Oxy-functional Groups Research Articles

Insights into the Unanticipated Chemical Reactivity of Functionalized Nanosheets Derived from TiB2.

Titanium diboride (TiB2) is a member of the AlB2-type layered metal boride family; the materials of this family are receiving renewed research interest owing to their amenability to nanoscaling. Earlier, we showed that TiB2 can be nanoscaled to yield quasi 2D nanostructures following a dissolution-recrystallization approach. This approach yielded nanosheets that were chemically functionalized with oxy-functional groups. Also, these nanosheets could inherently form a gel-like substance. In this work, we show that these functionalized nanosheets can interact with ascorbic acid in a way that first imparts a characteristic orange hue to the original yellowish nanosheet dispersion. Second, this interaction results in the loss of gel-like behavior of the nanosheet dispersion. We utilize several spectroscopic techniques such as UV-visible, FT-IR, NMR, EPR, XPS, and XANES to unravel this unexplored chemical interaction. The findings show that both titania as well as oxy-boron species react with ascorbic acid, leading to a profound modification of the nanosheets. This modification results in an augmented electrochemical response, implying that the modified nanosheets can be used in novel applications. This study is therefore a step toward gaining an even deeper understanding of the chemical opportunities that these nanoscaled borides can provide.

Boosting Fenton's Oxidation Reaction by a Food Waste-Derived Catalyst for Oxidizing Organic Dyes: Synergistic Effect of Complex Iron Oxides and the Layer Carbon Structure.

The constant increase in the human population drives the demand for food supply and thereby increasing the food wastage dramatically all over the world. Especially, around 60% of banana biomass has been generated as inedible domestic waste. Herein, we successfully employed banana waste as a catalyst for Fenton's oxidation reaction. The biomass-derived catalysts were subjected to various characterization techniques such as XRD, ATR-FTIR, confocal Raman spectroscopy, and XPS, XRF, BET, SEM, and TEM analyses. The XRD results revealed that, after carbonization of the dried banana bract material, a perloffite-like metal oxide phase was formed due to the aerial oxidation reaction. Characterization results of Raman and ATR-FTIR confirm that the carbonized catalyst possesses a layer-like structure with different types of functional groups. The calcium, magnesium, potassium, sodium, and iron are the dominating metal species in the resultant material, which was evident from the XRF and EDAX analyses. The carbonized banana bract catalyst is successfully utilized for the Fenton's oxidation reaction at neutral pH. The experimental results showed that the degradation efficiency of the fresh catalyst was 95% in 4 h of reaction time, and the stability of the catalyst was retained up to nine consecutive cycles. The high activity of MB, methylene blue, is mainly attributed to the strong interaction between oxy functional groups of the catalyst and MB molecule as compared to RhB. Further, the calculated efficiency of the hydrogen peroxide was found to be 99% and the self-decomposition of hydrogen peroxide by the formed metal oxides was highly limited.

Solid-state single-step synthesis of FeNbO4 perovskite modified nickel foam for electrochemical detection of Creatine phosphokinase in simulated human blood serum

Creatine phosphokinase (CPK-MM), is an important constituent of active muscle, acts as a vital enzyme in intracellular energy transport and is a potential biomarker for diseases like muscular dystrophy (MD), acute renal failure, and muscle damage. Herein, we report a single-step solid-state synthesis of niobium iron oxide(FeNbO4) modified nickel foam (FeNbO4/NF) for non-enzymatic detection of CPK-MM in simulated human blood serum. The X-ray diffraction (XRD) reveals an orthorhombic phase formation of FeNbO4 with (111) family of planes. The FeNbO4/NF exhibits a low limit of detection (i.e., 0.75 μg/L) and high sensitivity of 1.9 mA/x. cm−2 (x = μg/L) with a wide linear range of detection ranging from 1 μg/L to 100 μg/mL. This performance of the sensor can be attributed to the excellent electrocatalytic activity of the FeNbO4 nanomaterial facilitating the effective redox reaction of the CPK. In this mechanism, the presence of oxy functional groups on the surface of FeNbO4/NF facilitates the interaction between the electrocatalytic active sites of the electrode and the CPK-MM molecules. In addition, this sensor exhibits outstanding selectivity (in presence of different interfering species like ascorbic acid, bovine serum albumin, urea, and uric acid) with good stability as well as reproducibility. The sensor is found successful in the determination of CPK-MM concentration in simulated blood serum samples with good recovery percentages. This efficacy of the as-fabricated electrode demonstrates the FeNbO4 as a potential platform for various electrochemical-based bioanalytical applications.

