstrates a fast response time of about 5 s, and can be used for at least 3 months without any significant variance in the potential. The potential response of the proposed sensor was found to be independent of pH in the range of 2.5–7. In addition, the electrode was found to be highly selective for Cu(II) ions with respect to alkali, alkaline earth, transition and heavy metal ions. The response mechanism of the nano-composite sensor was also investigated using UV-vis spectrophotometric analysis and the AC impedance technique. The practical utility of the developed sensor has also been reported for diverse real samples.

Accommodating Curvature in a Highly Ordered Functionalized Metal Oxide Nanofiber: Synthesis, Characterization, and Multiscale Modeling of Layered Nanosheets

A key element in the rational design of hybrid organic–inorganic nanostructures is control of surfactant packing and adsorption onto the inorganic phase in crystal growth and assembly. In layered single crystal nanofibers and bilayered two-dimensional (2D) nanosheets of vanadium oxide, we show how the chemisorption of preferred densities of surfactant molecules can direct the formation of ordered, curved layers. The atom-scale features of the structures are described using molecular dynamics simulations that quantify surfactant packing effects and confirm the preference for a density of 5 dodecanethiol molecules per 8 vanadium attachment sites in the synthesized structures. This assembly maintains a remarkably well ordered interlayer spacing, even when curved. The assemblies of interdigitated organic bilayers on V2O5 are shown to be sufficiently flexible to tolerate curvature while maintaining a constant interlayer distance without rupture, delamination, or cleavage. The accommodation of curvature and inv...

Functionalized nanoporous TiO2 fibers on quartz crystal microbalance platform for formaldehyde sensor

Abstract This paper describes the detection of formaldehyde through analyses of the resonance frequency signal from quartz crystal microbalance (QCM) sensors coated with a novel organic–inorganic hybrid sensing coating. Nanoporous titanium dioxide (TiO2) fibers with high Brunauer–Emmett–Teller (BET) surface area (68.72 m2/g) were fabricated by electrospinning a sol–gel titanium tetraisopropoxide (TIP)/polystyrene (PS) composite solution and following calcination process. Ethylene glycol (EG) dispersed TiO2 nanofibers were drop casted onto the electrode of QCM, followed by the functionalization of the sensing polyethyleneimine (PEI) on the fibers. The nanoporous TiO2 fibers covered with PEI layers worked as a highly sensitive sensing interface to provide output signal for weight changes during exposure to formaldehyde vapor. The developed formaldehyde-selective sensors exhibited rapid response and low detection limit (1 ppm) at room temperature. This is because the high specific surface area of the electrospun nanoporous TiO2 fibers and efficient nucleophilic addition reaction between formaldehyde molecules and primary amine groups of PEI. Our new synthetic methodology promises to be a powerful approach to fabricating hybrid organic–inorganic nanostructures on QCM for gas sensing and chemical analysis.

ChemInform Abstract: The Chemistry of Organoimido Derivatives of Polyoxometalates

AbstractReview: 175 refs.

Fabrication of a new type of organic-inorganic hybrid superlattice films combined with titanium oxide and polydiacetylene

We fabricated a new organic-inorganic hybrid superlattice film using molecular layer deposition [MLD] combined with atomic layer deposition [ALD]. In the molecular layer deposition process, polydiacetylene [PDA] layers were grown by repeated sequential adsorption of titanium tetrachloride and 2,4-hexadiyne-1,6-diol with ultraviolet polymerization under a substrate temperature of 100°C. Titanium oxide [TiO2] inorganic layers were deposited at the same temperatures with alternating surface-saturating reactions of titanium tetrachloride and water. Ellipsometry analysis showed a self-limiting surface reaction process and linear growth of the nanohybrid films. The transmission electron microscopy analysis of the titanium oxide cross-linked polydiacetylene [TiOPDA]-TiO2 thin films confirmed the MLD growth rate and showed that the films are amorphous superlattices. Composition and polymerization of the films were confirmed by infrared spectroscopy. The TiOPDA-TiO2 nanohybrid superlattice films exhibited good thermal and mechanical stabilities.PACS: 81.07.Pr, organic-inorganic hybrid nanostructures; 82.35.-x, polymerization; 81.15.-z, film deposition; 81.15.Gh, chemical vapor deposition (including plasma enhanced CVD, MOCVD, ALD, etc.).

Temporally and spatially controlled silicification for self-generating polymer@silica hybrid nanotube on substrates with tunable film nanostructure

This paper describes a novel approach to templated silicification that could directly generate a tubular structure with a polymer@silica hybrid wall. We developed a new process for the crystallization-driven self-assembled formation of a linear polyethyleneimine (LPEI) template on a substrate surface, which involves the key step of alkali-quenching of the complete deprotonation reaction of the adsorbed, protonated LPEI fraction on the substrate at room temperature. This alkali-induced LPEI template allowed the temporally and spatially controlled silicification reaction, leading to the self-generation of a tubular structure with a 3 nm LPEI@silica hybrid wall. The elemental nanotubes were organized hierarchically into two-dimensional mats and the mats were further vertically arrayed into a thin film. Such nanotube-based hybrid films could be formed reproducibly either on glass or on plastic. The surface morphology and nanostructure of the film could be tunable by simply adjusting solution conditions for LPEI self-assembly or by using substrates with controlled surface chemistry. After introducing hydrophobic residues on the film, the hierarchical nanotube surface showed the best repellency toward inkjet ink compared to the nanoribbon- and nanowire-based superhydrophobic surface. We also expanded this templated silicification to synthesize hybrid nanotube powders in solution. Both Brunauer–Emmett–Teller (BET) and transmission electron microscopy (TEM) studies supported direct formation of an approximately 3 nm hollow structure. Thin film X-ray diffraction measurements (XRD), X-ray photoelectron spectroscopy (XPS) and thermogravimetry analysis (TGA) characterizations indicated the hybrid nature of the LPEI@silica wall. This new approach advanced on the conventional methods of using an organic template to direct inorganic materials, and is expected to be generally applicable to directly generate other organic–inorganic hybrid nanostructures.

