Hollow Co-Mo-Se nanosheet arrays derived from metal-organic framework for high-performance supercapacitors

摘要

Developing novel materials with rational structures and excellent electrical conductivity is vitally important for energy storage devices. Herein, hollow cobalt molybdenum selenide (Co-Mo-Se) nanosheet arrays are fabricated via a self-sacrificing template method and selenization process, where cobalt-organic framework serves as the template. Benefiting from unique hollow nanoarrays structure, the Co-Mo-Se electrode offers rich electroactive sites, large accessible regions for electrolyte, and short ions diffusion pathways. Additionally, it is observed that the Co-Mo-Se possesses a low charge transfer resistance owing to the intrinsic metallicity. As a result, the Co-Mo-Se electrode exhibits favorable energy storage properties, including high capacity (221.7 mAh g(-1)), good rate property, and outstanding stability (95% after 8000 cycles). More importantly, the assembled Co-Mo-Se//active carbon (AC) achieves high energy density (44.7 Wh kg(-1)) and remarkable durability. Notably, two hybrid devices connected in series successfully power an electronic watch for 70 min, demonstrating its practical applicability. These results indicate that the synthesized hollow Co-Mo-Se nanosheet arrays have promising applications as electrode materials for high-performance energy storage devices.