Oxide Hybrid Materials Research Articles

Simultaneous synthesis of sulfonated reduced graphene oxide@graphene oxide hybrid material for efficient electrochemical sensing of silver ions in drinking water

One of the most important concerns around the world nowadays is the drinking water quality. Silver ions (Ag+) are one of the heavy metal ions that can seriously degrade the water quality and therefore, the human health. Hence, the World Health Organization (WHO) fixed the maximum acceptable concentration of these ions in drinking water at approximately 0.93 µM. Thus, the development of cost-effective and efficient techniques and tools that can help to quantify Ag+ ions in drinking water is of great importance. Herein, we used a new, simple, eco-friendly and low-cost synthesis route to synthesize a sustainable hybrid carbon material, namely sulfonated reduced graphene oxide@graphene oxide (S-rGO@GO) that was utilized as electrode material for Ag+ ions electroanalysis in drinking water. The successful synthesis of S-rGO@GO was evidenced by XRD, Raman spectroscopy, XPS, FE-SEM and EDX. The electrochemical characterization of S-rGO@GO revealed its good affinities towards Ag+ and its good electron transport abilities. The sensor prepared from S-rGO@GO (S-rGO@GO/GCE) showed good repeatability and reproducibility. S-rGO@GO/GCE optimization revealed that its best performance is achieved when 5 µL of 1 mg/mL of S-rGO@GO suspension in ultrapure water is used for its fabrication and when the electrodeposition (Ag+ to Ag0) is carried out at -0.1 V vs. SCE for 200 s. The calibration of S-rGO@GO/GCE exhibited a linear relationship in the concentration range of 0.2 to 1.4 µM, with a sensitivity of (0.605 ± 0.015) µA/µM; the statistic LOD was found to be 0.0007 µM. Furthermore, S-rGO@GO/GCE has shown a great potential for real samples analysis.

Multi-compartmentalized electrochemical sensing platforms for monitoring cascade enzymatic reactions

Designing an electrochemical biosensor with the required features is a complex process involving multiple factors. For instance, nanocomposite materials used ensure the adaptation of the sensor to specific parameters on demand. But beyond making more versatile sensors, these materials likely offer excellent sensing platforms to mimic biological processes (e.g. cell communication) on the electrode surface. For this, developed methods are needed to integrate non-conductive nanoreactors for molecular communication into a biocompatible matrix on electrode surfaces with the request of spatially separated and controlled enzyme localization. Here, we present a novel reduced graphene oxide hybrid material to immobilize polymeric nanoreactors supported by an alginate network as a matrix on the electrode surface. The possibility of introducing cascade reactions in an electrochemical biosensor has the advantage of broadening the target substrates as well as their selectivity using enzymes in different nanocompartments (=compartmentalization). The polymeric vesicles allow the loading of enzymes or artificial enzymes, offering active center retention and long-term enzyme stability. Firstly, the inclusion of spatially separated polymeric active nanocompartments into the matrix on the electrode surface is used to monitor a simple enzyme reaction. However, the study’s accomplishment lies in its successful ability to monitor an enzyme cascade reaction, one producing and the other consuming hydrogen peroxide, hosting natural and artificial enzymes. This proof-of-concept generates an important contribution to the design of analytical platforms capable of detecting complex environments or even monitoring communication between cell-like structures, extremely useful for fields such as synthetic biology, biomimetics and advanced biosensors.

Propranolol chiral analysis using voltammetric sensor based on triterpenoid-graphene oxide hybrid material

