Efficient supercapacitor based on polymorphic structure of 1T″-Mo₆Te₆ nanoplates and few-atomic-layered 2H-MoTe₂: A layer by layer study on nickel foam

Te-based transitional metal dichalcogenides (TMDs) as supercapacitors are gaining substantial attention with a few reports. The integration of 1T′-Mo₆Te₆ nanoplates (NPs) into few-atomic-layered two dimensional (2D) 2H-MoTe₂ thin film has not been realized in supercapacitive studies. Herein, we demonstrate the growth of 1T′-Mo₆Te₆ NP/2H-MoTe₂ thin film polymorphic structure through metal organic chemical vapor deposition (MOCVD) on Si/SiO₂ and thereby, the successful transfer of these polymorphic structure on a flexible nickel (Ni) foam current collector by simple chemical etching protocol for high performance supercapacitors. A layer by layer study of the Mo₆Te₆/MoTe₂ polymorphic structure is carried out by varying the number of transfer layers on the Ni foam. The resultant supercapacitors demonstrate a three-fold enhancement in areal capacitance (1542 mFcm⁻² at 10 mVs⁻¹) compared to a single layer transferred electrode, together with remarkable electrochemical stability (96%) and high energy density (140.36 mWcm⁻² at 4 mA). These supercapacitors outperform the TMD-based (Te-based) supercapacitors presented in the past, demonstrating the high potential for their application in energy conversion devices.