Design and preparation of MoO 2 /MoS 2 as negative electrode materials for supercapacitors

In this work, the MoO2/MoS2 composite material with unique flower-like microsphere structure is prepared via a facile hydrothermal synthesis. Furthermore, the composite material is served as negative electrode for supercapacitors. Ascribe to the synergistic effect, including the improved electron conductivity, the coexistence of two energy storage mechanisms, and a stable flower-like microsphere structure, the as-fabricated MoO2/MoS2 exhibits a high specific capacitance of 433.3 F g−1 at a scan rate of 5 mV s−1 and a superior cycling stability of 84.41% retention after 5000 cycles compared to that of pure MoO2 (33.33% retention after 2000 cycles) and pure MoS2 (58.33% retention after 2000 cycles) at a current density of 1 A g−1 in 1 M Na2SO4 electrolyte. Moreover, we also synthesize a series of MoO2/MoS2 electrode materials, which are used to further illustrate the synergistic effect in MoO2/MoS2 composite materials. This work signifies such materials as negative electrodes exhibit bright application prospects for supercapacitors. Keywords: Molybdenum dioxide, Molybdenum disulfide, Negative electrode, Synergistic effect, Supercapacitors