Titanium diboride (TiB2) derived nanosheets enhance the CO2 capturing ability of Calcium Oxide (CaO)

Several two-dimensional (2D) materials are being actively explored as additives for enhancing CO2 capture owing to their high surface area, superior thermal stability, and extremely high density of catalytically active sites. The landscape of 2D materials is constantly expanding as several van der Waals and ionic layered materials are being revisited with the view of exfoliation. Recently, we have been able to nanoscale titanium diboride (TiB2), a layered metal diboride ceramic primarily investigated in its bulk form. We have developed various approaches to exfoliate TiB2 into nanosheets that contain titanium and boron atoms decorated with oxy-functional groups such as TiO2, BO33−, and BO4− known to capture CO2 gas molecules. This aspect motivated us to examine if nanosheets derived from TiB2 can enhance the capturing capacity of CO2 adsorbent material. Calcium oxide (CaO)-based materials are widely used as regenerable CO2 adsorbents at high temperatures due to their high CO2 reactivity, easy recyclability, and low cost. However, the adsorption capacity of these materials drastically decreases with multiple carbonation-calcination (decarbonation) cycles due to particle agglomeration. This shortcoming led us to investigate the effect of TiB2 based nanosheets on the CO2 capturing ability of CaO. In this work, we show that adding just 1% of nanosheets can enhance the capturing capacity of CaO up to 25% and results in lesser sintering of CaO. We also utilized minimally functionalized nanosheets derived from TiB2 to show how the density of functional groups present on the surface of these nanosheets can affect the CO2 capturing ability of CaO. We utilized these to obtain preliminary insights on the reaction mechanism of CO2 adsorption on CaO and rate parameters through the reaction kinetics. To the best of our knowledge, this is the first study presenting a new perspective on using nanoscaled metal diborides to enhance CO2 capture.

Stripping voltammetry and chemometrics assisted ultra-selective, simultaneous detection of trace amounts of heavy metal ions in aqua and blood serum samples

We present a one-step, solid-state synthesis of Al2NiCoO5 nanoflakes (ANC) modified glassy carbon electrode (GCE) for ultra-selective and trace level simultaneous detection of HMIs like copper (Cu2+), mercury (Hg2+), cadmium (Cd2+), and lead (Pb2+) ions in aqua and simulated blood serum samples. ANC/GCE sensor exhibits a low limit of detection (LOD = 3S/m) of 0.00154 ppb, 0.00232 ppb, 0.00261 ppb and 0.00114 ppb towards Pb2+, Hg2+ Cu2+ and Cd2+ ions, correspondingly that are far lower than the perilous limits of HMI concentration reported for blood serum and water samples. The quantitative study and multiple response analysis of the sensor towards each metal ions are accomplished via principal component analysis (PCA) which verifies the selectivity of the ANC/GCE sensor with satisfactory recovery percentages. The superior performance, reproducibility and stability of the sensor are attributed to the electrocatalytic active sites of ANC nanoflakes facilitated by the Ni2+/Ni3+ and Co2+/Co3+ redox couple along with the oxy-functional groups. The sensor was efficacious in detecting the trace level concentrations of HMIs in samples like simulated blood serum, drinking water and tap water with good recovery percentages. This efficiency of the sensor demonstrates it as a promising platform for a broad-spectrum of environmental and bioanalytical applications.

Ultra-Selective and Wide Range Detection of D-Mannitol in Human Blood Samples via Differential Pulse Voltammetry Technique Using MgAl2O4 Perovskite Modified Electrode

Herein, we present the first report on label-free electrochemical sensing of D-Mannitol using MgAl2O4 Nanopowder (MAO) modified glassy carbon electrode (GCE) sensor for pico-molar detection of D-Mannitol in biological samples. The differential pulse voltammetry (DPV) technique is employed for the sensing of D-Mannitol over a wide linear range of detection ranging from 1 pM to 1.5 nM with a sensitivity of 6.47 nA/pM cm−2 and an ultra-low limit of detection (LOD, $3\sigma $ ) of 0.371 pM. The sensor shows an excellent selectivity towards D-Mannitol in the presence of interfering analytes such as glucose, sucrose, human serum albumin (HSA) and bovine serum albumin (BSA). Additionally, the sensor exhibits successful reproducibility with n = 5 devices and excellent stability. This enhanced performance of the MAO/GCE is attributed to the excellent electrocatalytic property of MAO thru Al2+/Al2+ redox couple facilitating the redox reaction of D-Mannitol and the presence of oxy functional groups which improves the adsorption process of D-Mannitol oxidase (mannose) onto the surface of MAO/GCE. The as-fabricated sensor could successfully determine D-Mannitol in the biological samples with excellent recovery percentages from ~98.2% to ~110.42% thus proving to be an excellent platform for developing low cost, high-performance bioanalytical sensing systems.

