Synergistic multi-functional N-doped carbon Nanocage@CNT/ZnMn2O4/Ti3C2 MXene: Powering battery, supercapacitor, and catalyzing hydrogen evolution

This study presents a novel approach to enhance the electrochemical capabilities of 3D pyrolytic carbon for energy applications. Using a chemical blowing technique, highly conductive carbon nanotubes (CNTs) are embedded within a 3D N-doped carbon nanocage (NCN). This integration involves an additional carbon source during Ni(NO3)2 induced polymer blowing, leveraging the dual role of Ni(NO3)2 in polymer expansion and catalyzing CNT growth. Our research merges ZnMnO4/Ti3C2 with high-capacity N-Doped Carbon Nanocage@CNT (NCN/CNT@ZnMnO4/Ti3C2) to amplify electrochemical performance. The NCN/CNT@ZnMnO4/Ti3C2 showed specific capacitance of 1843 Cg-1 at 1.0 Ag-1, attributed to augmented electrical conductivity and charge storage characteristics. The supercapattery configuration maintains a specific capacitance of 195 Cg-1 at 1.0 Ag-1, cyclic stability of 95% over 18,000 cycles, and a power density of 1145 W-kg−1 at an energy density of 67 Wh-kg−1. In HER applications, NCN/CNT@ZnMnO4/Ti3C2 demonstrates a lower Tafel slope of 56.41 mV-dec−1, signifying a significant advance in high-performance supercapacitors.