Controlled synthesis of Cu2O/Cu@SiO2 core-shell heterostructure spherical nanoparticles via direct current arc discharge driven by interfacial interactions of micro-droplets

Cu 2 O/Cu@SiO 2 core–shell nanoparticles were fabricated by a DC arc plasma process. • Differential interfacial interactions among molten droplets drive core–shell formation. • Interfacial tension is identified as the key factor controlling structural evolution. Cu@SiO 2 core-shell heterogenous nano particles (Cu@SiO 2 CSHNPs) demonstrate significant application advantages in catalysis and functional material modification. Direct current arc plasma technology holds considerable promise for the synthesis and industrialization of related materials due to its inherent advantages. However, issues such as the complex and unclear synthesis mechanism of the Metal@SiO 2 system via direct current arc plasma methods constrain its potential for structural and performance regulation. In this study, Cu 2 O/Cu@SiO 2 core-shell particles were in situ synthesized for the first time via DC arc process. Building upon this, morphological and compositional analysis of the products led to the innovative proposal of a formation mechanism for core-shell heterostructures based on differential interfacial interactions between micro-nano molten droplets. The experimental results reveal that differences in interfacial tension among micro/nanoscale molten droplets play a decisive role in governing the phase distribution and structural evolution of the products. This work provides a new perspective for understanding the formation of Metal@SiO 2 core–shell nanostructures under arc plasma conditions and offers theoretical guidance for the controllable synthesis of related heterogeneous nanomaterials.