Publications

Small Fe-Cu nanoparticles (NPs) (about 1 nm) supported at a high loading (over 10 wt %) on N-doped graphitic carbon have been prepared in a single pyrolytic step from chitosan adsorbing Cu 2+ and Fe 2+ salts. The presence of N atoms appears to be crucial in the formation of small-sized metallic NPs. Interactions between Fe and Cu are reflected by a shift in the binding energy to higher (Fe) or lower (Cu) values and by H 2 thermo-programmed reduction measurements, showing a new reduction peak at intermediate temperature (375 C) between that of Cu (175 C) and that of Fe (450 C). Fe-Cu NPs embedded within the N-doped graphitic carbon matrix are extremely active (TOF 315 h -1 ) and selective (no CO detected) catalysts for methanol reforming in the aqueous phase with stoichiometric H 2 O amounts to H 2 and CO 2 . The results achieved with Fe-Cu compare favorably with those reported in the literature for catalysts based on Pt, Pd, or Ru.

The world is suffering from heavy pollution because of synthetic petrochemical plastic used in our daily activities. A possible solution is the use of bioplastic synthesized from natural renewable resources. The present work investigates the development and characterization of polymer bioplastic using ginger tea and green tea to decrease the adverse effect of petrochemical plastic waste for versatile applications. Two kinds of bioplastic samples were produced with two types of tea, ginger tea and green tea, using glycerol, vinegar, starch, and water. SEM (scanning electron microscopy), FTIR (Fourier transformed infrared spectroscopy), mechanical (tensile), TGA (thermogravimetric analysis), DSC (differential scanning calorimetry), and time tests of bioplastic degradation analysis were carried out to evaluate the morphological, mechanical, and thermal behaviors of the synthesized tea bioplastics. The research result showed ginger tea bioplastic had a maximum tensile strength of 2.9 MPa and a minimum elongation of 7.46 mm. More than 78% of degradation occurred in ginger bioplastic within 30 days. Compatible thermal and morphological characteristics are also observed in the prepared bioplastic samples.

Stabilized by a bulky N-heterocyclic carbene [^BP DPr, 1,3-bis(2,6-diisopropylphenyl)-1,3-diazonine-2-ylidene] ligand, new silver carboxylate complexes of the form ^BP DPrAgO₂ C-R (R=Me, Ph) have been synthesized and fully characterized in solution and in the solid state and implemented as sole catalysts (base-, additive-, and, in some cases, solvent-free) in the challenging fixation of carbon dioxide to unsubstituted propargylic derivatives for the synthesis of oxazolidinones and α-methylene cyclic carbonates. Derived from X-ray diffraction studies, the molecular geometry and the concept of buried volume were employed to describe the structural and steric features of these silver complexes. Their stability and efficiency as catalysts have been demonstrated by the synthesis of 29 carboxylation products (72-98 % yield) at low catalyst loadings (0.01-1.5 mol%). Characteristics are high turnover numbers (up to 9400), catalyst recyclability (up to 96 % yield after the 7th cycle with no decomposition of the silver complex), and the possibility to scale-up the reaction.

Abstract It is highly desired to develop high efficient non‐precious metal catalysts for urea oxidation and energy‐saving electrolytic hydrogen production. In this communication, we report that bimetallic NiCoP nanosheets array on carbon cloth acts as a superb and stable catalyst for urea oxidation reaction (UOR) with the need of potential of 0.455 V to achieve 50 mA cm −2 in 1.0 M KOH and 0.33 M urea. The excellent catalytic activity for hydrogen evolution reaction (HER) enables this electrode as a bifunctional UOR and HER catalyst and its two‐electrode system affords 20 mA cm −2 at a cell voltage of only 1.25 V, 360 mV smaller than that of pure water splitting, with strong long‐term electrochemical stability.

A novel electrochemical (EC) chlorobenzene (CBZ) sensor was fabricated using a ternary oxide RuO₂/ZnO/TiO₂ nanocomposite (NC)-decorated glassy carbon electrode (GCE). The nanoparticles (NPs) were synthesized by a wet-chemical method and characterized by X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), and ultraviolet-visible (UV-vis) spectroscopy. The synthesized RuO₂/ZnO/TiO₂ NC was layered as thin film on a GCE with Nafion (5% suspension in ethanol) adhesive, and the as-prepared sensor was subjected to CBZ analysis using an electrochemical approach. The calibration of the proposed CBZ sensor was executed with a linear relation of current <i>versus</i> concentration of CBZs known as the calibration curve. The sensitivity (32.02 μA μM^-1 cm^-2) of the CBZ sensor was calculated from the slope of the calibration curve by considering the active surface area of the GCE (0.0316 cm²). The lower detection limit (LD; 98.70 ± 4.90 pM) was also calculated at a signal-to-noise ratio of 3. Besides these, the response current followed a linear relationship with the concentration of chlorobenzene and the linear dynamic range (LDR) was denoted in the range of 0.1 nM to 1.0 μM. Moreover, the CBZ sensor was found to exhibit good reproducibility, reliability, stability, and fast response time. Finally, the sensing mechanism was also discussed with the energy-band theory of ternary doped semiconductor materials. The sensing activity of the proposed sensor was significantly enhanced due to the combined result of depletion layer formation at the heterojunction of RuO₂/ZnO/TiO₂ NCs as well as the activity of RuO₂ NPs as oxidation catalysts. The proposed CBZ sensor probe based on ternary oxide RuO₂/ZnO/TiO₂ NCs was developed with significant analytical parameters for practical application in monitoring the environmental pollutants of CBZs for the safety of environmental fields on a large scale.

Graphene takes concerned noteworthy consideration payable its distinctive thermal, optical as well as mechanical characteristics. There are several chemical methods are available for reduce graphene oxide (r-GO) towards graphene use by many reducing agent’s alike hydrazine hydrate and its derivatives. Nevertheless, they are highly explosive and emit harmful gases. Reduction of graphene oxide (GO) employing green approaches by way of plants consumes fascinated much devotion by reason of its competence, sustainable structures, and relatively low in price. Though, the crucial constituents in green extracts and their biological degradation determinations regarding GO continue quiet not well unstated. Now present work, the GO was reduced by capsicum annuum (CA) extract. The ideal circumstances for bio reduction existed at volume proportion of chili extract (10 g L−1) and GO (0.5 g L−1) solution aimed at 8 h at 80°C. The r-GO was considered with Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FESEM), X- Ray diffraction (XRD), Thermo gravimetric analysis/Differential thermal analysis (TGA/DTA), Brunauer-Emmett-Teller (BET), and zeta potential. Outcomes inveterate the oxygen-holding clusters in GO were well detached, development of topping coat on the exterior of r-GO, besides virtuous diffusion of r-GO in aquatic medium. The photo catalytic degradation of GO nano composite was 96% for methyl violet (MV) in 60 minutes.

This review article has described the recent publications in the development of Decoration of Graphene Oxide such as metals, metal oxides and their nanocomposites based materials. We anticipate this active field will continue growing rapidly, leading eventually to a variety of mature materials and devices that would benefit the society. Finally, the applications of composites are at their initial stages. They need to be studied systematically from both theoretical and experimental aspects.