Highly Active 2D Layered MoS ₂ -rGO Hybrids for Energy Conversion and Storage Applications

Area of Science:

• Materials Science
• Electrochemistry
• Renewable Energy

Background:

• Efficient materials for renewable energy generation and storage are crucial for future energy demands.
• Molybdenum disulphide (MoS2) and graphene-based materials are promising candidates for energy applications.

Purpose of the Study:

• To synthesize and explore molybdenum disulphide hollow spheres (MoS2-HS) and their hybrid with reduced graphene oxide (rGO/MoS2-S) for energy generation and storage.
• To investigate the electrochemical performance of these materials for hydrogen evolution reaction (HER) and supercapacitor applications.

Main Methods:

• Synthesis of MoS2 hollow spheres and rGO/MoS2-S hybrid materials.
• Characterization of material morphology, crystallinity, and elemental composition.
• Electrochemical testing for hydrogen evolution and supercapacitor performance, including cyclic stability and prototype fabrication.

Main Results:

• The rGO/MoS2-S hybrid exhibited enhanced gravimetric capacitance (318 ± 14 Fg-1) and superior specific energy/power outputs (44.1 ± 2.1 Whkg-1 and 159.16 ± 7.0 Wkg-1).
• The material demonstrated excellent cyclic performance, retaining 82 ± 0.95% after 5000 cycles.
• Remarkably superior HER performances were observed with a lower onset overpotential (0.16 ± 0.05 V) and Tafel slope (75 ± 4 mVdec-1).

Conclusions:

• The rGO/MoS2-S hybrid material offers a unique balance of exposed edge sites and electrical conductivity, leading to superior electrochemical performance.
• The dual functionality of rGO/MoS2-S substantiates its promising application for both hydrogen generation and supercapacitor energy storage.
• A functional supercapacitor prototype was successfully fabricated and demonstrated, highlighting the practical potential of the developed material.