High gas-sensor and supercapacitor performance of porous Co3O4 ultrathin nanosheets

Abstract

Highly porous Co₃O₄ ultrathin nanosheets were synthesized by a facile two-step approach, including a hydrothermal technique without any surfactant and subsequent calcination of the precursor. The as-synthesized materials belonged to the cubic spinel Co₃O₄ phase according to X-ray diffraction and transmission electron microscopy; and Brunauer–Emmett–Teller measurements showed that the surface area was about 97.2 m² g⁻¹. Owing to the unique porous ultrathin structural features, the pseudocapacitor capacitance of porous nanosheets was as high as 378 F g⁻¹ at a current density of 1 A g⁻¹, and the cycling stability remained about 78.5% after 2000 cycles. In addition, the porous Co₃O₄ ultrathin nanosheets based sensor exhibited good sensitivity and selectivity to ethanol. These results demonstrated that the porous Co₃O₄ ultrathin nanosheets were excellent candidates for electrochemical supercapacitor devices and ideal gas-sensor to ethanol.