Effect of photodeposition of nickel on the photocatalytic, photoelectrochemical and surface properties of CdS

Abstract

<em>In situ </em>deposition of ferromagnetic metals (Fe, Co and Ni) increases photocatalytic activity and also avoids the aerial oxidation of the metals. The deposition of sulphides of Fe, Co and Ni also enhances the photocatalytic activity of CdS. Effect of photodeposition of nickel on the photocatalytic activity of CdS for decomposition of aqueous sulphide has also been studied and compared with that of <em>in situ </em>photodeposition of Fe, Co, Rh and Pd. The following order of activity is observed: Rh > Pd > > Co > Ni - Fe. Apart from Ni⁰, the various Ni - O species which are formed by the aerial oxidation of Ni⁰ have been identified by XPS studies of the Ni/CdS surface. Phctodeposition of Ni increases the photocatalytic activity and the photostability of CdS. A mechanism for the photocatalytic decomposition of aqueous sulphide has been proposed. Photodeposition of Ni decreases the photocorrosion of CdS, photovoltage and photocurrent of the PEC cell and also shifts the photocurrent onset potential to a more positive value.