Enantioselective sensors are potentially in demand at all stages of the production, storage and use of drugs, including identifying impurities of undesirable isomers and improving stereoselective synthesis methods. A key aspect for enantioselective sensors design is the development of appropriate molecular architectures that make it possible to create recognition sites with different affinities for enantiomers. This experimental work proposes a new chiral sensor based on glassy carbon electrode (GCE) modified by graphene oxide (GO) covalent functionalized with pentacyclic triterpenoid betulonic acid (BetA) for voltammetric recognition and determination of propranolol (Prop) enantiomers. Characterization of the materials was carried out using FTIR spectroscopy, scanning electron microscopy and cyclic voltammetry. Differential pulse voltammetry was used for Prop enantiomers recognition and quantification. The potential difference reached 30 mV along with enanitoselectivity coefficient ipS/ipR equal to 1.30. The calculated binding energy for S-Prop/GO-BetA complex is higher by 4.801 kcal moll−1 compared to R-Prop/GO-BetA indicating a more favorable mutual arrangement of molecules. The linear determination range was established as 5.0 × 10-6 ∼ 1.0 × 10-4 mol·L-1 and 1.0 × 10-4 ∼ 4.0 × 10-4 mol·L-1 for both enantiomers. The detection limits were determined to be 3.9⋅10-7 mol·L-1 and 5.0⋅10-7 mol·L-1 for S-Prop and R-Prop, respectively. The standard spike-recovery tests were carried out in human biological fluids with recoveries 97.3 % − 106.9 % for both enantiomers. The proposed sensor was used to determine the ratio of Prop enantiomers in mixture by regression analysis with projection to latent structures (PLS). The purpose was to build a PLS-model based on a calibration set containing a known number of Prop enantiomers and recognize a test set prepared independently. All samples of test set are correctly identified and the RSD did not exceed 8.7 %. GCE modified by covalent functionalized GO with BetA showed better stability compared with noncovalent functionalization in terms of electrode degradation.

Graphdiyne/metal oxide hybrid materials for efficient energy and environmental catalysis.

Graphdiyne (GDY)-based materials, owing to their unique structure and tunable electronic properties, exhibit great potential in the fields of catalysis, energy, environmental science, and beyond. In particular, GDY/metal oxide hybrid materials (GDY/MOs) have attracted extensive attention in energy and environmental catalysis. The interaction between GDY and metal oxides can increase the number of intrinsic active sites, facilitate charge transfer, and regulate the adsorption and desorption of intermediate species. In this review, we summarize the structure, synthesis, advanced characterization, small molecule activation mechanism and applications of GDY/MOs in energy conversion and environmental remediation. The intrinsic structure-activity relationship and corresponding reaction mechanism are highlighted. In particular, the activation mechanisms of reactant molecules (H2O, O2, N2, etc.) on GDY/MOs are systemically discussed. Finally, we outline some new perspectives of opportunities and challenges in developing GDY/MOs for efficient energy and environmental catalysis.

Nitrogen, sulfur coordinated metal complex and reduced graphene oxide hybrid materials as counter electrodes for application in dye-sensitized solar cells

Graphene, as one of the carbon-based materials, is considered to be a potential replacement for platinum and has been widely used as a counter electrode in dye-sensitized solar cells to achieve low-cost and high electrocatalytic materials. In this work, we synthesized a nitrogen-sulfur-coordinated iron complex as a source of heteroatoms, and prepared iron-nitrogen-sulfur co-doped reduced graphene oxide (FeNS-rGO) composite material by mixing with different mass ratios of graphene oxide (GO) and thermal annealing under nitrogen at 400 °C. The sintered GO was transformed into rGO, which increased the conductivity of materials, while the doping of nitrogen and sulfur atoms enhanced the carrier mobility and conductivity of the material. The distribution of Fe on graphene also improved the catalytic performance of material. FeNS-rGO (5:1), used as the CE in DSSC, showed superior reduction catalytic activity for I−/I3− compared to platinum and demonstrated an excellent power conversion efficiency of 8.17 %, which outperformed platinum. This proves that the graphene composite material doped with iron, nitrogen, and sulfur has excellent performance and can be used as a substitute for platinum.