Highly selective trace level detection of Atrazine in human blood samples using lead-free double perovskite Al2NiCoO5 modified electrode via differential pulse voltammetry

In this work, we demonstrate trace level electrochemical detection of atrazine in human blood serum samples based on lead-free double perovskite material Al2NiCoO5 (ANCO) modified glassy carbon electrode (GCE). The SEM micrographs confirm the nanoflakes morphology of the ANCO synthesized via solid-state technique while XRD, Raman and FTIR analysis reveal the crystal structure, vibrational modes and the existence of OH− groups at the surface area of the ANCO nanoflakes. The as-fabricated ANCO/GCE exhibits a low limit of detection (LOD) of 0.3 ppb and a linear range of 0.5 ppb – 100 ppb atrazine with a sensitivity of 0.929 μA/ppb cm2. This enhanced performance of ANOC/GCE is ascribed to the electrocatalytic active sites of ANOC nanoflakes facilitated with Ni2+/Ni3+ and Co2+/Co3+ redox couple along with the oxy functional groups. The sensor exhibits an outstanding selectivity towards atrazine in presence of 100 folds of Na+, Ca2+, bovine serum albumin (BSA) and human serum albumin (HSA). The sensor is successful in the detection of atrazine in human blood serum samples with outstanding recovery percentages from ∼97.05 to ∼103.27 % thus making it an ideal platform for developing a wide range of electroanalytical sensors in biological samples.

Graphene-based nanostructures for enhanced photocatalytic degradation of industrial dyes

Graphene oxide (GO) is an sp2-bonded single atomic layer of carbon atoms with plenty of oxy-functional groups at its surface. The occurrence of large surface area (~ 2630 m2/g), surface functionalities, electronic, and mechanical properties make graphene-based compounds favorable for remediation applications. We report the synthesis and comparative dye degradation efficiencies of two titania (TiO2)-based composites, GO-TiO2, and reduced GO-TiO2 (rGO-TiO2). Both the composites are characterized using SEM-EDX, TEM, FTIR, and XRD. We study the photocatalysis-mediated degradation of anionic dye Eosin Y and cationic dye Methylene blue (MB) in aqueous dispersions under white light and UV irradiation. Our results demonstrate that rGO(10 wt%)-TiO2 composite shows the maximum degradation (~ 95%) of both 10 ppm Eosin Y and MB dyes in the aqueous dispersion. The enhanced photocatalytic activity of rGO-TiO2 composites as compared to TiO2 and GO-TiO2 can be credited to the presence of efficient electron shuttling from the conduction band of TiO2 into the conductive regions of graphene which eventually restricts further recombination of e−/h+ pairs. Furthermore, the effects of solution pH and TiO2 loading are studied on the degradation process.

Ultra-selective, trace level detection of As3+ ions in blood samples using PANI coated BiVO4 modified SPCE via differential pulse anode stripping voltammetry.

We report a novel, facile hydrothermal synthesis of bismuth vanadate (BiVO4) nanoflakes coated with polyaniline (PANI) via electrodeposition on screen-printed carbon electrode (SPCE) for trace level detection of arsenic in biological samples. The crystallinity and monoclinic scheelite structure of as-synthesised BiVO4 nanoflakes was analysed using X-Ray diffraction (XRD) and the surface morphology and chemical analysis of the flake-like BiVO4 and PANI coated BiVO4 modified SPCE (PANI@BiVO4/SPCE) were studied using Field emission scanning electron microscopy (FESEM), Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR). The presence of VO4 tetrahedra and VO43- group along with oxy-functional groups were confirmed using Raman and FTIR analysis, respectively. Under optimized conditions, the sensor could detect As3+ ions via differential pulse anodic stripping voltammetry (DPASV) technique with remarkable low limit of detection (LOD) of 0.0072ppb (which is far below the MCL testified values) and exhibited a sensitivity of 6.06μAppb-1cm-2 for a linear range of 0.01 to 300ppb. This improved sensing aptitude can be ascribed to the synergetic effect of PANI and BiVO4 by providing high electrical conductivity and high electrocatalytic active sites via VO43- tetrahedra, respectively. The sensor showed an outstanding selectivity in detection of As3+ ions in trace levels in simulated blood serum samples with excellent recovery percentages thus making it an ideal platform to develop numerous electrochemical sensing platforms for bioanalytical applications.

