In-situ synthesis of Au–CdS plasmonic photocatalyst by continuous spray pyrolysis and its visible light photocatalysis

Abstract

Surfactant free Au–CdS hybrid plasmonic nanoparticles have been synthesized in-situ by using simple inexpensive continuous spray pyrolysis (CoSP) technique with the varying Au fraction. In-situ grown gold metal nanoparticles with controlled Au cluster size from 10 to 30nm in CdS matrix were obtained from this process. The surface plasmon band of Au nanoparticles in CdS appeared at λmax∼620nm and reveal red shifted at λmax∼655nm as Au loading increases. The CoSP prepared Au–CdS plasmonic nanoparticles have been found to show color tuning, enhancement in the absorption/extinction and PL quenching properties in the Vis- and NIR regions. Photodegradation of methylene blue (MB) dye under visible light was used to evaluate the performance of these CoSP made Au–CdS NPs with varying Au loading. The MB photodegradation efficiency was optimal (90%) for minimal Au loading of 0.15mM which is 26% higher than pure CdS nanoparticles. The performance of CoSP prepared nanoparticles was also confirmed degradation study of by rhodamine B (RhB) dye.