Preparation of porous layered molybdenum selenide-graphene composites on Ni foam for high-performance supercapacitor and electrochemical sensing

Graphene and the flexible Ni foam substrate are used in a facile hydrothermal process to control the formation of MoSe2-graphene composites. The effects of the content of graphene on the structure of MoSe2-graphene composites are investigated and the results indicate a suitable proportion of MoSe2 and graphene (7:1) is more beneficial to the charge transport and ion transfer owing to formation of unique porous layered structure. In this composite, abundant graphene nanosheets cover on the surface and interspace of MoSe2 bars homogeneously, leading to large specific surface area and plenty of macropores. As the electrode material of supercapacitors, the composites display a high specific capacitance of 1422 F g−1 and retain the specific capacitance of 100.7% after 1500 cycles. As expected, after charged at a current density of 5 A g−1, the composites can light up a miniature bulb for more than 70 seconds. Moreover, the as-prepared materials exhibit a good catalytic activity toward the electrochemical oxidation of dopamine with a linear range of 0.01-10 μM and the detection limit of 1.0 nM in terms of the role of signal to noise ratio of 3:1 (S/N = 3). These results indicate that the porous layered MoSe2-graphene composite in situ prepared on Ni foam can be applied for high-performance supercapacitors and electrochemical sensors.