Remarkably improving dielectric response of polymer/hybrid ceramic composites based on 0D/2D-stacked CuO/V2C MXene heterojunction

Highlights: • Strong synergy between V₂C MXene and CuO ceramics. • Improved comprehensive electrical traits in novel material system. • Electron polarization mechanism at V₂C/CuO heterojunction. High dielectric response and electric insulation are desired in high-energy-density polymer/ceramic composites. Low dielectric response is found in polymer composites with semiconductors. To balance a high dielectric constant and breakdown strength, in this work, the polymer-based composites with de novo synthesized V₂C MXene-CuO hybrid-particles were fabricated. High dielectric response of composites was attributed to strong electron polarization at ceramic/ceramic heterojunction. High insulation was ascribed to fluorine-induced electron-trap effect. The first principle calculations verified the electron-transfer mechanism at V₂C/CuO van der Waals heterojunctions. Compared with polymer/CuO binary composites, polymer/V₂C-CuO ternary composites exhibited the improved comprehensive electric properties (remarkably improved dielectric response and slightly damaged insulation). Ternary composite with 10 wt% V₂C-CuO showed a high dielectric constant of 89, low dielectric loss of 0.23, low conductivity of 6.8 × 10⁻⁷ S m⁻¹ at 100 Hz and high breakdown strength of 204 MV m⁻¹. This study might enable a facile preparation of cutting-edge nanocomposite dielectrics.