Covalent attachment of Ni-2,3-pyrazine dicarboxylic acid onto gold nanoparticle gold electrode modified with penicillamine- CdS quantum dots for electrocatalytic oxidation and determination of urea

Facile fabrication of bifunctional SnO-NiO heteromixture for efficient electrocatalytic urea and water oxidation in urea-rich waste water

Heterostructured transition metal oxide hybrid have more attention in energy saving and environmental related field due to their higher electro-catalytic activity. In this work, we demonstrated SnO decorated with NiO nanocrystal electrocatalyst is successfully synthesized through solvothermal method and well characterized by scanning electron microscope, transmission electron microscope, X-ray diffraction and X-ray photoelectron spectroscopy. Physical characterizations confirm that spherical shape of SnO nanoparticles are homogeneously dispersed on the surface of NiO. The kinetic study of catalytic performance towards urea oxidation reaction were measured by liner sweep voltammetry and chronoamprometry. As proposed catalyst to facilitate the rate of urea oxidation reaction can increase by SnO doped NiO catalyst. The urea oxidation on SnO-NiO nanostructured modified electrode exhibits lower onset potential of 1.12 V and enhancement of current with tafel slope of 150 mV dec^-1. The obtained results demonstrated the synthesized SnO-NiO anode material could be promising electrode for urea-rich containing wastewater remediation and hydrogen production from wastewater.

Electrochemical sensing of 2-methyl-4, 6-dinitrophenol by nanomagnetic core shell linked to carbon nanotube modified glassy carbon electrode

Electrochemical behavior and sensing of 2-methyl-4, 6-dinitrophenol as an herbicide has been investigated by cyclic voltammetry (CV) and square wave voltammetry (SWV). We have synthesized a cefazolin (CEF) immobilized nanomagnetic core-shell (Fe₃O₄@SiO₂-(CH₂)₃-CEF) and attached it on the modified glassy carbon electrode (GCE/MWCNT) through electrostatic adsorption (GCE/MWCNT/CEF-SiO₂@Fe₃O₄). 2-Methyl-4, 6-dinitrophenol has an oxidation peak that is related to the formation of nitrosamine from hydroxylamine species. This peak was applied for quantifying determination of 2-methyl-4, 6-dinitrophenol. The electrochemical oxidation involves two electron transfers accompanied by two protons. The electrochemical process was controlled by adsorption. The good agreement between the obtained computational studies and the experimental results has demonstrated that outer sphere electron transfer occurred on modified electrode. The new electrochemical sensor was applied to determination of 2-methyl-4, 6-dinitrophenol by SWV in the range of 1.0 × 10^-10 to 1.5 × 10^-7 M with a detection limit of 0.1 nM. The proposed sensor was applied for determination of 2-methyl-4, 6-dinitrophenol in water samples.

Ultrathin nickel-metal–organic framework nanobelt based electrochemical sensor for the determination of urea in human body fluids

Ni-MOF ultrathin nanobelts in alkaline media can be used as an efficient catalyst for urea electrooxidation.