New hybrid material based on silica-immobilised conjugated beta-ketoenol-bipyridine receptor and its excellent Cu(II) adsorption capacity

A new hybrid material based adsorbent for the efficient elimination of Cu(II) was synthesized by the immobilization of a new conjugated b-ketoenol-bipyridine ligand receptor onto a silica matrix. The analysis of its surface chemistry was evaluated using a set of suitable techniques. Adsorption studies highlight its surface properties for the excellent removal of Cu2+ (131.82 mg g1) from aqueous solutions using FAAS. The effect of various parameters, such as pH, initial metal concentration, temperature, competitive extraction, thermodynamics and kinetics, on the adsorption of several heavy metals was investigated via metal extraction from real water samples. The adsorption efficiency increases with an increase in pH and follows pseudo-second-order kinetics. Adsorption is rapid, as evidenced by the achievement of equilibrium within 25 min. Adsorption equilibrium data were well fitted to the Langmuir isotherm model and the maximum monolayer adsorption capacity for Cu2+, Zn2+, Cd2+, and Pb2+ was 131.82, 110, 90.75 and 79.71 mg g1, respectively. The removal of metals onto the new adsorbent is endothermic and spontaneous in nature. The adsorbent presents high selectivity for Cu2+, in competitive mode, compared to other metals and recent literature reports

Keto-enol heterocycles as new compounds of corrosion inhibitors for carbon steel in 1 M HCl: weight loss, electrochemical and quantum chemical investigation

International audienceIn this paper, the effect of Keto-enol derivatives namely (Z)-3-hydroxy-1-(pyridin-2-yl)but-2-en-1-one (KE-1) and (Z)-1-(1,5-dimethyl-1H-pyrazol-3-yl)-3-hydroxy-3-(pyridin-2-yl)prop-2-en-1-one (KE-2)on the inhibition of carbon steel (CS) corrosion in 1 M HCl has been studied using weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and quantum chemical study. Weight loss measurements indicate that these compounds reduce the corrosion rate of carbon steel in acidic solution and the inhibition effect increases with the inhibitors concentration but decreases with temperature. The electrochemical polarization study revealed that the tested Keto-enol derivatives are mixed type. EIS show that the KE-1 and KE-2 form an adsorptive layer on the metallic surface. The adsorption of the KEs on the carbon steel surface obeys the Langmuir adsorption isotherm. The results of quantum chemical calculations and Monte Carlo simulation studies are in good agreement with experimental results