The s ynergism between nanostruc tured Cd S and Cd O in photo catalytic degradation of methyle ne blue

Sulphide photocatalysts, which have narr ow band ga ps and valence bands at relatively negative potentials compared to oxides, are good candidates for visible light-drive nphotocatalysts. Among the avail able sulphide semicondu ctors nanosized CdS is an interestin g photocatalyst material, since it h as a narrow band gap (۲.۴ eV). However, the photocatalytic properties of CdS are limited as a consequence of its photocorrosion under visible light irradiatio n [۱]. Nevertheless, the re are strate gies for red ucing photo corrosion and increasin g the phot ocatalyst efficiency of C dS, which o ne of them is combining the CdS semiconductor with oth er semiconductors with different energy. The o ptoelectronic properties of CdO ma ke these materials interesting as se miconductor s for combining with C dS. CdO ex hibits a ban d gap in t he interval ۲.۲–۲.۴ eV with high tr ansmittance and very low resistance. There are interestin g results showing the in crease in C dS activity for samples mixed with CdO [۲, ۳]. In this wor k, we have d eveloped a simple route for prepar ing of CdO-CdS nanoco mposites an d studied photocatalytic degradatio n of methylene blue using the prep ared nanocomposites.

Keywords:

Nanostructure , cad mium oxide , cadmium s ulfide , photo catalyst , me thylene blu e