Light Induced Hydrogen Production From Ethanolic Aqueous Solutions Sensitizzed By 2,4-Dimetboxy Benzylidene-2- Hydroxy Aniline And Some of Its Metal Complexes

Hydrogen productions were achieved by irradiating ethanolic aqueous solutions (20%. v/v) containing mixtures of the ligand 2,4- dimethoxybenzylidene-2-hydroxy aniline (HL) or one of its complexes (ML2) with the fo llowing divalent ions: Mn (II), Fccn), Co(JI)، Ni(II), Cu(JI) and Zn (Il), as photosensi1izer-s, methyl viologen (MV2-) as electro11 acceptor, ethylene diamine tetraacetic acid disodium saJt (EDT A) as a sacrificial electron donor. in presence of platinum poly (vinyl alcohol) (Pt-PVA) or platinized Ti02 (Pt!Ti02). (200 and 45 microq) as reduction catalysts, using; white light fr0m 250 W xenon arc lamp at room temperature 25±2 °C. Oxidation Potentials of the ligand and its complexes were determined by cycl ic voltammetry. The efficiency of the photoreduction of MV+² and hydrogen production by HL and metal .complexes was mainly dependant on pH, type and pardcle si)le of catalyst, as well as 111eLal iQn in case of ML2. Best performances were recorded by the free ligand.