Direct acidic graphene oxide enabled fabrication of three-dimensional molybdenum trisulfide and reduced graphene oxide nanohybrid aerogels with simultaneous energy storage and electrocatalytic capability

Abstract

To confront the ever-growing energy and environmental concerns, the rational design and development of newer yet high-performance energy storage and conversion materials are highly desirable. Herein, we proposed a scalable and simplistic approach to prepare a three-dimensional (3D) MoS3/reduced graphene oxide (RGO) aerogel as an efficient electroactive material. Under a benign in-situ hydrothermal method, an acidic graphene oxide was directly used as support and catalyst to form uniformly dispersed MoS3 nanoparticles within porous 3D RGO architecture. Owing to its unique synergy of plentiful exposed active sites and highly porous conductive network, the resulting nanohybrid was successfully used as a supercapacitor electrode and electrocatalyst for hydrogen evolution reaction (HER). The as-obtained 3D MoS3/RGO nanohybrid-based electrode provides a higher specific capacitance of 576.5 F·g−1, more significant than the pristine MoS3 electrode (206.4 F g−1). Likewise, an asymmetric supercapacitor (ASC) device assembled using the MoS3/RGO and activated carbon (AC) delivers a maximum energy density of 35.2 Wh kg−1 at a power density of 528 W kg−1, over a voltage window of 1.5 V. Moreover, remarkable cycling stability accompanied by 92% capacitance retention was also observed. Similarly, the resulting 3D MoS3/RGO nanohybrids display significant HER activity, requiring a smaller overpotential of only 0.121 V to accomplish a current density of 10 mA·g−1 in conjunction with a smaller Tafel slope value of 60 mV dec−1 in 0.5 M H2SO4. Such remarkable electrocatalytic activity is accredited to its unique porous nanoarchitecture, sulfur-rich active centers, and improved conductivity. Overall, the implemented optimal methodology offers technological scalability in the fabrication of low-cost 3D nanohybrids electrodes composed of graphene and TMDs for various energy-related applications.