Optimisation de l'efficacité de production d'hydrogène dans un système photochimique de stockage de l'énergie solaire

The efficiency of hydrogen production has been optimised as a function of pH and concentration of the different components of the Ru(bipy) 3 2+ /MV 2+ /EDTA/colloidal Pt model system irradiated by visible light (λ exc =453 nm). The optimum quantum yield Φ (1/2 H 2 )=0.171±0.20 is found for the following parameters: pH 5, Ru(bipy) 3 2+ 5.65×10 −5 M, MV 2+ 3×10 −3 M, EDTA 10 −1 M and colloidal Pt 1.92×10 − 5 M. Methyl viologen radical cation quantum yields have been determined under the same conditions but in the absence of Pt, and the obtained optimum value Φ (MV +. )=0.181±0.020 represents a limit for Φ (1/2 H 2 ). Hydrogen and MV +. formation yields are closely related (fig.) in the whole MV 2+ concentration range investigated which confirms a previous result where colloidal Pt was found to give an efficiency close to 100% Determination experimentale du PH et de la concentration des differents elements du systeme modele Ru(bipy) 3 2+ /MV 2+ /EDTA/Pt colloidal donnant une valeur optimale du rendement quantique de la formation d'hydrogene. Mesure dans les conditions optimales ainsi determinees du rendement quantique de formation du radical cation methyle viologene en l'absence de Pt