Organic Hybrid Structure Research Articles

Emerging Low Detection Limit of Optically Activated Gas Sensors Based on 2D and Hybrid Nanostructures.

Gas sensing is essential for detecting and measuring gas concentrations across various environments, with applications in environmental monitoring, industrial safety, and healthcare. The integration of two-dimensional (2D) materials, organic materials, and metal oxides has significantly advanced gas sensor technology, enhancing its sensitivity, selectivity, and response times at room temperature. This review examines the progress in optically activated gas sensors, with emphasis on 2D materials, metal oxides, and organic materials, due to limited studies on their use in optically activated gas sensors, in contrast to other traditional gas-sensing technologies. We detail the unique properties of these materials and their impact on improving the figures of merit (FoMs) of gas sensors. Transition metal dichalcogenides (TMDCs), with their high surface-to-volume ratio and tunable band gap, show exceptional performance in gas detection, especially when activated by UV light. Graphene-based sensors also demonstrate high sensitivity and low detection limits, making them suitable for various applications. Although organic materials and hybrid structures, such as metal-organic frameworks (MoFs) and conducting polymers, face challenges related to stability and sensitivity at room temperature, they hold potential for future advancements. Optically activated gas sensors incorporating metal oxides benefit from photoactive nanomaterials and UV irradiation, further enhancing their performance. This review highlights the potential of the advanced materials in developing the next generation of gas sensors, addressing current research gaps and paving the way for future innovations.

Resilient silica-based aerogels with organic and inorganic molecular hybrid structure prepared by a novel self-catalyzed gelling strategy for efficient heat insulation and CO2 adsorption

Silica aerogels have been attractive candidates for thermal insulation in many scenes, but they still suffer from high costs and especially brittle nature. In this work, a novel self-catalyzed gelling strategy was proposed to prepare resilient hybrid aerogels (HAs) with an organic–inorganic in-situ hybrid structure at the molecular level. Bis(trimethoxysilylpropy)amine is chosen as the single silicon source because it has alkalinity from the amine groups, high six functionality and molecular organic–inorganic hybrid nature, which help to achieve self-catalyzed gelling, high strength, and great resilience, respectively. For the as-prepared HAs, a 20 % fully recoverable strain, high Young’s modulus up to 10.40 MPa, high ultimate stress as high as 2.41 MPa and large ultimate deformation of 52 % are achieved together. Interestingly, HAs exhibit an improved modulus and strength after multiple compression, and this can increase the servicing safety in practical application. Benefiting from the synthetic effects of low density, high specific surface area and small pore size, the thermal conductivity of our aerogels is down to 18.8 mW·m−1·K−1 at ambient condition. Furthermore, the hydrophobic aerogels prepared through chlorotrimethylsilane modification also display a low thermal conductivity of 18.9 mW·m−1·K−1 at −50 °C and desirable mechanical properties at low temperatures. Unexpectedly, the rich amine groups and large specific surface area endow the fabricated aerogels with a remarkably high CO2 adsorption capacity up to 5.21 mmol/g at 273 K and excellent cyclic reusability. Considering these excellent functionalities, HAs have great prospects to serve as ideal thermal insulators, cold insulators and CO2 sorbents. The self-catalyzed gelling strategy provides an alternative route for the simple preparation of silica-based aerogels.

Silicon–Organic Hybrid Tunable Fabry–Perot Filter for Electro-Optic Modulation

Recently, electro-optic integrated photonic elements have attracted considerable interest owing to their widespread application in optical communication and signal processing. The strong electro-optical properties and the complementary metal–oxide semiconductor (CMOS) technology compatibility of silicon–organic hybrid structures makes them promising photonic platforms. This study investigated a novel implementation of a high-speed electrically tuned bandpass optical filter using finite-difference time-domain and eigenmode expansion numerical methods. The proposed device was based on a Fabry–Perot cavity and was realized via an electro-optic organic molecular glass filled slot waveguide with Bragg gratings. Furthermore, the calculation considered the plasma dispersion effect, free-carrier absorption in the silicon component of the slot waveguide for different applied voltages, and doping profiles corresponding to ion implantation. It is shown that the spatial distribution of charge carrier density formed by the surface states accumulation/depletion layers has a significant effect on the optical properties of the slot waveguide. Lithographic distortions in the geometry of the proposed structures during fabrication were also considered. Therefore, this paper presents an optical filter designed for fabrication using CMOS-compatible processes on silicon-on-insulator wafers. The filter produced a 3 nm tunable range for a 10 V bias voltage swing, a 0.3 nm full width at half maximum (FWHM) passband with a center at 1550 nm at zero bias voltage, and a 12.5 nm free spectral range with a 27 dB extinction ratio. The proposed device outperforms many narrow passband analogs in terms of sensitivity (tunability: 0.3 nm/V) and can be applied extensively in the fields of optical communications and photonic spectral signal processing.

