Active-Site-Rich 1T-Phase CoMoSe2 Integrated Graphene Oxide Nanocomposite as an Efficient Electrocatalyst for Electrochemical Sensor and Energy Storage Applications.

The presence of defect/distortion on layered structure of metal chalcogenides facilitate the higher electronic conductivity and electrocatalytic activity. In this work, we have successfully synthesized Co-doped MoSe2(CoMoSe2, Co2MoSe2, Co3MoSe2, and Co4MoSe2) in 1T phase crystal structure by using hydrothermal technique and integrated with graphene oxide (GO). Various analytical techniques such as TEM, STEM, FESEM, XRD, RAMAN, EDX, ICP, and XPS confirmed the formation of 1T phase and defective sites on Co-doped MoSe2. Consequently, the relevant electrochemical studies were followed and reported the significant enhancement in electrocatalytic activity of MoSe2 due to the Co doping and GO hybridization. The proposed GO@CoMoSe2 electrocatalyst was developed to an electrode material for electrochemical sensor and supercapacitor applications. As expected, the GO@CoMoSe2 modified glassy carbon electrode exhibited an excellent electrocatalytic activity toward the sensing of Metol (LOD, 0.009 μM; sensitivity, 2.397 μA μM-1 cm-2). Meanwhile, GO@CoMoSe2-coated nickel foam (NF) achieved feasible specific capacity (431.47 C g-1). In addition, the GO@CoMoSe2//AC asymmetric device exhibited the feasible energy density of 58.32 W h kg-1 at power density of 1800.25 W kg-1. Thus, we concluded that the Co doping and GO hybridization with MoSe2 provide the interesting idea to find out the excellent electrocatalysts with improved electrochemical performances toward the sensing and battery type supercapacitor applications.