Solventless Preparation of Thoria and Its Inclusion into SiO₂ and TiO₂: A Luminescence and Photocatalysis Study.

ABSTRACT: Thoria was prepared using a solid-state method from the macromolecular precursor Chitosan·Th(NO₃)₄ (chitosan) and PS-co-4-PVP·Th(NO₃)₄ (PVP). The morphology and the average size of ThO₂ depend of the chitosan and PS-co-4-PVP polymer forming the precursor. Their photoluminescent properties were investigated, finding a dependence of their intensity emission maxima, with the nature of the precursor polymer. The photocatalytic activity of ThO₂ toward the degradation of methylene blue was measured for the first time, finding a degradation of about 66% in 300 min. The inclusion of ThO₂ into SiO₂ and TiO₂ was achieved by the solid-state pyrolysis of the macromolecular composites Chitosan·Th(NO₃)₄//MO₂ and PS-co-4-PVP·Th(NO₃)₄//MO₂, MO₂ = SiO₂ or TiO₂. The ThO₂ exhibits a homogeneous dispersion inside the silica, showing sizes of about 40 and 50 nm for the chitosan and PVP polymer precursors, respectively. The luminescent properties of the ThO₂/SiO₂ and ThO₂/TiO₂ composites were also studied, finding a decrease in intensity when introducing the SiO₂ or TiO₂ matrices. The photocatalytic behavior to methylene blue degradation of ThO₂ and their composites ThO₂/SiO₂ and ThO₂/TiO₂ was investigated for the first time, with them in the following order: ThO₂ > ThO₂/TiO₂ > ThO₂/SiO₂.

SUBMITTER: Diaz C 

PROVIDER: S-EPMC8047679 | biostudies-literature | 2021 Apr

REPOSITORIES: biostudies-literature