Influence of Ag size and shape in dye photodegradation using silver nanoparticle/ZnO nanohybrids and polychromatic light

Autor(es)

Mota, Danielle Ramos ; Martini, William da Silva ; Pellosi, Diogo Silva

• Tipo de documento: Artigo Científico
• Fonte: Environmental Science and Pollution Research; v. 30, n. 20, p. 16-pg., 2023-03-27.

Resumo

In this work, we propose zinc oxide (ZnO) surface functionalization with plasmonic silver nanoparticles (AgNP) of different sizes and shapes (spheres, prisms, and rods) creating ZnO/AgNP nanohybrids. These were characterized by UV-Vis spectroscopy, X-ray diffraction, transmission electron microscopy, Fourier-transform infrared spectroscopy, diffuse reflectance spectroscopy, and photoluminescence spectroscopy. Surface functionalization with AgNP improved photocatalyst electronic properties, its visible light absorption, and slow electron/hole recombination on the ZnO surface. Photocatalysis assays performed with a polychromatic Hg lamp degraded methyl orange, a model of persistent organic pollutant in water. A systematic study showed that the photodegradation kinetics of the nanohybrids are significantly more efficient than pure ZnO (up to 18 times) and that AgNP size and especially its shape are important in dye degradation. Mechanistic studies revealed that degradation occurred by direct dye reduction on the ZnO surface holes, ZnO electron transfer to Ag followed by center dot O-2(-) formation, and direct injection of AgNP hot electrons in the ZnO conduction band. The last effect was stronger for anisotropic AgNP, which explains their high kinetic degradation rates. Therefore, the rational design in ZnO/AgNP nanohybrid engineering and a systematic approach used in this manuscript allowed a detailed description of photodegradation process that occur at ZnO/AgNP interface. Our results are not conclusive about AgNP size; on the other hand, it clearly demonstrates that anisotropic nanoparticles (as Ag rods and prims) present superior photodegradation efficiency and are promising particles for further large-scale use of solar-irradiated nanohybrids. (AU)

• Processo FAPESP: 20/03388-3 - Fotocatálise plasmônica: desenvolvimento de nanohíbridos de nanopartículas de prata/TiO2 visando a fotodegradação de resíduos industriais
• Beneficiário: Pedro de Souza Ono
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 19/01604-3 - Síntese assistida por luz visível de nanohíbridos de nanopartícula de prata/fotossensibilizadores em matriz polimérica e sua aplicação sinérgica em fototerapia
• Beneficiário: Diogo Silva Pellosi
• Modalidade de apoio: Auxílio à Pesquisa - Regular