Experimental and theoretical exploration of bactericidal and photo-catalytical activities of hierarchically porous AuNRs@CuO nanocomposite

In this study, a novel binary nanocomposite consisting of CuO nanosheets functionalized with gold nanorods (AuNRs@CuO), was successfully prepared using a two-step synthetic procedure and further investigated via Density Functional Theory. The physicochemical properties of prepared nanomaterials were analysed using Fourier transform infrared spectroscopy, X-ray diffraction, Field emission scanning electron microscopy, High-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy confirming successful fabrication with improved surface properties. Experimental analyses, including antibacterial assays and morphological studies of bacterial cells demonstrates superior bactericidal properties of AuNRs@CuO nanocomposite compared to pristine CuO nanosheets. Furthermore, molecular docking score provide theoretical insights into the underlying mechanism governing the enhanced antibacterial activity, highlighting the favorable interaction with the bacterial cells. The synergistic effect of CuO nanosheets and AuNRs further improves the photocatalytic efficacy, culminating in a high-yield photocatalyst that achieves 98.7% degradation for Indigo carmine under Xenon lamp irradiation compared to 40.8% and 62.4% for AuNRs and CuO nanosheets alone. Improved charge separation and generation of H+ as major reactive oxygen species from the nanocomposite to Indigo carmine was revealed by radical scavenger activity and photoluminescence studies. After cycles of operation, the morphology and surface state of the photocatalyst remained unchanged, as investigated by FESEM and HRTEM analysis. The novelty of this study lies in the integration of AuNRs and CuO nanosheets as an efficient photocatalytic material for the remediation of toxic organic dyes in wastewater, presenting a promising advancement in sustainable water treatment technologies.