One-Pot Synthesis of Tunable Crystalline Ni₃S₄@Amorphous MoS₂ Core/Shell Nanospheres for High-Performance Supercapacitors

Transition metal sulfides gain much attention as electrode materials for supercapacitors due to their rich redox chemistry and high electrical conductivity. Designing hierarchical nanostructures is an efficient approach to fully utilize merits of each component. In this work, amorphous MoS₂ is firstly demonstrated to show specific capacitance 1.6 times as that of the crystalline counterpart. Then, crystalline core@amorphous shell (Ni₃S₄@MoS₂) is prepared by a facile one-pot process. The diameter of the core and the thickness of the shell can be independently tuned. Taking advantages of flexible protection of amorphous shell and high capacitance of the conductive core, Ni₃S₄@amorphous MoS₂ nanospheres are tested as supercapacitor electrodes, which exhibit high specific capacitance of 1440.9 F g^-1 at 2 A g^-1 and a good capacitance retention of 90.7% after 3000 cycles at 10 A g^-1. This design of crystalline core@amorphous shell architecture may open up new strategies for synthesizing promising electrode materials for supercapacitors. The nanoarchitecture of crystalline core/amorphous shell particles is proposed for enhanced capacitance and cyclability for supercapacitor electrodes. Driven by the concept, uniform transition metal sulfides core/amorphous shell nanospheres with tunable sizes are produced by a facile one-pot solution-based method. The resulting hybrids show great potential for supercapacitor applications.