Reforming of graphite oxide from agro-waste by incorporating nanosilica for the remediation of nitrate and phosphate anions from wastewater

Graphite oxide obtained from the oxidation of sawdust with (0.5 wt%) was immobilized into silica to improve the effectiveness of the silica phase toward depollution. The functional interaction profiles were assessed using XRD and SEM performances. The excess loading of graphite oxide percent encouraged the aggregation of incorporated silica molecules, forming the so-called “colonies”. Such colonies caused marked exfoliation of graphite oxide layers in the as-designed silica @graphite oxide hybrid materials and considerable coalescence of graphite oxide in a silica matrix. The as-designed silica @(0.01) graphite oxide nanocomposites showed pronounced sorption competencies for PO4-3 (95 %), not the same for NO3– (72 %). Such depollution behavior is governed by the interaction profiles including the incorporated graphite oxide and “silica colonies”. The fitness of the kinetic models was ranked as pseudo-first order. The values of ΔHo = 0.824 and 3.58, So = 0.109 and 0.116, and Go = –33.45 to −36.7 kJ/mole for phosphate and nitrate, respectively. The estimated data point to endothermic, spontaneous adsorption in nature.

Synthesis and characterization of titanium and aluminum complexes of 2-methoxybenzyl alcoholate and their use in base-catalyzed twin polymerization

The synthesis and characterization of twin monomers [Ti(OCH2-2-MeO-C6H4)4(HOCH2-2-MeO-C6H4)]2 (3) and [Al(OCH2-2-MeO-C6H4)3]4 (5) by reacting HOCH2-2-MeO-C6H4 (1) with Ti(OiPr)4 (2), or 1 with AlMe3 (4) is discussed. Single crystal X-ray structure analysis of 3 shows a dimeric structure with two alkoxide ligands bridging the titanium ions, while the others are terminal bonded. The respective phenolic resin / metal oxide hybrid materials HM_Ti and HM_Al were obtained in moderate (HM_Ti) to excellent (HM_Al) yields using typical base-catalyzed twin polymerization conditions (230 °C, 2 h). Nuclear magnetic resonance and infrared spectroscopy as well as scanning electron microscopy and scanning transmission electron microscopy combined with energ-dispersive X-ray spectroscopy proved the formation of inorganic–organic hybrid materials consisting of resin and MxOy materials (HM_Ti, TiO2; HM_Al, Al2O3) containing interpenetrating phase nano-domains with sizes of < 5 nm, as is charcteristic for twin polymerization processes. Oxidation of HM_Ti and HM_Al yielded the respective oxide materials Ox_Ti (TiO2) and Ox_Al (Al2O3), which possess low surface areas of ABET = 53 m2/g and 76 m2/g, respectively.

Revealing the key role of MnSiO3 in boosting the lithium storage performance of bamboo-derived anode materials

Carbon/manganese oxide hybrid materials, as potential candidates for lithium-ion battery anode materials, have attracted extensive attention due to their abundant resources and simple preparation. However, poor rate performance, weak cycle stability, and relatively high cost still limit their further development as commercial materials for next-generation Li-ion batteries. Herein, a novel carbon/manganese oxide hybrid material was fabricated from low-cost carbonized bamboo leaves and manganese nitrate for the lithium-ion battery anode. Interestingly, an additional MnSiO3 component found in this hybrid material is able to increase the material's intrinsic conductivity for improving the charge transfer as well as to enhance the Li+ diffusion ability for accelerating the reaction kinetics. Thus, the rate capability and cycle performance of the prepared hybrid material with additional MnSiO3 have been significantly improved by 18.4 and 52.6 %, respectively, compared to hybrid material without the MnSiO3 component. Moreover, the cycle performance of this hybrid material is also superior to that of many similar carbon/silicate and carbon/manganese oxide hybrid materials. Thanks to the excellent electrochemical performance, our hybrid material has also been successfully fabricated into a lithium-ion full battery, which displays considerable energy storage performance and good practical application ability.

