A study on surface chemistry of dielectric confined CeO2 QDs via ligand (ACTP) to ligand charge transfer

Abstract

Here, we tried to ensure the accurate landscape of ceria QDs surface chemistry using soft X-ray absorption spectroscopy (SXAS) based on insight into the clear-cut electronic structure analyses. From the perspective of molecular orbital (MO) energy level diagram, final state electronic transition of Ce3+ in Oh field has been observed using X-ray absorption near edge region enclosing Ce, MIV-3d3/2 and MV-3d5/2 edges. Information about subtle surface distortion owing to the adsorption of ACTP anchoring group in facilitating efficient charge transfer on the ceria defect site has been qualitatively enlightened by invoking the concept of coordination chemistry. The proximity of the description was further implemented by qualitative analysis of O K-edge X-ray absorption near edge structure (XANES) spectra. Conversely, an increase in O 2p-to-Ce 5d-eg and 5d-t2g surface hybridization via essential oxygen-to-organic ligand interfacial charge transfer was found to be the reason for altered the coordination environment of Ce, provide a shred of direct evidence for the influence of ACTP on CeO2 QD surface. This perspective makes the sense of how recent SXAS technique helps to uncover the complex surface chemistry of ACTP capped CeO2 QDs and affords valuable insight into the specific coordination environment through ligand-to-ligand charge transfer.