Polysiloxane microspheres encapsulated in carbon allotropes: A promising material for supercapacitor and carbon...

Recently, hierarchical porous materials have received tremendous attention in electrochemical supercapacitors and CO₂ adsorption. Both areas of application have a positive impact on global warming by reducing CO₂ emissions to the atmosphere. Herein, we synthesized new silica-based ceramic monoliths composed of polysiloxane microspheres sheathed by carbon allotropes (Graphene or MWCNT) and metal nanoparticles. The as-synthesized hybrid ceramics show a high specific surface area of 540 m² g^-1 with hierarchical micro-/meso-/macroporous structures. With the structural benefits, the obtained ceramics exhibits excellent performance in supercapacitors and for CO₂ adsorption as probed in this study. As an electrode material for supercapacitor, the hybrid ceramics delivered the specific capacitance of 93 F/g at 2 mV s^-1 in 0.5 M KOH electrolyte solution with a capacity retention of 88% after 50 cycles. Further, as a solid adsorbent, the hybrid ceramics shows the maximum CO₂ adsorption capacity of 2 mmol g^-1 at 100 kPa equilibrium pressure and 303 K, while maintaining 98% capacity retention after 10 cycles. Thus, the hybrid ceramics with its unusual properties make them a promising candidate for both, supercapacitors and CO₂ capture in the sheer physical adsorption process.