Plasmonic nanoparticles doped metal oxide hybrid materials for efficient photocatalytic dye degradation and strong anti-biofilm activity

Plasmonic silver nanoparticles (AgNPs) doped ZnO (Ag-ZnO) nanoplates were synthesized by simple wet chemical method in presence of hexylamine with an intent to improve the visible light mediated photocatalytic activity of ZnO. Powder X-ray diffraction (PXRD) analysis confirmed the integration of AgNPs with ZnO nanoplates. High-resolution transmission electron microscopic (HR-TEM) and X-ray photoelectron spectroscopy (XPS) analysis confirmed the formation of ZnO nanoplates and AgNPs doping. The concentration of Ag in ZnO nanoplates was increased by increasing hexylamine concentration. Ag-ZnO hybrid nanoplates exhibited efficient degradation of organic dyes (methyl orange (MO), methylene blue (MB), Eosin Y (EY) and rhodamine B (RB)) in presence of sun light compared to the pristine ZnO. Further, AgNPs doping with ZnO strongly enhanced anti-biofilm activity and showed strong prevention of colonization. The increase of AgNPs concentration in ZnO nanoplates exhibited enhancement of both photocatalytic and anti-biofilm activity that might be attributed to the improved light absorption in the visible region.

Highly stable ammonium ion-selective electrodes based on one-pot synthesized gold nanoparticle-reduced graphene oxide as ion-to-electron transducers

An effective transducer for all-solid-state ion-selective electrodes (SC-ISEs) was developed based on gold nanoparticle-reduced graphene oxide (AuNP-rGO) hybrid material. The AuNP-rGO composite was synthesized via a simple, eco-friendly, and one-pot method with sodium citrate as the reducing agent and the stabilizer. The nanocomposite was deposited on the GC substrate via the drop-casting method and then covered with an ammonium ion-selective membrane (NH4+-ISM) to form the potentiometric electrode. The AuNP-rGO layer possessed a large surface area, high capacitance, and good hydrophobicity; thereby effectively enhancing the potential stability of the electrode without the formation of an aqueous layer. The electrode also exhibited a rapid potential response (<10 s) to NH4+ ions, an excellent Nernstian response with a slope of 56.94 (±1.57) mV/decade, a detection range of 10-5 − 10-2 M, and a detection limit of 3.80 × 10-6 M. The proposed electrode also exhibited outstanding properties including insensitivity to interferences (light, oxygen, carbon dioxide, and redox species), good reproducibility, and long operating life. The electrode has been successfully applied for NH4+ detection in real water samples, which makes it a promising alternative for developing effective and robust SC-ISEs.

Enhanced Electrochemical Ethanol Sensitivity on Ni/NiO‐rGO Hybrids Nanostructures at Room Temperature

AbstractHerein, we depict that the consequential nickel/nickel oxide‐reduced graphene oxide (Ni/NiO‐rGO) hybrid materials synthesized by sol‐gel approach can give as competent electrocatalyst for oxidative determination of ethanol in alkaline condition. Ni/NiO‐rGO based electrochemical sensor shows rapid and highly sensitive linear sweep voltametric (LSV) response to ethanol at an ultra‐low oxidation potential of 0.33 V vs. SCE. Moreover, the electrochemical sensor demonstrates highly stable (current and potential) also with low charge transfer resistance confirmed from chronoamperometic (i‐t) and electrochemical impedance spectroscopic (EIS) data respectively towards ethanol oxidation at Ni/NiO‐rGO hybrid interface confirms its acitivity over individuals i. e. Ni/NiO nanoparticles and rGO. Moreover, linear increase in current density upto 100 μM concentration of ethanol and for the scan rates in the range of 10–100 mV/s with positive shift in potential confirms ethanol oxidation is diffusion controlled process. The selective analysis of electrochemical response for ethanol in benadryl sample with same oxidation potential of ethanol beverages with enhanced ethanol oxidation potential for determination of ethanol concentration into benadryl sample analysis.

