MoSn2Se4-decorated MXene/functionalized RGO nanohybrid for ultrastable supercapacitor and oxygen evolution catalyst

Abstract

Multifunctional MXene-based electrode with good electrocatalytic performance in oxygen evolution reaction as well as superior supercapacitor performance is rare so far. In this study, Mo and/or Sn selenides were grown on a template of MXene (Ti3C2Tx)/amine functionalized reduced graphene oxide (NH2-RGO) binary composite material via facile hydrothermal method. The presence of Mo and Sn metal centers has a crucial significance to increase the reactive sites over Ti3C2Tx/NH2-RGO nanosheets. Further, the Ti3C2Tx/NH2-RGO binary structure provides a conducting matrix to the metal selenides and prevents their agglomeration tendency. Superior electrocatalytic activity was obtained from Ti3C2Tx/NH2-RGO/MoSn2Se4 electrocatalyst with an onset potential of 1.3 V [vs. Reversible Hydrogen Electrode (RHE)], lower overpotential (η10) of 50 mV, large electrochemically active surface area, and smaller Tafel slope of 55.9 mV/dec with durable electrocatalytic performance. The assembled asymmetric supercapacitor device using our synthesized material as cathode showed excellent performance with high specific capacitance (120.2 F/g), large energy density (42.7 W/h/kg), and ultrastability with 97% capacitance retention after 10,000 charging–discharging cycles. The prepared ternary composite has been synthesized for the first time and has also performed better than the previous reports of its kind. This work provides an overall insight into designing an electrode material for both efficient oxygen evolution as well as high performance supercapacitor device.