Facet engineering in Au nanoparticles buried in Cu2O nanocubes for enhanced catalytic degradation of rhodamine B and larvicidal application

Water systems around the world are significantly impacted by organic pollutants from industrial activities. In this study, we report a novel and promising approach utilizing a cost-effective and simple chemical co-precipitation method for the synthesis of Cu2O@Au nanocubes. The characterization of these nanocubes was conducted using various advanced techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL). These analyses revealed the formation of crystalline nanocube-structured catalyst, confirming their purity, chemical state, and electronic structure. The synthesized Cu2O@Au nanocubes, particularly with 5 % Au over Cu2O, showed the highest catalytic efficiency in degrading Rhodamine B (RhB), achieving about 99.6 % degradation in 7 min. The deposition of Au significantly enhanced the electron mobility, thereby increasing the catalytic efficiency of the catalyst. GC/MS analysis performed to identify the intermediates formed and a possible degradation pathway of RhB was proposed. In addition, the toxicity of intermediates also evaluated by ECOSAR software. Reusability tests were conducted to assess the consistency and practical application of Cu2O@Au-5 % nanocubes. The results indicated high stability and sustained catalytic performance over multiple cycles. Additionally, the multifunctional properties of the synthesized material were validated through larvicidal activity tests, demonstrating its potential for broader environmental applications. Overall, Cu2O@Au-5 % presents a highly efficient and versatile catalyst for environmental remediation and other practical applications, demonstrating significant potential for large-scale use. These findings underscore the promise of Cu2O@Au as a multifunctional catalyst, capable of delivering substantial advancements in both environmental and- human health domains.