Pumpkin-like MoP-MoS2@Aspergillus niger spore-derived N-doped carbon heterostructure for enhanced potassium storage

Biomass-derived carbon materials are widely applied in the energy storage and conversion fields due to their rich sources, low price and environmental friendliness. Herein, a unique pumpkin-like MoP-MoS2@Aspergillus niger spore-derived N-doped carbon (SNC) composite has been prepared via a simple hydrothermal and subsequent phosphorization process. Interestingly, the resulting MoP-MoS2@SNC well inherits the pristine morphology of spore carbon, similar to the natural pumpkin, with hollow interiors and uneven protrusions on the surface. The special structure allows it to have sufficient space to fully contact the electrolyte and greatly reduces the ion transport distance. The theory calculations further demonstrate that the formed MoP-MoS2 heterostructure can enhance the adsorption of K ions and electronic couplings. With these unique advantages, the MoP-MoS2@SNC anode for potassium storage shows a high reversible capability of 286.2 mAh g−1 at 100 mA g−1 after 100 cycles and superior rate performance. The enhanced electrochemical performance is mainly related to the unique pumpkin-like morphology of SNC and the construction of MoP-MoS2 heterostructure, as well as their perfect coupling. This study provides a feasible design idea for developing green, low-cost, and high-performance electrode materials for next-generation energy storage.