Influence of the structural properties and W/Nb ratio upon the photocatalytic activity of tungsten-doped potassium sodium niobate-based perovskites

A key challenge in photocatalytic pollutant degradation lies in enhancing the efficiency of perovskite-based catalysts prepared under mild experimental conditions. The incorporation of tungsten (W) into nanostructured hollow particles of alkali niobates was studied as a strategy to improve photocata...

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Detalhes bibliográficos
Autores: Praxedes, Fabiano R. [UNESP], Nobre, Marcos A.L. [UNESP], Lanfredi, Silvania [UNESP], Poon, Po S., Matos, Juan
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2025
País:Brasil
Recursos:Universidade Estadual Paulista (UNESP)
Repositório:Repositório Institucional da UNESP
Idioma:inglês
OAI Identifier:oai:repositorio.unesp.br:11449/299327
Acesso em linha:http://dx.doi.org/10.1016/j.materresbull.2024.113256
https://hdl.handle.net/11449/299327
Access Level:Acceso aberto
Palavra-chave:Alkali niobate
Basic Blue 41 azo-dye
Perovskite
Photocatalysis
Tungsten
Descrição
Resumo:A key challenge in photocatalytic pollutant degradation lies in enhancing the efficiency of perovskite-based catalysts prepared under mild experimental conditions. The incorporation of tungsten (W) into nanostructured hollow particles of alkali niobates was studied as a strategy to improve photocatalytic activity. X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), N2 adsorption/desorption isotherms, Raman and UV–Vis spectroscopies confirmed the successful formation of W-doped K0.5Na0.5NbO3 hollow spherical particles with a monoclinic perovskite structure. Detailed analysis by Rietveld refinement revealed improved octahedral distortion induced by W doping. The photocatalytic activity was evaluated using the molecular density of adsorbed azo dye and the first-order apparent rate-constant, revealing that W-doped samples demonstrated significantly higher activity (3.31×10–2 molecules·nm–2·min–1) compared to the host structure (1.05×10–2 molecules·nm–2·min–1). Based on scavenger tests and mass spectroscopy analysis, a mechanism for the photocatalytic oxidation of the azo dye is proposed.