Table 4.

Calculated atomic, molecular adsorption energies, co-adsorption energies (${\mathrm{\Delta }E}_{\mathit{ads}}^H$,${\mathrm{\Delta }E}_{\mathit{ads}}^{H2}$ (eV)$,{\mathrm{\Delta }E}_{co-ads}^{H-H}$), free adsorption energies, and Energy barrier for the formation of H₂ by photocatalytic reaction mechanism on the different studied surfaces.

Models/surfaces	${\mathrm{\Delta }E}_{\mathit{ads}}^H$ (eV)	${\mathrm{\Delta }E}_{co-ads}^{H-H}$ (eV)	${\mathrm{\Delta }E}_{\mathit{ads}}^{H2}$ (eV)	${\mathrm{\Delta }G}_H^{\ast }$ (eV)	Energy barrier (eV)
H2@C24 (Ha)	− 1.809	15.00	− 16.314	− 1.069	4.57
H2@Nidop*Caenc.C24 (Hb)	− 0.137	− 14.18	− 16.587	− 0.103	1.93
H2@Caenc.C24 (Hc)	− 1.463	14.55	− 28.255	− 1.223	2.42
H2@Agdec*Nidop.Caenc.C24(Hd)	− 1.965	− 15.33	− 16.470	− 1.575	0.82

Unit of conversion (1 Hartree = 27.211 eV); dop = doped, enc. = encapsulated, dec. = decorated.