MnO_2@SnO_2 core-shell heterostructured nanorods for supercapacitors

摘要

A facile, low-cost synthesis of MnO_2@SnO_2 core-shell heterostructured nanorods with superior super-capacitance is proposed. The synthesis involves sensitizing MnO_2 nanorods with an aqueous SnCl_2 solution to ensure the formation of a thin, uniform, and complete shell layer. The SnO_2 coatings have rough surfaces and their thickness is about 18 nm. The MnO_2@SnO_2 composites have a specific capacitance of 367.5 F/g at 50 mV/s in 1 M Na_2SO_4, which is about four and six times of the pure MnO_2 nanorods and SnO_2 products. Meanwhile, they have 91.3% capacitance retention over 2000 cycles, which is much better than pure MnO_2 nanorods. The remarkable performances with a low-cost imply that they have potential for supercapacitors applications.