Mesoporous SnO₂ Nanostructures of Ultrahigh Surface Areas by Novel Anodization

Here we report a novel type of hierarchical mesoporous SnO₂ nanostructures fabricated by a facile anodization method in a novel electrolyte system (an ethylene glycol solution of H₂C₂O₄/NH₄F) followed by thermal annealing at a low temperature. The SnO₂ nanostructures thus obtained feature highly porous nanosheets with mesoporous pores well below 10 nm, enabling a remarkably high surface area of 202.8 m²/g which represents one of the highest values reported to date on SnO₂ nanostructures. The formation of this novel type of SnO₂ nanostructures is ascribed to an interesting self-assembly mechanism of the anodic tin oxalate, which was found to be heavily impacted by the anodization voltage and water content in the electrolyte. The electrochemical measurements of the mesoporous SnO₂ nanostructures indicate their promising applications as lithium-ion battery and supercapacitor electrode materials.