Abstract
Metal oxides (XO₂) have been extensively studied experimentally and theoretically. However, atomistic insights into systems like ZrO₂ and CeO₂, critical in nanocatalysis, remain incomplete. Using ab initio density functional theory (DFT) with the FP-LAPW method in the Wien2k framework and the PBE exchange-correlation functional, we examined the physical and chemical properties of cubic Fm-3m oxides (XO₂, X = Ti, Zr, Hf, Ce). Lattice parameters increase with atomic mass except for HfO₂, which deviates due to stronger ionic bonding. ZrO₂ is the stiffest, followed by HfO₂, TiO₂, and CeO₂. Electronic analysis shows TiO₂′s narrow band gap (1.15 eV), ZrO₂′s and HfO₂′s wide gaps (3.16 and 3.77 eV), and CeO₂′s moderate gap (2.17 eV) with redox activity. PDOS analysis highlights O 2p and metal d-/f-orbital interactions. These results emphasize distinct properties influencing their applications in photocatalysis, dielectrics, and catalysis, warranting further exploration.

Key words
Ab initio, oxides, stiff, band gap, orbitals

Full text (789 KB)