Paper-based nanoplatforms for multifunctional applications

• Autor(a) principal: Matias, Maria Leonor Joaquim do Nascimento
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/58117
• topic: cellulose paper; TiO2; ZnO; UV sensors; photocatalysis; antibacterial activity; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia dos Materiais

In this work, zinc oxide (ZnO) and titanium dioxide (TiO2) nanostructures were grown on different cellulose paper substrates, namely Whatman, office, and commercial hospital papers, using a hydrothermal method assisted by microwave irradiation. Pure ZnO and TiO2 nanostructures were synthesized, however the growth of TiO2 above the ZnO was also investigated to produce a uniform heterostructure. Continuous ZnO nanorod arrays were grown on Whatman and hospital papers, however on office paper, it could be observed the formation of nanoplates originating nanoflower structures. TiO2 nanoparticles homogeneously covered all the substrates and, in some conditions, forming uniform TiO2 films. The structural characterization was carried out by SEM coupled with EDS, XRD and Raman spectroscopy. The optical characterization of all the materials was carried out. The produced materials were investigated for multifunctional applications, like photocatalyst agents, bacterial inactivators and ultraviolet (UV) sensors. To evaluate the photocatalytic activity under UV and solar radiations, rhodamine B was the model-test contaminant indicator and the best photocatalytic activity was achieved with Whatman paper. Hospital paper with TiO2 nanoparticles showed significant antibacterial properties against Staphylococcus aureus. ZnO-based UV sensors on Whatman demonstrated a responsivity of 0.61 μA W-1.