▎ 摘　　要

This work demonstrates a novel approach to application of in situ Raman spectroscopy to study laser-induced stabilization of reduced nanoceria (CeO2-x) supported on graphene-a promising nanocomposite for future development of nanomaterial-enabled gas sensors or vital catalysts for hydrogenation of alcohols under anaerobic conditions. Structural stabilization of CeO2-x nanoparticles (NPs) on a graphene surface is evidenced by significant modification of Raman spectra-the appearance, increase in relative intensity, and low-wavenumber shift of CeO2 F-2g band at excitation laser powers higher than similar to 5 mW. The effect is related to the reduction in a number of oxygen vacancies in CeO2-x NPs. Analysis of the graphene 2D and G band wavenumbers through omega(2D)(omega(G)) correlation indicated a decrease in p-type graphene doping attributed to the charge transfer between the stabilizing CeO2-x NPs and the graphene that occurs due to trapping of graphene mobile holes by oxygen vacancies in CeO2-x. High-resolution transmission electron microscopy analysis supported this idea by showing the increased lattice constant of fluorite-type hexagonal-shaped CeO2-x NPs as compared with bulk CeO2 and which could be related to partial reduction of CeO2-x NPs as a result of the Ce4+ transformation to Ce3+ with formation of corresponding oxygen vacancies. X-ray photoelectron spectroscopy data confirmed the mixed Ce4+/Ce3+ valence state of the CeO2-x NPs. Thus, by combining the structure conversion of nanoceria induced by electromagnetic radiation and its stabilization by the graphene support, this work provides a foundation for advanced concepts in the development of the next-generation catalysts and sensors.