High-performance CeO₂/rGO hybrid nanostructures as bifunctional electrocatalysts for water-splitting

Area of Science:

• Materials Science
• Nanotechnology
• Electrochemistry

Background:

• Two-dimensional reduced graphene oxide (rGO) combined with rare-earth metal oxides like ceria (CeO2) offers enhanced electrocatalytic activity for water-splitting.
• Developing efficient hydrogen-evolving materials is crucial for sustainable energy technologies.

Purpose of the Study:

• To synthesize and characterize a novel ceria/reduced graphene oxide (CeO2/rGO) nanostructure.
• To evaluate the electrocatalytic performance of the CeO2/rGO nanostructure for water-splitting applications.

Main Methods:

• One-pot hydrothermal synthesis was employed to create the CeO2/rGO nanostructure.
• Characterization techniques included X-ray Diffraction (XRD), Photoluminescence (PL) spectroscopy, UV-visible spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), and High-Resolution Transmission Electron Microscopy (HR-TEM).
• Electrocatalytic activity was assessed using Tafel slope and overpotential measurements.

Main Results:

• XRD confirmed the formation of CeO2 within the rGO layers.
• PL spectra indicated strong interfacial interactions between CeO2 nanoparticles and rGO.
• FESEM and HR-TEM revealed evenly distributed CeO2 nanoparticles (20-30 nm) on rGO sheets.
• The CeO2/rGO nanostructure exhibited a smaller Tafel slope (~168 mV dec⁻¹) compared to individual components and bare electrodes.
• An overpotential of 260 mV was required to achieve a current density of -50 mA cm⁻², signifying superior catalytic activity.

Conclusions:

• The CeO2/rGO nanostructure demonstrates excellent electrocatalytic activity for water-splitting.
• The synergistic effect between CeO2 and rGO enhances the material's performance.
• This nanostructure presents a promising candidate for efficient hydrogen evolution in water-splitting devices.