A facile synthesis of high quality nanostructured CeO2 and Gd2O3-doped CeO2 solid electrolytes for improved electrochemical performance

Abstract

This study describes the use of a composite nitrate salt solution as a precursor to synthesize CeO₂ and Gd₂O₃-doped CeO₂ (GDC) nanoparticles (NPs) using an atmospheric pressure plasma jet (APPJ). The microstructures of CeO₂ and GDC NPs were found to be cubical and spherical shaped nanocrystallites with average particle sizes of 10.5 and 6.7 nm, respectively. Reactive oxygen species, detected by optical emission spectroscopy (OES), are believed to be the major oxidative agents for the formation of oxide materials in the APPJ process. Based on the material characterization and OES observations, the study effectively demonstrated the feasibility of preparing well-crystallized GDC NPs by the APPJ system as well as the gas-to-particle mechanism. Notably, the Bader charge of CeO₂ and Ce_0.9Gd_0.1O₂ characterized by density function theory (DFT) simulation and AC impedance measurements shows that Gd helps in increasing the charge on Ce_0.9Gd_0.1O₂ NPs, thus improving their conductivity and making them candidate materials for electrolytes in solid oxide fuel cells.