Total Syntheses of Allelopathic 4-Oxyprotoilludanes, Melleolides, and Echinocidins.

Stereocontrolled total syntheses of allelopathic 4-oxyprotoilludane sesquiterpenes, melleolide, melleolide F, and echinocidins B and D were achieved. The curved 5/6/4 tricyclic system with an angular hydroxy group was built via three key transformations: (1) Me3Al-catalyzed [2 + 2] cycloaddition of a ketene silyl acetal with a propiolate, (2) reductive ring-opening of a cyclic hemiketal, and (3) the intramolecular Morita-Baylis-Hillman reaction. This synthetic route represents a new and reliable strategy to obtain protoilludanes with several oxy-functional groups.

Molecular modeling approach to elucidate gas phase hydrodeoxygenation of guaiacol over a Pd(111) catalyst within DFT framework.

Excessive amounts of oxy-functional groups in unprocessed bio-oil vitiate its quality as fuel; therefore, it has to be channelized to upgrading processes, and catalytic hydrodeoxygenation is one of the most suitable routes for the upgrading of crude bio-oil. In this computational work, catalytic hydrodeoxygenation (HDO) of guaiacol, which is an important phenolic compound of crude bio-oil, has been carried out using density functional theory (DFT) over a Pd(111) catalyst. The Pd(111) catalyst surface does not endorse direct eliminations of functional groups of guaiacol; however, it is found to perform excellently in stepwise dehydrogenation reactions of oxy-functionals of guaiacol according to present DFT results. The catechol product, formed through dehydrogenation of the methoxy group, followed by elimination of CH2 and association of the hydrogen atom, has been identified as one of the major products. The overall reaction rate is controlled by scission of CH2 from 2-methylene-oxy-phenol with an activation energy demand of 23.06kcal mol-1. Further, the kinetic analysis of each reaction step involved in HDO of guaiacol over the Pd(111) catalyst surface has also been carried out at atmospheric pressure and at a wide range of temperatures from 473 to 673K, with temperature intervals of 50K. In the kinetic analysis part, various kineticparameters, such as forward and reverse reaction rate constants, Arrhenius constants, and equilibrium rate constants, are reported. The kinetic modeling of the dominating reaction steps has revealed that even a lower temperature of 473K provides a favorable reaction environment; and the temperature increment further improves the reaction favorability.

Direct chemical conversion of xylan into furfural over sulfonated graphene oxide

Graphene oxide (GO) grafted with –SO3H group giving a Brønsted acidic function was successfully applied for selective conversion of xylan to furfural (FA), which can be utilized as a platform chemical for a variety of value-added derivatives. The sulfonated graphene oxide (GO–SO3H) was, for the first time, found to be superior for the selective production of FA with 86% yield from xylan in water as a green solvent. GO–SO3H was successfully recycled after the reaction, and retained its catalytic activity without significant reduction. It is noteworthy that the Brønsted acid site acts as a key role in the production of furfural from xylan. Additionally, the presence of oxy-functional groups not only strengthen grafting of –SO3H with GO which probably prevented leaching into the reaction medium, but also helps to enhance the sorption capacity of substrate on GO-SO3H.

A Flexible and Divergent Strategy to Flavonoids with a Chiral A-Ring Featuring Intramolecular Michael Addition: Stereoselective Synthesis of (+)-Cryptocaryone, (+)-Cryptogione F, and (+)-Cryptocaryanones A and B, as Well as (+)-Cryptochinones A and C.

A flexible strategy has been developed to synthesize divergent flavonoids bearing a chiral A-ring. As two key steps, the coupling via a boron-mediated aldol condensation and the cyclization via a highly stereoselective intramolecular Michael addition of 1,3-diketone proceed under mild conditions; thus, the chiral flavonoids bearing C-7 oxy functional groups or olefinic bonds are both easily accessible. Using this approach, the first synthesis of (+)-cryptogione F, (+)-cryptocaryanone B, and (+)-cryptochinones A and C, as well as stereoselective synthesis of (+)-cryptocaryone and (+)-cryptocaryanone A, were achieved from 2-deoxy-d-ribose in high overall yields.

