Nuni Widiarti, Lisnawaty Simatupang, Kerista Tarigan, Dimas Gilang Ramadhani
Oxide–carbon heterointerfaces are promising catalytic platforms because interfacial coupling can tune structural stability, charge redistribution, adsorption behavior, kinetic accessibility, and dynamic robustness. Spin-polarized first-principles density functional theory was used to investigate six comparative models: S0 (rGO), S1 (NiO/rGO), S2 (ZnO/rGO), S3 (NiO–ZnO/rGO), C1 (NiO), and C2 (ZnO). The model hierarchy distinguishes the support effect, oxide-identity effect, and dual-oxide heterointerface effect within one consistent framework. Structural analysis shows that S3 forms the most stabilized heterointerface, with a binding energy of −30.13 eV, compact oxide–support distances of 2.15/2.28 Å, and a formation energy of −1.95 eV. Electronic analysis indicates that S3 produces the strongest charge redistribution, with ΔQ → rGO = −0.68 e and the lowest supported-model work function of 4.63 eV. Adsorption calculations identify the Ni–O–Zn bridge as the strongest adsorption motif, with adsorption energies of −2.11, −2.61, −1.52, and − 0.61 eV for OH*, O*, OOH*, and H*, respectively. OER free-energy analysis shows that S2 has the lowest calculated overpotential of 4.73 V, whereas S3 gives 4.96 V due to overbinding. CI-NEB and AIMD results indicate that S3 remains kinetically accessible and dynamically robust, highlighting the need for descriptor-specific catalyst design in mixed-oxide/rGO electrocatalysts. © 2026 The Authors.
Chemistry Education Study Program, Faculty of Mathematics and Natural Sciences, Universitas Negeri Semarang, Semarang, Indonesia; Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Negeri Medan, Medan, Indonesia; Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Sumatera Utara, Medan, Indonesia
