Graphene/nickel nanoparticles composites from graphenide solutions.

Area of Science:

• Materials Science
• Nanotechnology
• Electrochemistry

Background:

• Graphene and nickel nanoparticles are promising materials for electrochemical applications.
• Developing efficient synthesis methods for nickel-graphene nanocomposites is crucial for enhancing their performance.
• Understanding the influence of synthesis conditions on material properties is key to optimizing nanocomposite behavior.

Purpose of the Study:

• To synthesize nickel-graphene nanocomposites using a novel method involving nickel cations and graphenide solutions.
• To investigate the effect of different solvents (NMP and THF) and nickel/graphene ratios on the resulting nanomaterials.
• To characterize the synthesized nanocomposites and evaluate their electrochemical performance.

Main Methods:

• Synthesis of nickel-graphene nanocomposites via reduction of nickel cations by graphenide in NMP and THF.
• Characterization using UV-Vis spectroscopy, TEM, SEM, TGA, AFM, XPS, and EDS.
• Electrochemical evaluation of thin films on ITO substrates in alkaline medium using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS).

Main Results:

• Successfully synthesized nickel-graphene nanocomposites with graphene layers decorated by 2-10 nm crystalline nickel nanoparticles.
• Electrochemical characterization revealed a Ni(OH)2/NiOOH redox pair, with higher nickel content leading to increased peak currents.
• Nanocomposites prepared in NMP demonstrated a fivefold increase in peak currents and lower charge transfer resistance compared to those from THF.

Conclusions:

• The synthesis method effectively produces well-decorated nickel-graphene nanocomposites.
• Solvent choice significantly impacts the electrochemical performance of the nickel-graphene nanocomposites, with NMP yielding superior results.
• These NMP-derived nanocomposites show great potential for electrochemical applications due to their enhanced activity and conductivity.