Porous Co-MoS2@Cu2MoS4 three-dimensional nanoflowers via in situ sulfurization of Cu2O nanospheres for electrochemical hybrid capacitors

Engineering novel transition metal dichalcogenide (TMDC) materials with three-dimensional (3D) porous nanostructures have demonstrated exceptional electrochemical performance in energy storage due to their synergistic special morphological features and conductive metal ions. Herein, hetero-network-based MoS2@Cu2MoS4-210 (MS@CMS-210; obtained at 210 degrees C) 3D nanoflowers (NFs) and Co-nanoparticles-containing MS@CMS-210 (Co-MS@CMS-210) 3D NFs were prepared by a hydrothermal synthesis method without calcination. We used uniform Cu2O nanospheres (NSs) obtained via a co-precipitation method as a template to synthesize the hierarchical MS@CMS-210 3D NFs. The unique MS@CMS-210 3D NF morphology was obtained due to the in situ sulfurization effect of Cu2O NSs at the reaction temperature of 210 degrees C and further detailed growth process was explored. The electrochemical performances of Cu2O NSs, sulfurized MS@CMS products prepared at the reaction temperatures of 180, 190, 200, and 210 degrees C, and Co-MS@CMS-210 hetero-network-based electrodes were investigated. The Co-nanoparticles introduced into the optimized MS@CMS-210 3D NFs provided a higher specific surface area of 128.58m(2) g(-1), further exhibiting a greater specific capacity (220 mA h g(-1) at 1 A g(-1)) and enhanced cycling stability (similar to 96% retention at 10 A g(-1)) compared to the other electrodes. The better electrochemical results were obtained due to the developed rich electroactive sites and rapid redox reactions from the rational combination of Co-MS@CMS-210 3D NF morphology and conductive natured TMDC hybrid composite. Additionally, a pouch-type electrochemical hybrid capacitor (Co-MS@CMS-210//activated carbon) device was constructed and it provided maximum energy and power density values of 41.6 W h kg(-1) and 6240 W kg(-1), respectively, along with greater cycling stability. Finally, several portable electronics such as green/red light-emitting diodes and timer displays were successfully tested to demonstrate the practical utility of the device in the area of energy storage.

Automated summary

Novel transition metal dichalcogenide materials with three-dimensional porous nanostructures exhibit outstanding electrochemical performance. By synthesizing hierarchical nanoflowers and introducing Co nanoparticles, higher specific surface area and improved cycling stability were achieved, leading to better electrochemical results. A pouch-type electrochemical hybrid capacitor device constructed in the study demonstrated high energy and power density values, along with superior cycling stability, showcasing its practical utility in energy storage for portable electronics.