One-step solvothermal synthesis of different morphologies CuS nanosheets compared as supercapacitor electrode materials

• CuS nanosheets are synthesized by hydrothermal method assisted with or without surfactants.
• Supercapacitor electrode based on CuS nanosheets is fabricated.
• Microstructures and electrochemical properties of the electrodes are evaluated.
• CuS prepared without additive exhibits high specific capacitance and good cycling stability.

Layered-structure materials are quite promising ones for the next generation high-performance electrochemical supercapacitors. In this work, copper sulfide (CuS) with different morphologies are successfully synthesized via a simple one-step solvothermal method. Various hierarchical CuSs are fabricated with or without surfactants (cetyltrimethylammonium bromide (CuS-CTAB) and sodium dodecylbenzene sulfonate (CuS-SDBS)) as subsidiaries. The results show the electrochemical performance of CuS prepared without surfactant is superior than that assisted with surfactant. The as-obtained CuS nanosheets have pseudocapacitive characteristic and exhibit a high specific capacitance of 833.3 F g−1 at a current density of 1 A g−1, compared to 378.9 F g−1 for CuS-CTAB and 232.4 F g−1 for CuS-SDBS. In addition, the CuS nanosheets show better cycle property than CuS-CTAB and CuS-SDBS. The better electrochemical characteristics performances are owing to the thin CuS layer, which provides unique architecture facilitating charge transport and electrolyte diffusion.