Evaluation of CuS nanorods surface interaction with Cd²⁺ ions, Methyl Orange and microbes for clean water management

In this study, we report an eco-friendly approach for synthesizing CuS nanorods using aqueous extract of Syzygium cumini seeds as a sustainable alternative. The formation of CuS nanorods were confirmed with UV-Vis, SEM and TEM investigations and were found to be around 6-10 nm in length with hexagonal phase. The adsorption of Cd²⁺ ions onto CuS nanorods was optimized using Box-Behnken Design. The adsorption capacity of CuS nanorods towards Cd²⁺ ions was calculated to be 266.5 mg g^- 1. Based on the error analysis, the Langmuir isotherm and pseudo second order kinetic models were best applicable for the obtained data. Activation energy of 24.73 kJ mol^- 1 from Arrhenius equation suggests the physical adsorption of Cd²⁺ ions by CuS nanorods. A maximum MO degradation was achieved within 120 min with first order kinetics explaining the degradation process. The CuS nanorods were explored for antimicrobial activity against E. coli and S. aureus and the zone of inhibitions were high due to the rod shaped CuS nanomaterial with ROS generation being mechanism of activity. These results highlight the ability of the CuS nanorods synthesised in this study in wastewater treatment with microbial activity making it a sustainable material for clean water management.