Cerium oxide nanoparticles: sustainable synthesis and diverse applications in electrical properties, catalysis and biomedicine

This study presents an innovative and environmentally friendly approach for the synthesis of cerium oxide nanoparticles (CeO₂ NPs), characterized using advanced techniques such as FTIR, XRD, SEM, TEM and XPS. Notable spectral peaks at 457 cm⁻¹ and 1380 cm⁻¹ confirm the successful formation of CeO₂ NPs, with an average size of 5.72 nm and a spherical morphology revealed through XRD and SEM analysis. We explored the multifaceted applications of these synthesized NPs, particularly their impressive electrical properties and catalytic capabilities. The CeO₂ NPs demonstrated a remarkable role in synthesizing sulfides from thiols and bromoesters, which were further oxidized to sulfoxides with excellent yields using m-chloroperbenzoic acid (m-CPBA). Electrical property assessments revealed that the CeO₂ NPs exhibit insulating behavior at lower frequencies while transitioning to semiconducting characteristics at higher frequencies. Furthermore, we evaluated the cytotoxicity of the CeO₂ NPs on MCF-7 human breast cancer cells, alongside tests for biocompatibility through blood hemolysis. The NPs displayed a significant DPPH radical scavenging activity with an effective concentration of 242 μg/mL, and a safe hemolytic activity at levels below 2.5 mg/mL, indicating their potential as promising candidates in biomedical applications.