Biomass-based porous carbon with surface grown MXenes for high-performance electromagnetic absorption and supercapacitor validated from structural and charge changes

The development of new materials for electromagnetic wave absorption and energy storage has gained significant attention due to their widespread applications. This study introduces a novel approach to address the stacking issue of MXenes and enhance the electromagnetic shielding capabilities of porous carbon by combining them with jujube shell porous carbon. This composite material exhibits outstanding electromagnetic shielding properties and electrochemical energy storage performance. The addition of polar acetone enhances the interfacial interaction between the carbon matrix and Ti 3 C 2 Tx, resulting in a remarkable return loss of − 36.1 dB for AJSPC&Ti-A, signifying the absorption of 99.9% of incident electromagnetic waves. The three-dimensional (3D) porosity and two-dimensional (2D) laminar structure of the composite prolong the propagation of electromagnetic waves, leading to multiple reflection and scattering effects. Furthermore, the 3D porous structure provides abundant channels and active sites for the storage and transport of electrolyte ions. In electrochemical testing, AJSPC&Ti-A achieves a specific capacity of 156.1 F/g at 1 M Na 2 SO 4 and 0.5 A/g, surpassing the performance of alkaline electrolytes. In a symmetrical capacitor configuration, this composite demonstrates an energy density of 8.4 Wh/kg, accompanied by a power density of 193.0 W/kg. Density functional theory analysis reveals changes in the interface between porous carbon and Ti 3 C 2 Tx, attributed to electronegativity differences and increased spin density. These alterations manifest in the redistribution of charge density and uneven electron distribution. Additionally, the s and d orbitals contribute to the enhancement of density of states, promoting multiple polarization relaxation and charge transfer in AJSPC&Ti-A. This research introduces a new class of composites that exhibit dual functionality, offering efficient electromagnetic shielding and excellent electrochemical energy storage capabilities. Graphical Abstract