Increase of antimicrobial and photocatalytic properties of silver-doped PbS obtained by sonochemical method

Abstract

In this work, pure PbS powders doped with silver were obtained in the proportions of 1, 2, 4 and 8 mol% by sonochemical method. Powders were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), UV–Vis spectroscopy (UV–Vis) and EPR analysis. The photocatalytic properties were estimated by degradation of methylene blue dye. The antimicrobial properties were studied by the formation of inhibition halos against Escherichia coli and Staphylococcus aureus bacteria and Candida albicans yeast. XRD patterns show that PbS, with a cubic structure, was obtained without the formation of secondary phases. FE-SEM analysis indicates loss of the cubic aspect of PbS samples as the Ag+ concentration increases and particle size reduces. The defects generated by the substitution of Pb2+ by Ag+ increase the photocatalytic activity, where PbS and P8A samples reduced by 25% and 68%, respectively, the MB concentration and significantly increased the antimicrobial activity against E. coli and S. aureus bacteria and C. albicans yeast.