High Performance Solution Processed Oxide Semiconductors and Hybrid Materials for Flexible Electronics

High Performance Solution Processed Oxide Semiconductors and Hybrid Materials for Flexible Electronics

Recent progress in the design of advanced MXene/metal oxides-hybrid materials for energy storage devices

• Advances in the synthesis of 2D MXenes/metal-oxide hybrid materials for energy storage devices are explored. • The physical, chemical, morphological and electrochemical properties and challenges related to stability and restacking of 2D MXenes are discussed. • 2D MXenes/metal oxide hybrid cathode, anode, and electrolyte materials for various energy storage devices were comprehensively reviewed. • A detailed comparison of mechanism, cost, technical maturity, and recent development is developed. • The progress and strategies to enhance the performance of 2D MXenes/metal oxide hybrid for energy storage devices are discussed. The family of two-dimensional (2D) transition metal carbides, nitrides, and carbonitride, also called MXenes, have emerged as an attractive platform for constructing functional materials with enhanced properties for various energy applications. Transition metal oxides (TMOs) nanostructures supported on MXene nanosheets based on van der Waals interactions are facile, highly efficient, and low-cost, with self-assemble properties that can easily control their packing density. The resulting TMOs/MXene nanocomposites perfectly integrate the advantages of both components. MXene nanosheets can serve as conductive substrates to grow TMOs nanostructures which can facilitate fast electron and ion transport to prevent aggregation of TMOs nanostructures in energy applications. In turn, the TMOs nanostructures act as spacers to isolate the MXene nanosheets and prevent their re-stacking during assembly, enriching interfacial contacts and preserving the active sites. In this review, the recent advances of MXene/TMOs-based nanocomposites with enhanced performance for energy storage devices, such as supercapacitors (SCs), metal-ion hybrid capacitors (MIHCs), and various kinds of rechargeable batteries (RBs), are summarized and highlighted. We briefly discuss the synthesis methods, properties of MXenes, and the structural engineering of MXenes by introducing functionalized TMOs to achieve high-performance energy storage devices, such as in SCs, MIHCs, and RBs. Special attention is also given to MXene/TMOs nanocomposites-based SCs, HCs, metal-ion batteries, and metal-air/sulfur batteries. Finally, the crucial future outlook and perspective for developing MXene/TMOs nanocomposites for energy storage applications are also outlined. After a brief discussion on energy storage technologies and their mechanisms and environmental impacts, the advances in synthesizing 2D MXenes/metal oxide hybrid materials with physical, chemical, morphological, and electrochemical properties and challenges related to stability and restacking are discussed. 2D MXenes/metal oxide hybrid cathode and anode materials for various energy storage devices were comprehensively reviewed and compared in terms of their mechanism, cost, technical maturity, and recent development. Finally, the progress and strategies to enhance the performance of 2D MXenes/metal oxide hybrid for RBs are discussed .

Functionalized graphene oxide-zinc oxide hybrid material and its deployment for adsorptive removal of levofloxacin from aqueous media

This work reports on the synthesis of aspartic acid-functionalized graphene oxide-zinc oxide, as a functional porous material, and its potential to mitigate levofloxacin (LFXN). The adsorbent was characterized by various techniques, including ultraviolet–visible (UV–Vis), Fourier transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (PXRD), and scanning electron microscopy (SEM). The average crystallite size of the prepared composite was about 17.30 nm. Batch adsorption studies were carried out to elucidate the adsorption process for LFXN. Different parameters, including contact time, LFXN initial concentration, adsorbent concentration, pH, temperature, and ionic strength were studied. The mechanism and kinetics were studied by fitting the data to Freundlich and Langmuir isotherms, pseudo-first-order and pseudo-second-order kinetic models, respectively. The isotherm data was better fitted to Langmuir isotherm (R2 = 0.999) as compared to the Freundlich model. The maximum adsorption capacity obtained at equilibrium was 73.15 mg/g. For kinetic studies, Pseudo first order was better fitted with R2 = 0.87797, confirming the physisorption process. Thermodynamics parameters revealed that the process was exothermic and spontaneous at low temperatures. The adsorption mechanism was studied and the impregnation of LFXN in the adsorbent was confirmed by FTIR studies. This research proved that the designed GO/Asp-ZnO was a novel and promising adsorbent for the removal of LFXN with an efficiency of 95.12% at 30 mg/L LFXN by 0.6 g/L adsorbent in 24 h at pH = 7 and T = 25 °C.