The Role of Molecular Arrangement on the Strongly Coupled Exciton–Plasmon Polariton Dispersion in Metal–Organic Hybrid Structures

Metal–organic hybrid structures have been demonstrated to be a versatile platform to study primary aspects of light–matter interaction by means of emerging states comprising excitonic and plasmonic properties. Here we are studying the wave-vector-dependent photoexcitations in gold layers covered by molecular films of zinc phthalocyanine and its fluorinated derivatives (FnZnPc, with n = 0, 4, 8, 16). These layered metal–organic samples show up to four anticrossings in their dispersions correlating in energy with the respective degree of ZnPc fluorination. By means of complementary structural and theoretical data, we attribute the observed anticrossings to three main scenarios of surface plasmon coupling: (i) to aggregated α-phase regions within the FnZnPc layers at 1.75 and 1.85 eV, (ii) to a coexisting F16ZnPc β-polymorph at 1.51 eV, and (iii) to monomers, preferentially located at the metal interface, at 2.15 eV. Whereas energy and splitting of the monomer anticrossings depend on strength and average tilting of the molecular dipole moments, the aggregate-related anticrossings show a distinct variation with degree of fluorination. These observations can be consistently explained by a change in FnZnPc dipole density induced by an increased lattice spacing due to the larger molecular van der Waals radii upon fluorination. The reported results prove Au/FnZnPc bilayers a model system to demonstrate the high sensitivity of exciton–plasmon coupling on the molecular alignment at microscopic length scales.

Robust and flexible transparent protective film fabricated with an ambient-curable hybrid resin

An ambient-curable hybrid resin (ACHR) terminated with trimethoxysilane functional groups, synthesized through a simple ring-opening reaction between 3-glycidyloxypropyltrimethoxysilane (KH560) and 4,4′-methylenebis (cyclohexylamine) (PACM), was applied to the surface of a transparent organic polymer to produce a robust, flexible, and transparent protective hybrid film, moisture cured at room temperature. The structure, morphology, and optical, mechanical, and thermal properties of the obtained hybrid film were evaluated. The hybrid film allowed the transmittance of more than 87% of visible light (at 600 nm), maintaining almost the same high transparency as bare PET film. The unique flexible segments and rigid segments in the inorganic–organic hybrid structure of the film realized superior resistance to bending and scratching. The hybrid film-coated PET demonstrated excellent flexibility, with an extremely low bending radius, illustrated by wrapping around a 1-mm mandrel bar without cracking. In addition, the hybrid film exhibited superior pencil hardness (of 2H) and excellent wear durability, i.e., no scratching after being subjected to 200 abrasion cycles using #0000 steel wool under a 19.6 kPa load. The robust, flexible, and transparent protective film developed here, and its simple and efficient preparation method, should have extensive application prospects.

Efficient Charge Separation in Polypyrrole/GaN‐Nanorod‐Based Hybrid Heterojunctions for High‐Performance Self‐Powered UV Photodetection

The ozonosphere is infiltrated by UV‐A rays (λ = 320–400 nm) that reach the Earth's atmosphere, posing serious health problems such as premature aging and skin cancer. Owing to the importance of UV‐A ray detection, highly detective, novel, and high‐speed UV‐A photodetectors have recently attracted considerable attention. The integration of organic and inorganic hybrid structures yields highly attractive optoelectronic properties that make them attractive candidates for high‐performance self‐powered UV‐A photodetectors. Herein, the integration of conductive polypyrrole (Ppy) and GaN nanorods for high‐performance self‐powered UV‐A photodetectors is demonstrated. The device exhibits superior photoresponse properties such as detectivity, responsivity, and external quantum efficiency values as 5.0 × 1012 Jones, 102 A W−1, and 29.8 × 103%, respectively, at a power density of 1.32 mW cm−2 (λ = 382 nm) and zero bias, which are relatively higher than those of pristine GaN nanorods. Furthermore, the device exhibits good stability and reproducibility with fast rising (350 ms) and falling (410 ms) times. The high photoresponse is attributed to the large built‐in potential formed at the interface junction of the Ppy and the GaN nanorods. Furthermore, the mechanism behind the high photoresponse is investigated using an X‐ray photoelectron spectroscopy (XPS) analysis and energy band theory.

