Facile synthesis of cross-linked Ag–CdS nanoshell morphology for highly efficient photocatalytic activity

Abstract

The increasing water pollution due to toxic dyes is a matter of concern from an environmental point of view because it has a long-term impact on animal and plant life. Photocatalysts act as a saviour that can degrade these organic molecules under visible and/or solar light. However, achieving enhanced luminescence performance, reusability, and high stability is challenging with affordable photocatalysts. In this work, a Ag–CdS composite nanomaterial with a unique cross-linked shell morphology was synthesized via a simple and cost-effective chemical method. In a wet chemical synthesis method, Na₂S (sodium sulfide) releases S²⁻ ions, which react with Cd²⁺ ions in the presence of Ag nanoparticles and capping agent trisodium citrate (TSC), neutralizing the possibilities of over-aggregation. Therefore, the controlled growth of the Ag–CdS composite resembled a cross-linked structure comprising shells of CdS nanoparticles with Ag in the centre. The composition and morphology of obtained heterostructures were investigated by XRD (X-ray diffraction), XPS (X-ray photoelectron spectroscopy), and electron microscopy. The photoelectrochemical and photoluminescence behaviour was examined, which explained the trend of catalytic properties. The photocatalytic behaviour was finally observed with Rhodamine 6G (R6G) and methylene blue (MB), which are considered among the most resistant dyes and showed significant improvement of catalytic response over the previously reported Ag–CdS nanocomposites with ∼98% and 94% degradation after 105 min and 120 min, respectively.