Simple, Green, and High-Yield Production of Boron-Based Nanostructures with Diverse Morphologies by Dissolution and Recrystallization of Layered Magnesium Diboride Crystals in Water.

Layered metal diborides that contain metal atoms sandwiched between boron honeycomb planes offer a rich opportunity to access graphenic forms of boron. We recently demonstrated that magnesium diboride (MgB2 ) could be exfoliated by ultrasonication in water to yield boron-based nanosheets. However, knowledge of the fate of metal boride crystals in aqueous phases is still in its incipient stages. This work presents our preliminary findings on the discovery that MgB2 crystals can undergo dissolution in water under ambient conditions to result in precursors (prenucleation clusters) that, upon aging, undergo nonclassical crystallization preferentially growing in lateral directions by two-dimensional (2D) oriented attachment. We show that this recrystallization can be utilized as an avenue to obtain a high yield (≈92 %) of boron-based nanostructures, including nanodots, nanograins, nanoflakes, and nanosheets. These nanostructures comprise boron honeycomb planes chemically modified with hydride and oxy functional groups, which results in an overall negative charge on their surfaces. This ability of MgB2 crystals to yield prenucleation clusters that can self-seed to form nanostructures comprising chemically modified boron honeycomb planes presents a new facet to the physicochemical interaction of MgB2 with water. These findings also open newer avenues to obtain boron-based nanostructures with tunable morphologies by varying the chemical milieu during recrystallization.

The role of ozone in the formation and structural evolution of graphene oxide obtained from nanographite

Chemical exfoliation of graphite under strong oxidizing conditions yields graphene oxide nanosheets with oxy functional groups on the carbon basal plane. The importance of ozone in the chemical oxidation mechanism of graphite by the widely-used Hummers' method has been largely overlooked. Herein we demonstrate that the ozonolysis of graphite leads to the formation of secondary epoxy and peroxymonosulfate ester functional groups arising from a rotationally hindered Criegee intermediate and sulfuric acid, in a strongly favored thermodynamic process. This mechanistic step is followed by formation of adjacent epoxy and hydroxy groups as major functionalities on graphene oxides via a radical process, and leaves a significant amount of unreacted peroxides well above levels previously recognized. The thermal decomposition of graphene releases sulfur oxygen species (SO2 and SO), but does not appear to release ozone even if this reaction pathway is moderately favored thermodynamically. We propose a new structural model for graphene oxide based on detailed chemical and spectroscopic data that provides insight into observed chemical reactivity and physical properties, including the antimicrobial activity and protein deactivation.

Synthesis of some metallophthalocyanines bearing 9-phenyl-9H-fluoren-9-yl) oxy functional groups and investigation of their photophysical properties

As starting material, 4-((9-phenyl-9H-fluoren-9-yl) oxy) phthalonitrile (3) was synthesized and characterized. Cobalt (4), zinc(5), and magnesium(6) phthalocyanines were obtained by reaction of starting material with corresponding metal salt. The new synthesized phthalonitrile derivative (3) was characterized by X-ray crystallography in addition to with other spectroscopic methods. Phthalocyanine complexes were characterized by using electronic absorption, nuclear magnetic resonance spectroscopy, infrared and mass spectra. Furthermore, spectroscopic and photophysical properties such as absorption, excitation, and emission spectra of zinc and magnesium phthalocyanines were investigated in tetrahydrofuran solutions. Of compounds were determined the fluorescence lifetimes and the fluorescence quantum yields. The aggregation behavior for phthalocyanine complexes were carried out in tetrahydrofuran.