Injectable antibacterial antiinflammatory molecular hybrid hydrogel dressing for rapid MDRB-infected wound repair and therapy

Multidrug resistant-bacteria (MDRB) impaired wound repair and regeneration remains a critical challenge. The development of multifunctional bioactive dressing with excellent wound healing and MDRB treating ability could probably address this problem. Herein, we developed an injectable multifunctional poly (citrate-glycol-siloxane)-based (PCGS) molecular hybrid hydrogel dressing for treating MDRB infection and enhancing wound healing. The PCGS-based hydrogel dressing possesses good injectability, controlled mechanical properties, temperature-responsive sol–gel behavior, broad-spectrum antibacterial activity including against MDRB (>99.99%). This dressing demonstrated the excellent cytocompatibility and could significantly enhance the activity of fibroblasts proliferation and migration of endothelial cells. The in vivo studies showed that PCGS-based dressing could significantly inhibit the MDRB infection on wound and promote the wound healing and skin appendage construction through reinforcing the early angiogenesis and decreasing the infection-derived inflammation. Our study suggests that PCGS-based hydrogel dressing with inorganic–organic hybrid structure at molecular level would have the promising potential in treating MDRB-infected wound and skin repair.

A fluorescent and colorimetric probe of carbyne nanocrystals coated Au nanoparticles for selective and sensitive detection of ferrous ions

Dual-functional nanosensors for fluorescent and colorimetric detection of metal ions are generally shown in organic materials or complex organic-inorganic hybrid structures, and there are much few reports about dual-functional sensors made of pure and simple inorganic nanomaterials. Here, we report a fluorescent and colorimetric probe of the hybrid gold-carbyne nanocrystals structure for selective and sensitive detection of ferrous ions. We fabricate fluorescent carbyne nanocrystals (inorganic nanocrystals) capped with gold nanoparticles (CNCs@AuNPs) via a convenient one-step laser ablation in liquids. We demonstrate that, with involvement of ferrous ions, CNCs@AuNPs show fluorescence-quenching and color-producing properties, which make them be a double-channel platform for chemical and biomedical detection. With remarkably high selectivity towards ferrous ions over other metals, the fluorescent and colorimetric methods of the fabricated probe exhibit a detection limit of 14 μM and 1.2 μM, respectively. We also establish that the electron transferring plays an important role in facilitating these novel effects. These findings expand the applications of inorganic nanomaterials in chemical and biomedical sensing.

Flexible electrospun PVDF-BaTiO3 hybrid structure pressure sensor with enhanced efficiency.

Ceramic doped-polymer structures as organic and inorganic hybrid structures constitute a new area of advanced materials for flexible and stretchable sensors and actuators. Here, uniform ceramic-polymer composites of tetragonal BaTiO3 and polyvinylidene fluoride (PVDF) were prepared using solution casting to improve the pressure sensitivity. By introducing Ba–TiO3 nanoparticles to PVDF nanofibers, piezoelectricity and pressure sensitivity of hybrid nanofiber mats were significantly improved. In addition, we proposed a novel flexible and stretchable multilayered pressure sensor composed of electrospun nanocomposite fibers with high electrical sensitivity up to 6 mV N−1 compared to 1.88 mV N−1 for the pure PVDF sensors upon the application of cyclic loads at 2.5 Hz frequency and a constant load of 0.5 N. Indeed, this work provides a composition-dependent approach for the fabrication of nanostructures for pressure sensors in a wide variety of wearable devices and technologies.

Zero-dimensional ionic antimony halide inorganic–organic hybrid with strong greenish yellow emission

Here, we reported a new zero-dimensional ionic antimony halide inorganic–organic hybrid structure, H3SbBr6(L)6 (L = 2-(3-methyl-1H-imidazol-3-ium-1-yl)acetate).

