1. Laboratory of Materials & Catalysis, Faculty of Sciences, Djillali Liabès University, Site I, B.P. 89, Sidi Bel-Abbès 22000, Algeria, Tel. ; Fax:
2. Departamento de Química Física, Instituto Universitario de Materiales, Universidad de Alicante, Apartado 99, Alicante 03080, Spain
3. Laboratory of Catalysis and Corrosion of Materials, Faculty of Sciences, University Chouaïb Doukkali, El Jadida, Morocco