Tuning the electronic properties of C30B15N15 fullerene via encapsulation of alkali and alkali earth metals

Encapsulation of several alkali and alkali earth metals inside a C30B15N15 nanocage was investigated by using density functional calculations at B3LYP and M06-2X levels of theory. It was found that the encapsulation processes are spontaneous at room temperature and 1 atm pressure. The encapsulation favorability increases in the series: K > Na > Ca > Li > Mg > Be. Alkali earth metals influence the electronic properties of cluster relatively more compared to alkali metals. A tunable HOMO–LUMO energy gap of up to ∼1.05 eV was predicted for C30B15N15 by the controlled encapsulation of different alkali and alkali earth metals at B3LYP/6-31G (d). Electron emission density from C30B15N15 surface will be significantly increased upon the Ca encapsulation, while in the case of Li capsulation it will be decreased based on work function calculations in our work. The thermodynamic results of B3LYP and M06-2X functionals are somewhat similar, while those of electronic properties are significantly different.