Strongly emissive white-light-emitting silver iodide based inorganic-organic hybrid structures with comparable quantum efficiency to commercial phosphors.

A series of one-dimensional silver iodide based inorganic-organic hybrid structures with tunable white light emissions have been synthesized by Cu substitution. The white-light-emitting hybrid 1D-Ag2-xCuxI2L2 (x < 2, L = ligand) compounds exhibit extremely strong luminescence with internal quantum yield (IQY) as high as 95%, significantly higher than most of the previously reported direct white-light-emitting hybrid structures and comparable to the IQYs of commercial phosphors.

Synthesis, structure and photoluminescence properties of three copper(i) iodide based inorganic–organic hybrid structures with pyrazine derivatives

By using pyrazine derivatives, three different types of copper(i) iodide based inorganic–organic hybrid structures have been prepared.

In-situ growth of Ag on mussel-inspired polydopamine@poly(M-POSS) hybrid nanoparticles and their catalytic activity

Polyhedral oligomeric silsesquioxane (POSS) nanoparticles have gain much attention due to their organic and inorganic hybrid structure that combine with metal nanoparticles to improve their functional properties for utilize in potential application areas. In this study, we first time present a green route for in-situ growth of silver on the surface of POSS based support particles by using mussel inspired polydopamine (PDA) coating. The POSS based nanocomposite support were synthesized by free radical mechanism in one-step emulsion polymerization of methacryl(M)-POSS monomer. Smooth spherical shape in size range of 200 nm–400 nm poly(M-POSS) hybrid latex particles were covered by the functional amine and catechol groups of PDA. Silver layer were growth on PDA@poly(M-POSS) nanocomposite template. The novel multi-functional Ag@PDA@poly(M-POSS) nanocomposite particles were fully characterized by SEM, EDAX, XRD and FTIR analysis. The catalytic activity of the particles was checked by pseudo-first order kinetic reaction of nitrophenol compound, which is highly toxic for environment. The catalytic reaction performance was discussed by varying the catalyst amount and concentration of 4-nitrophenol. Compare to similar catalysts, results showed that Ag@PDA@poly(M-POSS) nanocomposite particles exhibited excellent catalytic activity for the rapid degradation of 4-NP.

Hydrothermal synthesis of gold nanoparticles and metal organic framework hybrid structure

We report a hydrothermal synthesis of a hybrid structure between gold nanoparticles and a metal organic framework, ZIF-8 (abbreviated as Au@ZIF-8). Au nanoparticles encapsulated in polyvinylpyrrolidone (PVP) was employed as seeds to grow the framework of ZIF-8. We controlled the position and concentrations of Au nanoparticles on ZIF-8 crystal by adjusting the volume of Au nanoparticles dissolved in DI water during the growth of ZIF-8. Morphology, structure, distribution of the hybrid structure were investigated by transmission microscope, powder xray diffraction, and diffuse reflectance UV-Vis spectroscopy. We tested out catalytic properties of Au@ZIF-8 through the reaction of 2-nitrophenol and NaBH4.

High‐Performance Yarn Supercapacitor Based on Metal–Inorganic–Organic Hybrid Electrode for Wearable Electronics

AbstractA flexible all‐solid‐state yarn supercapacitor (YSC) based on metal–inorganic–organic ternary hybrid structure is fabricated by assembling polypyrrole@manganese oxide nanosheets@stainless steel yarn (PMS) yarn electrode of core/sheath/sheath configuration. The PMS yarn electrode combines the advantages of each component and shows excellent electrochemical performance, mechanical flexibility, and flame retardance owing to its unique structure and synergistic effect. The as‐fabricated YSC exhibits a high areal specific capacitance of 181 mF cm−2, areal energy density of 16.1 µWh cm−2, and areal power density of 10.3 mW cm−2. Moreover, the device possesses desirable voltage/current scalability and outstanding mechanical stability, which maintains 95.8% capacitance retention after 1000 bending cycles. As a demonstration, four YSCs are connected in series and then charged for 10 s to drive a light‐emitting diode (LED) digital watch. The outstanding overall performance of the YSC indicates that it is an ideal flexible power source for safe wearable electronics.

