A new ternary ruthenium(III) complex with 1,3-bis(salicylideneamino) propan-2-ol and 3-picolylamine: Synthesis, characterization, density functional theory and preparation of electrochemical sensor for nitrite analysis.

International audienceA novel electrochem. sensor based on graphite (G) functionalised with a new ternary ruthenium(III) complex was developed and applied to detect nitrite in aq. soln. The Ru(III) complex was synthesized using 1,3-bis(salicylideneamino) propan-2-ol polydentate Schiff base (BSAP) and 3-Picolylamine (PLA), and was characterized by elemental anal., Fourier transform IR spectroscopy (FT-IR), UV-visible spectrophotometry (UV-Visible), gradient-assisted hetero nuclear single quantum coherence spectroscopy (gHSQC) and cyclic voltammetry technique. In addn., the structure of the synthesized complex was optimized using d. functional theory (DFT). The results showed that the ternary Ru(III)-BSAP-PLA complex was formed and the adapted structure was an tetrahedral geometry.The electrochem. behavior of nitrite at the sensor prepd. using G/Ru(III)-BSAP-PLA composite shows that the evaluated electron transfer coeff. (α = 0.83) indicates a very significant electrocatalytic mechanism for oxidn. of nitrite in the presence of the Ru(III)-BSAP-PLA complex.Comparing to other published works, the sensor developed using G/Ru(III)-BSAP-PLA exhibited low limit of detection (LOD = 1.81 μM) around pH = 7. [on SciFinder(R)

Structural and electrochemical characterizations of Bi12CoO20 sillenite crystals: degradation and reduction of organic and inorganic pollutants

International audienceThe present contribution is to synthesize and characterize a new material photocatalyst. It also explores the possibility of using it to remove organic and inorganic pollutants in water. In this context, the sillenite Bi12CoO20 (BCO) in pure phase was synthesized by the combustion sol-gel method. The phase was identified by X-ray diffraction (XRD) then it was refined in the cubic symmetry in the space group (I23 N degrees 197) using the Rietveld refinement method; the lattice constant was accurately determined. A direct optical bandgap of 2.56 eV was evaluated using the UV-Visible diffuse reflectance. The electrochemical properties were investigated for the first time. A flat band potential of E-fb = 0.62 V-SCE was found with a p-type character; the hole density N-d = 54.2 x 10(17) cm(-3) extends the depletion width at 27 nm. The photocatalytic activity of BCO nanoparticles was tested to eliminate organic and inorganic pollutants namely the Basic red 46 (BR46) and hexavalent chromium Cr(VI). An acceptable rate was observed within 3 h for both contaminants

Visible-Light Photoreforming of Biomass Derivatives through MBi2O4-P25 Heterostructures: Study of the Influence of Metals (M = Cu, Ni, Zn, Co)

In this work, MBi2O4-P25 (M = Cu, Ni, Co, Zn) composites are successfully synthesized by a simple ball milling method by varying some parameters (rotation speed, rotation time, metal/TiO2 ratio) to optimize the preparation conditions. The noble metal-free TiO2-based photocatalysts are used to carry out the partial oxidation of glucose and glycerol with the simultaneous H2 production under simulated solar light irradiation. Starting from glucose, 2.6 mmol of H2 are obtained with a conversion of 34%, along with arabinose, formic acid and gluconic acid as main intermediates. By using glycerol, 3.2 mmol of H2 are produced, with 17% conversion and the production of dihydroxyacetone and glycolic acid. The composites exhibit higher activity than pure P25 and CuBi2O4 (CBO). The produced H2 amount is comparable to that reported in the literature by using Pt–TiO2 photocatalysts. This study offers a paradigm for the future design of bifunctional photocatalysts for simultaneous noble metal-free H2 production and biomass valorization under environmentally friendly conditions with a possible scale up of the process