Ru nanoparticles supported graphene oxide catalyst for hydrogenation of bio-based levulinic acid to cyclic ethers

Ruthenium nanoparticles supported on graphene oxide (GO) catalysts have been evaluated for bio-based levulinic acid (LA) hydrogenation to produce vapor-phase cyclic ethers in a fixed-bed reactor. It was found that using the GO supported Ru nanoparticles (Ru/GO) produced additional hydrogenation products – cyclic ethers (54%) and γ-valerolactone (GVL; 41%), while Ru on carbon (Ru/C) catalysts gave only GVL with 100% LA conversion. To improve the yield of cyclic ethers, an additional two-step hydrogenation of LA via GVL was successfully carried out. This provided GVL as a second feedstock from which the Ru/GO catalyst could produce cyclic ethers such as methyltetrahydrofuran (MTHF) and tetrahydrofuran (THF). Ru on GO catalysts showed a 92% selectivity of predominantly cyclic ethers, including a 77% selectivity of MTHF through two steps process. Such a remarkable enhancement in activity and selectivity of LA hydrogenation over Ru/GO can be attributed to the well-dispersion of Ru nanoparticles, as well as favorable interaction with GO in the presence of oxy-functional groups of GO. In order to evaluate the active sites on the catalyst, they were characterized using different characterization techniques such as Raman, XRD, X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction (TPR), temperature-programmed desorption of NH3 (TPD), electron microscopy (TEM and SEM) and H2-chemisorption and N2 adsorption.

Study of Electronic and Magnetic Properties of Nitrogen Doped Graphene Oxide

The Nitrogen doped graphene oxide (NGO) was synthesized by doping N-atoms on graphene oxide (GO) sheet by using melamine which serves as the nitrogen source, through hydrothermal approach. The insertion of nitrogen atoms into the graphene oxide sheet was confirmed by FT-IR, EDS and Raman spectroscopic techniques. We also probed into the tuned dielectric and magnetic properties of NGO due to the decomposition of oxy functional groups of GO and the insertion of pyridinic, pyrrolic and graphitic type nitrogen atoms into the graphitic structure. The dielectric properties were measured by Broadband Dielectric Spectroscopy (BDS). The magnetic behaviour of the sample was demonstrated by Vibrational Scanning Magnetometer (VSM).

One-step potentiodynamic synthesis of poly(1,5-diaminoanthraquinone)/reduced graphene oxide nanohybrid with improved electrocatalytic activity

In this work, we facilely synthesized poly(1,5-diaminoanthraquinone)/reduced graphene oxide (P(1,5-DAAQ)/RGO) nanohybrid through a one-step potentiodynamic deposition method (by changing the potential scanning range and direction), in which the 1,5-DAAQ monomer and GO acted as the starting materials. RGO was generated by cathodic electro-reduction of GO and P(1,5-DAAQ) polymer was simultaneously produced by in situ anodic electro-oxidative polymerization of the 1,5-DAAQ monomer. The morphology and microstructure of the resultant nanohybrid was fully characterized by field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). Characterizations indicate that the P(1,5-DAAQ) polymer displays a barleycorn-like structure and is covalently grafted onto the RGO surface. The electrochemical properties and electrocatalytic activity of the P(1,5-DAAQ)/RGO nanohybrid were investigated using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and rotating disk electrode (RDE) techniques. The P(1,5-DAAQ)/RGO nanohybrid shows higher electrical conductivity than that of 1,5-DAAQ/GO, since it has a lower concentration of oxy-functional groups after the potentiodynamic synthesis. The CV and RDE results reflect the fact that the P(1,5-DAAQ)/RGO nanohybrid possesses superior electrocatalytic activity toward the oxygen reduction reaction (ORR) with a long cycle life. The covalently grafted P(1,5-DAAQ) polymer on RGO sheets supplies sufficient electroactive sites (the π-conjugated system and the quinone groups), resulting in more favorable electron-transfer kinetics and greatly enhanced electrocatalytic performance for O2 reduction on the P(1,5-DAAQ)/RGO nanohybrid.

Mn2O3 decorated graphene nanosheet: An advanced material for the photocatalytic degradation of organic dyes

Abstract A one step sonochemical route has been developed to prepare graphene–Mn 2 O 3 nanocomposite with uniform distribution of Mn 2 O 3 nanoparticles throughout the surface of graphene nanosheet. Growth of such nanoparticles over this two dimensional carbon network is simply accelerated by the simultaneous reduction of potassium permanganate along with graphene oxide, in which metal ions are first anchored through binding with oxy-functional groups of graphene oxide and finally reduced by hydrazine. The final product ensure a new platform for the photodegradation of organic dyes, as it can store electrons and circulate them towards dye molecules through the formation of hydroxyl radical under the exposure of UV-light. Almost 80% photocatalytic degradation of eosin, methylene blue and rhodamine B have been observed within few minutes, which has not been obtained by using bare manganese oxide itself.