The chemistry of organoimido derivatives of polyoxometalates

The chemistry of organoimido derivatives of polyoxometalates (POMs) has received increasing interest. In recent decades, a great development of the synthetic chemistry of organoimido derivatives of POMs using different imido-releasing reagents has taken place, particularly the novel DCC-dehydrating protocol to prepare organoimido derivatives of POMs was developed recently by us and co-workers. Organoimido substituted POMs as valuable building blocks can construct novel nanostructured organic-inorganic hybrid molecular materials in well-developed common organic synthesis methods, such as Pd-catalyzed carbon-carbon coupling and esterification. Therefore, the reactive chemistry of organoimido derivatives of POMs stands for the fascinating future of the chemistry of organoimido derivatives of POMs.

Enhanced electrocatalytic activity of a new carbon nanocomposite electrode based on organic–inorganic hybrid nanostructures

Organic–inorganic hybrid nanostructures are successfully synthesized by incorporating 3,3′,5,5′-tetramethylbenzidine (TMB) and palladium chloride (PdCl 2) at room temperature. The general morphology of the product was characterized by transmission electron microscopy (TEM) which displayed Pd distributed in the TMB matrix. A novel nanocomposite electrode was constructed by incorporation of the as-prepared product into carbon ionic liquid electrode (CILE). After reduction of Pd(II) to Pd(0) during a negative reduction pulse; the electrocatalytic properties of the composite electrode were investigated towards oxygen reduction, hydrogen evolution and hydrazine oxidation all of which revealed strong electrocatalytic activities at room temperature.

Efficient dual mode multicolor luminescence in a lanthanide doped hybrid nanostructure: amultifunctional material

The present work deals with inorganic–organic hybrid nanostructures capable of producingintense visible emission via upconversion (UC), downconversion (DC), and energy transfer(ET) processes which show the potential of the material as a luminescent solar collector(LSC), particularly to improve the efficiency of silicon solar cells. To achieve this,Gd2O3:Yb3 + /Er3 + phosphor (averageparticle size ∼ 35 nm) and a Eu(DBM)3Phen organic complex have been synthesized separately and then the hybrid structure has been developedusing a simple mixing procedure. Intense UC emission (in the red, green, and blue regions) due toEr3 + is observed on near infrared (976 nm) excitation which shows colortunability with input pump power. In contrast, intense red emission ofEu3 + is observed on ultaviolet (UV) (355 nm) excitation. The feasibility of energy transfer fromEr3 + ionsto Eu3 + ions has also been noted. These excellent optical properties are retained even if theparticles of the hybrid nanostructure are dispersed in liquid medium, which also makes itsuitable for security ink purposes.

Novel hybrid organic/inorganic 2D quasiperiodic PC: from diffraction pattern to vertical light extraction

Recently, important efforts have been dedicated to the realization of a fascinating class of new photonic materials or metamaterials, known as photonic quasicrystals (PQCs), in which the lack of the translational symmetry is compensated by rotational symmetries not achievable by the conventional periodic crystals. As ever, more advanced functionality is demanded and one strategy is the introduction of non-linear and/or active functionality in photonic materials. In this view, core/shell nanorods (NRs) are a promising active material for light-emitting applications. In this article a two-dimensional (2D) hybrid a 2D octagonal PQC which consists of air rods in an organic/inorganic nanocomposite is proposed and experimentally demonstrated. The nanocomposite was prepared by incorporating CdSe/CdS core/shell NRs into a polymer matrix. The PQC was realized by electron beam lithography (EBL) technique. Scanning electron microscopy, far field diffraction and spectra measurements are used to characterize the experimental structure. The vertical extraction of the light, by the coupling of the modes guided by the PQC slab to the free radiation via Bragg scattering, consists of a narrow red emissions band at 690 nm with a full width at half-maximum (FWHM) of 21.5 nm. The original characteristics of hybrid materials based on polymers and colloidal NRs, able to combine the unique optical properties of the inorganic moiety with the processability of the host matrix, are extremely appealing in view of their technological impact on the development of new high performing optical devices such as organic light-emitting diodes, ultra-low threshold lasers, and non-linear devices.PACS: 81.07.Pr Organic-inorganic hybrid nanostructures, 81.16.-c Methods of nanofabrication and processing, 42.70.Qs Photonic band-gap materials.

On the interpretation of the Raman spectra of Maya Blue: a review on the literature data

AbstractThe Raman spectroscopy of Maya Blue (MB), a nanostructured organic–inorganic hybrid material, has received considerable attention. A re‐evaluation of the Raman literature data for indigo dye, genuine MB samples and model specimens obtained by the binding of indigo to phyllosilicate clays, such as palygorskite and sepiolite, using chemometric analysis of normalised spectra is reported. Available data present features in support of the following ideas: (1) dehydroindigo accompanies indigo in MB; (2) different topological isomers, i.e. dye molecules attached to different coordinative sites of the palygorskite framework, are involved in MB; and (3) different procedures were probably used for preparing MB in ancient Mesoamerican civilisations. Copyright © 2010 John Wiley &amp; Sons, Ltd.