RT journal article
T1 Rapid microwave hydrothermal synthesis of rare Earth-modified ZnO photocatalysts: Enhanced activity and comprehensive structural analysis
A1 Bazta, Otman
A1 Ramos Justicia, Juan Francisco
A1 Urbieta, Ana
A1 Trasobares Llorente, Susana
A1 Fernández, Paloma
A1 Calvino Gámez, José Juan
A1 Hungría Hernández, Ana Belén
A2 Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica
K1 ZnO nanosheets
K1 Surface decoration
K1 Microwave-assisted hydrothermal synthesis
K1 Charge separation efficiency
K1 Nanostructured photocatalysts
K1 Rare earth modification
AB This study demonstrates that, under the specific synthesis conditions applied, the addition of rare earth ions(Ce³⁺, Y³⁺, Eu³⁺) to ZnO does not lead to their incorporation into the lattice as dopants but instead results in theirsurface decoration, as revealed by advanced nanoscale characterization.ZnO and rare earth-modified ZnO photocatalysts (ZnO:RE = ZnO:Eu, ZnO:Y, ZnO:Ce) with a rare earth (RE)concentration of 2 at.% were synthesized via a rapid and environmentally friendly microwave-assisted hydrothermal method. The effect of adding different RE elements on the structural, morphological, and photocatalyticproperties of the samples was systematically investigated. A thorough characterization was conducted using Xray diffraction (XRD), field emission scanning electron microscopy (FESEM), high-angle annular dark field(HAADF)-scanning transmission electron microscopy (STEM), energy-dispersive X-ray spectroscopy (EDX), andphotoluminescence spectroscopy (PL) at various excitation wavelengths and temperatures.XRD analysis confirmed that all ZnO:RE samples retained the hexagonal wurtzite crystal structure of ZnO.FESEM images revealed that pure ZnO consisted of randomly distributed smooth nanosheets, while the additionof RE elements led to the formation of small particles dispersed over the nanosheet surfaces. A detailed structuralanalysis using STEM revealed that the rare earth elements formed structures decorating the surface of ZnOnanosheets rather than being fully incorporated into the ZnO lattice, indicating a dispersion of RE species overthe ZnO matrix. This unique distribution significantly influenced the material’s properties.The photocatalytic performance of the ZnO:RE samples was evaluated through the degradation of methyleneblue (MB), demonstrating superior activity compared to pure ZnO and TiO2-P25. Among the modified samples,the cerium-modified ZnO (ZnO:Ce) exhibited the highest MB degradation efficiency. Furthermore, PL spectroscopy combined with TEM analysis provided critical insights into the relationship between defect characteristicsand photocatalytic activity, offering a deeper understanding of the mechanisms driving performance enhancement. These findings highlight the potential of rare earth surface structures-ZnO nanosheets heterojunctions as astrategy for optimizing the photocatalytic properties of ZnO-based materials.
PB Elsevier
SN 2468-0230
YR 2025
FD 2025-09-11
LK http://hdl.handle.net/10498/38995
UL http://hdl.handle.net/10498/38995
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 21-sep-2026