Unraveling the Origin of Photocatalytic Deactivation in CeO₂/Nb₂O₅ Heterostructure Systems during Methanol Oxidation: Insight into the Role of Cerium Species

The study provides deep insight into the origin of photocatalytic deactivation Nb2O5 after modification with ceria. Of particular interest was to fully understand role ceria species in diminishing performance CeO2/Nb2O5 heterostructures. For this purpose, loaded on niobia surfaces by wet impregnation. as-prepared materials were characterized powder X-ray diffraction, nitrogen physisorption, UV–visible spectroscopy, photoelectron high-resolution transmission electron microscopy, and photoluminescence measurements. Photocatalytic activity parent metal oxides (i.e., CeO2) heterostructures different loadings tested methanol photooxidation, a model gas-phase reaction. Deep process provided operando-IR techniques combined results studies revealed that resulted from increased recombination photo-excited electrons holes. main factor contributing more efficient charge carriers ultrafine size species. presence such highly dispersed surface strong interface between these two semiconductors, enabling transfer CeO2. However, supported exhibited high defect site concentration, which acted as active centers for photo-induced carriers.