Green synthesis of multifunctional from cinnamon (cinnamomum verum) extract-functionalised CdS nanoparticles for In-vitro biomedical, photocatalytic degradation and photoelectrochemical applications

Cadmium sulphide nanoparticles (CdS NPs), renowned for their tuneable bandgap, exhibit significant potential for photochemical applications. A simple, green, and cost-effective synthesis approach is quite desirable to harness their full potential. With this prospect, we present the green synthesis of CdS NPs using cinnamon extract which is rich in polyphenols and flavonoids, as a reducing and stabilizing agent. The as-synthesized NPs were characterized with the aid of diverse characterization techniques. The study also attempts to understand the role of CdS NPs as photocatalytic material for methylene blue (MB) dye degradation in both UV irradiation and natural sunlight. Notably, 91% degradation was achieved within 90 minutes under UV light in a self-fabricated photoreactor setup, and 70 minutes under direct sunlight. Tauc plot also revealed that the catalyst promoted an indirect electron transfer pathway. Further, the semiconductor properties were evaluated using photoelectrochemical (PEC) studies, demonstrating charge transport dynamics. Additionally, the cytotoxicity of the NPs was also explored using in vitro investigations on human breast cancer cell line, revealing promising anticancer properties. Biocompatibility test on normal cells, and antibacterial assays were also studies. This comprehensive investigation underscores the applicability of green-synthesised CdS NPs in diverse field.