Extensive first-principles molecular dynamics study on Li encapsulation into C₆₀ and its experimental confirmation.

Area of Science:

• Materials Science
• Computational Chemistry
• Nanotechnology

Background:

• Endohedral fullerenes, specifically Li+@C60, have potential applications in medicine and photovoltaics.
• Current production methods yield only ~1% Li+@C60 using plasma shower with 30 eV Li+ ions.
• Industrialization of endohedral fullerenes requires increased production ratios.

Purpose of the Study:

• To investigate methods for increasing the production ratio of Li+@C60.
• To explore the effect of ion impact parameters on Li+@C60 synthesis.
• To validate simulation findings with experimental results.

Main Methods:

• First-principles molecular dynamics simulations to model Li+ ion collisions with C60.
• Analysis of production ratios at varying kinetic energies (10-40 eV) and impact angles.
• Experimental validation using plasma shower, 7Li solid NMR, and ICP-AES.

Main Results:

• Maximum Li+@C60 production ratio increased to 5.1% (5.3%) with vertical 30 eV (40 eV) Li+ ion impact on a six-membered ring.
• Lower 10 eV impact energy yielded 1.3% production without C60 damage.
• Randomly oriented C60 resulted in lower production ratios (0.2-3.7%).
• Experimental yield of 4% at 30 eV confirmed simulation accuracy.

Conclusions:

• Vertical impact on six-membered rings significantly enhances Li+@C60 production.
• Controlling impact energy and orientation is key to optimizing synthesis.
• Cu(111) substrate or UV irradiation can further improve production ratios.
• Simulations accurately predict experimental outcomes, supporting their reliability.