Laser-Processed 2D Germanane on Graphene for Organohydrogel-Based Zinc-Ion Hybrid Capacitors

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Two-dimensional (2D) materials like silicene and germanene are gaining attention.
• Functionalized germanene (HGe/MGe) shows potential but lacks electrochemical studies for zinc ion storage.
• Limited electrical conductivity in layered germanane hinders charge transfer kinetics.

Purpose of the Study:

• To synthesize and characterize 2D HGe/MGe sheets decorated on laser-induced graphene (LIG).
• To evaluate the electrochemical performance of HGe/MGe-decorated LIG as a cathode for zinc ion hybrid capacitors (ZHCs).
• To investigate the zinc ion adsorption sites using experimental and theoretical methods.

Main Methods:

• A single-step, facile approach for in situ decoration of 2D HGe/MGe sheets over LIG using a pulsed laser.
• Morphological, chemical, and electrochemical characterization of the synthesized materials.
• Testing ZHC performance in aqueous electrolyte and polyacrylamide organohydrogel.
• Density functional theory (DFT) calculations for adsorption analysis.

Main Results:

• HGe/MGe-decorated LIG was successfully synthesized.
• HGe-decorated LIG achieved a notable Zn²⁺ storage capacity of 104 F g^-1 at 0.25 A g^-1 in aqueous electrolyte.
• MGe-decorated LIG demonstrated impressive cyclic stability with 83% capacity retention after 12,000 cycles.
• DFT calculations confirmed favorable Zn adsorption sites on MGe and HGe networks.

Conclusions:

• The study demonstrates the successful application of 2D functionalized germanane materials in zinc ion hybrid capacitors.
• The developed materials offer promising electrochemical performance, including capacity and cyclic stability.
• The findings highlight the potential of functionalized germanane for advanced energy storage applications, with possibilities for further tuning via various functional groups.