This study investigates the structural, electronic, and magnetic properties of pristine, hydrogenated, and oxygenated Cr 2 O 3 monolayer honeycomb-kagome (HK) surface using first-principles calculations based on density functional theory (DFT). Molecular dynamics and phonon dispersion calculations demonstrate the thermal and dynamic stability of these systems, implying their feasibility for ... [Show full abstract] laboratory synthesis. The results revealed that the adsorption of hydrogen and oxygen atoms on the Cr 2 O 3 monolayer surface exhibited negative adsorption energies, indicating that these structures are energetically favorable. Specifically, the adsorption of oxygen atoms transforms the initial half-metallic nature of the monolayer into semiconducting behavior. Moreover, the introduction of hydrogen and oxygen atoms considerably enhances the Curie temperature of the surface. These findings offer a practical approach for enhancing the electronic and magnetic properties of Cr 2 O 3 monolayer HK surface, thereby facilitating their prospective application in spintronics.