Rational synthesis of reduced graphene oxide hybrid nanocomposite with iron tungstate for selective detection of epinephrine in biological fluids

Hybrid nanocomposites made from metal tungstate and stacked graphene nanosheets have attracted the curiosity of researchers due to their high conductivity, strong electrochemical activity, and quick electrochemical transfer response. These properties prompted us to employ co-precipitation and sonochemical approaches to create low-cost iron tungstate (FeWO4)/reduced graphene oxide (rGO) hybrid material. The as-synthesized FeWO4/rGO nanocomposites (NCs) were evaluated for their physicochemical properties and structural and morphological aspects. A modified electrode composed of FeWO4/rGO NCs was utilized to detect epinephrine (Eph), a significant neurotransmitter and hormone associated with various human activities. The electrochemical behavior of Eph was quantified using cyclic voltammetry, and differential pulse voltammetry (DPV) on a FeWO4/rGO NCs modified electrode. According to the DPV study, Eph concentration was linearly distributed from 0.05 to 990.5 µM. For determining Eph, the sensor had a detection limit of 0.0073 µM and a sensitivity of 5.857 µAµM−1 cm−2. The sensor displayed excellent recovery results for the determination of Eph in the human urine and epinephrine pills real samples, revealing its excellent practicality.

Electrical Properties of Polyetherimide-Based Nanocomposites Filled with Reduced Graphene Oxide and Graphene Oxide-Barium Titanate-Based Hybrid Nanoparticles.

The electrical properties of nanocomposites based on polyetherimide (PEI) filled with reduced graphene oxide (rGO) and a graphene oxide hybrid material obtained from graphene oxide grafted with poly(monomethyl itaconate) (PMMI) modified with barium titanate nanoparticles (BTN) getting (GO-g-PMMI/BTN) were studied. The results indicated that the nanocomposite filled with GO-g-PMMI/BTN had almost the same electrical conductivity as PEI (1 × 10−11 S/cm). However, the nanocomposite containing 10 wt.% rGO and 10 wt.% GO-g-PMMI/BTN as fillers showed an electrical conductivity in the order of 1 × 10−7 S/cm. This electrical conductivity is higher than that obtained for nanocomposites filled with 10% rGO (1 × 10−8 S/cm). The combination of rGO and GO-g-PMMI/BTN as filler materials generates a synergistic effect within the polymeric matrix of the nanocomposite favoring the increase in the electrical conductivity of the system.

Resistive switching memory based on polyvinyl alcohol-graphene oxide hybrid material for the visual perception nervous system

Resistive random-access memory (RRAM) is a new memory technology that can not only realize high-density storage, but also can simulate the neural synapse for use in artificial intelligence applications. In this study, we propose an RRAM device that shows competitive resistive memory characteristics and can similarly be used as a synapse in simulation of the human visual perception nervous system. First, we demonstrate that the polyvinyl alcohol-graphene oxide (PVA@GO) hybrid material-based RRAM device offers competitive resistive memory characteristics, including long retention capability, high durability, repeatability, and mechanical flexibility. Second, we integrate the RRAM (as the artificial synapse) with a light-sensitive electronic component (a photoreceptor cell) to construct an artificial visual perception system, and realize effective emulation of light perception and conversion of light signals into synaptic signals. Under light irradiation at 532 nm, a range of versatile synaptic functions, including short-term plasticity (STP), long-term plasticity (LTP), and paired pulse facilitation (PPF), was imitated. This work provides valuable insight into the development path for next-generation high-density data storage technology, and also offers a new way to imitate the human visual neural network for multi-functional humanoid robots.