Biomimetic, Flexible, and Self-Healable Printed Silver Electrode by Spontaneous Self-Layering Phenomenon of a Gelatin Scaffold

Organic-inorganic hybrid layer-by-layer (LBL) composite structures can not only increase the strength and ductility of materials but also well disperse nanomaterials for better-conducting pathways. Here, we discovered the self-assembly process of an organic and silver (Ag) LBL hybrid structure having excellent sustainability during the long-term bending cycle. During the assembly process, the organic and Ag hybrid structure can be self-assembled into a layered structure. Unlike other conventional LBL fabrication processes, we applied the hydrogel scaffold of a biological polymer, which can spontaneously phase separate into an LBL structure in a water/alcohol solvent system. This new hydrogel-based Ag LBL patterns can successfully be printed on a flexible polyimide film without nozzle-clogging problem. Although these Ag LBL patterns cracked during the bending cycle, carbonized organic compounds between the Ag layers help to self-heal within few minutes at a low temperature (<80 °C). On the basis of our new hydrogel-based Ag ink, we could fabricate a fully printed reliable microscale flexible heater. We expect that our self-layering phenomenon can expand to the broad research field of flexible electronics in the near future.

Metal–Organic Frameworks: Kinetic‐Controlled Formation of Bimetallic Metal–Organic Framework Hybrid Structures (Small 41/2017)

In article number 1702049, Wenhan Guo, Ruqiang Zou and co-workers develop a new strategy to synthesize metal–organic framework hybrid nanostructures by kinetic control. The growth kinetics of monometallic MOFs is revealed by in situ optical turbidity measurements, and accordingly bimetallic MOF nanoparticles with either solid-solution, core-shell or combined hybrid structures are purposively synthesized without the assistance of surfactants or modulators.

Formation of molybdate organic-hybrids and exfoliated molybdate nanosheets

Novel synthetic approaches for the effective construction of MoOx – organic hybrid structures and MoOx nanosheets (NSs) have been developed. A solvothermal (ST) treatment of molybdenum trioxide utilizing dodecylamine (DDA) as an intercalating agent leads to the formation of MoOx – DDA hybrid structures. Layer spacing as a function of organic molecule lengths can be controlled by changing the surfactants located between the nanosheets. Maintaining the integrity of the parent crystal, hexagonal-shaped molybdenum oxide NSs up to four micrometers in lateral size separate following sonication of the hybrid structures. Formation of MoOx–oleylamine (OAm) highly oriented nanosheets with plasmonic behavior were also achieved using a rapid ST treatment of molybdenum trioxide in the presence of OAm surfactant. The effects of time and temperature on the formation, morphology, and crystal structure of well-ordered nanosheets were explored. These synthesized hybrid nanostructures and NSs are expected to show great potential for a variety of applications including rechargeable batteries, catalysis, and nanodevices.

Inorganic Anions Regulate the Phase Transition in Two Organic Cation Salts Containing [(4-Nitroanilinium)(18-crown-6)]+ Supramolecules

Inorganic Anions Regulate the Phase Transition in Two Organic Cation Salts Containing [(4-Nitroanilinium)(18-crown-6)]+ Supramolecules

Preparation, characterization and evaluation of the catalytic power of an hybrid compound [H3PMo12O40-chitosan] for the azoic-colored solutions

Inorganic–organic hybrid structures have become novel alternatives for many applications as they combine the advantages of both systems. In this current study, a hybrid compound [H3PMo12O40-chitosan] was prepared using a wet impregnation method with different proportions (0-100 wt. %, considering the polymer as the main component). The chemical structure and the morphology of the synthesized compounds were studied using FT-IR and SEM. Their catalytic powers were evaluated for Naphtol Blue Black and Eriochrome Blue Black B. Experimental data revealed that the decolorization phenomenon depends on the structure of the dye it-self, the pH value, the initial dye concentration, the time contact, the oxidant dose and the temperature. Kinetic data, well described using the first order model, allowed us to establish the thermodynamic parameters. The calculated low values of Ea (7.48 and 8.14 KJ. mol-1) proved the efficiency of the prepared catalyst. Eriochrome Blue Black B could be decomposed more rapidly than Naphtol Blue Black. As example, after a period of 30 min of reaction, the target removals were, respectively, 70% and 15% for mono and bi-azoic dyes. The reuse of the catalyst is carried out and it was found to be recyclable more than three consecutives cycles.