Multi-Morphology CeO₂ Synthesis via Synergistic Induction by Solvent and Ammonium Bicarbonate

Area of Science:

• Materials Science
• Nanotechnology
• Green Chemistry

Background:

• Cerium dioxide (CeO2) is vital for catalysis and energy applications.
• Material performance heavily relies on its morphology.
• Conventional synthesis methods use environmentally concerning organic templates or surfactants.

Purpose of the Study:

• To develop an eco-friendly, surfactant-free synthesis for multi-morphology CeO2.
• To investigate the role of solvent systems and NH4HCO3 in CeO2 synthesis.
• To elucidate the synergistic effects on CeO2 nucleation and growth.

Main Methods:

• Utilized a methanol-water (MeOH-H2O) mixed solvent system.
• Employed NH4HCO3 as an inexpensive structure-directing agent.
• Systematically varied Ce:N molar ratios and reaction times.

Main Results:

• Achieved controllable synthesis of diverse CeO2 morphologies (plates, dendrites, octahedra, hollow structures).
• Water addition in MeOH-H2O enhanced precursor crystallinity (61.4%) and promoted octahedra formation.
• NH4HCO3 controlled CeO2 size (~240-375 nm) and improved crystallinity, partially replacing high-temperature calcination.

Conclusions:

• Demonstrated a synergistic mechanism between solvents and NH4HCO3 for CeO2 synthesis.
• Established an environmentally friendly route for producing tailored CeO2 nanostructures.
• Highlighted the potential of this method for catalysis and energy storage applications.