Capacitive Properties of Chlorine Doped Graphene Quantum Dots Anchored into Reduced Graphene Oxide

In this study, Cl-GQDs anchored into pure reduced graphene oxide (Cl-GQDs/rGO) hybrid materials were hydrothermally fabricated and characterized by various analyses. Meanwhile, P-GQDs, S-GQDs and N-GQDs were also fabricated and anchored into rGO as controls. The AFM images of Cl-GQDs, P-GQDs, N-GQDs and S-GQDs displayed the average height of 1–3 nm, 1–1.5 nm, 1.5–2.0 nm and 4.0–4.5 nm, respectively. Moreover, the absorbance and fluorescence spectra of Cl-GQDs were different from those of other doped graphene quantum dots. Cyclic voltammetry and galvanostatic charge-discharge curves were employed to analyze the capacitive performances of doped-GQDs/rGO. At the current density of 2 A g−1, the capacitance of Cl-GQDs/rGO achieved 316 F g−1, which was about 3 times, 2 times and 1.5 times as high as that of rGO, S or N-GQDs/rGO and P-GQDs/rGO, respectively. At the power density of 1.1−3.3 KW Kg−1, Cl-GQDs/rGO reached the energy density of 53.2 − 32.1 Wh Kg−1. Electrochemical impedance spectroscopy clearly indicated that Cl-GQDs could improve the conductivity of rGO in the electrochemical reaction, resulting in superior capacitive performances.

Synthesis of a novel fluorinated graphene oxide hybrid material based on poly(2,3,4,5,6-pentafluorostyrene) and its use as a filler for thermoplastic polyurethane film

In this study, graphene oxide (GO) was synthesized via modified Hummers method. The GO was grafted with poly(2,3,4,5,6-pentafluorostyrene) (PPFSGO) by surface initiated atom transfer radical polymerization (SI-ATRP). This material was used as a novel filler for thermoplastic polyurethane (TPU) to prepare composite films via solution casting method. FTIR, Raman and XRD spectroscopy analyses confirmed the formation of proposed hybrid structure. SEM analysis indicated that the GO layers of PPFSGO were exfoliated and decorated with weblike PPFS. Particularly, the contact angle measurements showed that the contact angle of TPU based composite films could be increased by 20% compared to bare TPU film with the incorporation of 10 wt% of PPFSGO while preserving thermal stability and electrically insulating properties. These results revealed that the herein proposed PPFSGO hybrid material is a promising candidate to adjust the wettability of TPU films without compatibility issues.

Preparation of Silver Decorated Reduced Graphene Oxide Nanohybrid for Effective Photocatalytic Degradation of Indigo Carmine Dye

Background: Even though silver decorated reduced graphene oxide (Ag-rGO) shows maximum absorptivity in the UV region, most of the research on the degradation of dyes using Ag-rGO is in the visible region. Therefore the present work focused on the photocatalytic degradation of indigo carmine (IC) dye in the presence of Ag-rGO as a catalyst by UV light irradiation. Methods: In this context, silver-decorated reduced graphene oxide hybrid material was fabricated and explored its potential for the photocatalytic degradation of aqueous IC solution in the UV region. The decoration of Ag nanoparticles on the surface of the rGO nanosheets is evidenced by TEM analysis. The extent of mineralization of the dye was measured by estimating chemical oxygen demand (COD) values before and after irradiation. Results: The synthesized Ag-rGO binary composites displayed excellent photocatalytic activity in 2 Χ 10-5 M IC concentration and 5mg catalyst loading. The optical absorption spectrum of Ag-rGO showed that the energy band-gap was found to be 2.27 eV, which is significantly smaller compared to the band-gap of GO. 5 mg of Ag-rGO was found to be an optimum quantity for the effective degradation of IC dye. The degradation rate increases with the decrease in the concentration of the dye at alkaline pH conditions. The photocatalytic efficiency was 92% for the second time. Conclusion: The impact of the enhanced reactive species generation was consistent with higher photocatalytic dye degradation. The photocatalytic mechanism has been proposed and the hydroxyl radical was found to be the reactive species responsible for the degradation of dye. The feasibility of reusing the photocatalyst showed that the photocatalytic efficiency was very effective for the second time.