Three-Dimensional Reduced Graphene Hydrogels Using Various Carbohydrates for High Performance Supercapacitors.

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Graphene oxide (GO) is a precursor for advanced materials.
• Developing efficient methods for reduced graphene hydrogels (RGHs) is crucial for energy storage.
• Carbohydrates offer a sustainable and effective route for GO reduction.

Purpose of the Study:

• To synthesize three-dimensional (3D) reduced graphene hydrogels (RGHs) using common carbohydrates.
• To characterize the structural and morphological properties of the synthesized RGHs.
• To evaluate the electrochemical energy storage performance of RGHs.

Main Methods:

• Preparation of RGHs via a facile strategy using glucose, fructose, and sucrose as reducing agents in an aqueous GO solution with ammonia.
• Characterization using X-ray powder diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), and N2 sorption.
• Electrochemical performance evaluation including specific capacitance and cycling stability.

Main Results:

• Successful synthesis of 3D RGHs confirmed by multiple spectroscopic and microscopic techniques.
• RGHs exhibit abundant porous architectures suitable for ionic transport.
• High specific capacitance values achieved: up to 153.5 F g−1 (fructose), 145.0 F g−1 (glucose), and 150.3 F g−1 (sucrose) at 0.3 A g−1.
• Good capacitance retention (46.9–61.5%) at high current density (20 A g−1).
• Demonstrated good electrochemical stability and reversibility.

Conclusions:

• Carbohydrates are effective reducing agents for preparing 3D RGHs from GO.
• The porous structure of RGHs facilitates efficient electrochemical energy storage.
• The synthesized RGHs show potential as electrode materials for supercapacitors.