FCT: DCM - Capítulos de livros
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- A mina de estanho antiga de Vale do Mouro (Coriscada, Mêda, Guarda)Publication . Meunier, Emmanuelle; Dias, Filipa; Lima, Alexandre; Jorge Cordeiro Silva, Rui; Mirão, José; Figueiredo, Elin; DCM - Departamento de Ciência dos Materiais; CENIMAT-i3N - Centro de Investigação de Materiais (Lab. Associado I3N)Resumo: Apresentamos os dados procedentes do estudo da mina de Vale do Mouro (Coriscada, Mêda, Guarda), situada no granito sin-tectónico de Mêda. Os vestígios de mineração são numerosos neste local, alguns deles relacionados com a exploração moderna de volfrâmio. A presença de cassiterite fica contudo confirmada por análise de minério procedente de antigas escombreiras. A vala mineira estudada tem características técnicas coerentes com uma exploração antiga. Discute-se a importância que esta atividade pôde ter no período romano, tendo em conta os dados disponíveis sobre a exploração mineira antiga da zona. Abstract: This paper presents the data obtained during the study of the mine of Vale do Mouro (Coriscada, Mêda, Guarda), located in the syn-tectonic granite of Mêda. There are many mining vestiges in this place, some of them related with the modern exploitation of tungsten. The presence of cassiterite is nevertheless confirmed by the analysis of ore from ancient waste heaps. The technical characteristics of the studied mining trench are consistent with an ancient activity. A discussion of the importance that mining could have had during the Roman period is made, combining the available information about ancient mining in this area.
- Porous ZnO Nanostructures Synthesized by Microwave Hydrothermal Method for Energy Harvesting ApplicationsPublication . Ferreira, Sofia Henriques; Rovisco, Ana; Santos, Andreia dos; Aguas, Hugo; Igreja, Rui; Barquinha, Pedro Miguel Cândido; Fortunato, Elvira; Martins, Rodrigo; DCM - Departamento de Ciência dos Materiais; CENIMAT-i3N - Centro de Investigação de Materiais (Lab. Associado I3N); UNINOVA-Instituto de Desenvolvimento de Novas TecnologiasThe ever-growing global market for smart wearable technologies and Internet of Things (IoT) has increased the demand for sustainable and multifunctional nanomaterials synthesized by low-cost and energy-efficient processing technologies. Zinc oxide (ZnO) is a key material for this purpose due to the variety of facile methods that exist to produced ZnO nanostructures with tailored sizes, morphologies, and optical and electrical properties. In particular, ZnO nanostructures with a porous structure are advantageous over other morphologies for many applications because of their high specific surface area. In this chapter, a literature review on the latest progress regarding the synthesis and applications of ZnO with a porous morphology will be provided, with special focus on the synthesis by microwave hydrothermal method of these nanomaterials and their potential for application in energy harvesting devices. Nanogenerators of a composite made by polydimethylsiloxane (PDMS) and porous ZnO nanostructures were explored and optimized, with an output voltage of (4.5 ± 0.3) V being achieved for the best conditions. The daily life applicability of these devices was demonstrated by lighting up a commercial LED, by manually stimulating the nanogenerator directly connected to the LED.
- Hydrothermal Synthesis of Zinc Tin Oxide Nanostructures for Photocatalysis, Energy Harvesting and ElectronicsPublication . Rovisco, Ana; Branquinho, Rita; Sarmento, Joana Maria Doria Vaz Pinto Morais; Martins, Rodrigo Ferrão de Paiva; Fortunato, Elvira; Barquinha, Pedro Miguel Cândido; UNINOVA-Instituto de Desenvolvimento de Novas Tecnologias; DCM - Departamento de Ciência dos Materiais; CENIMAT-i3N - Centro de Investigação de Materiais (Lab. Associado I3N)The massification of Internet of Things (IoT) and Smart Surfaces has increased the demand for nanomaterials excelling at specific properties required for their target application, but also offering multifunctionality, conformal integration in multiple surfaces and sustainability, in line with the European Green Deal goals. Metal oxides have been key materials for this end, finding applications from flexible electronics to photocatalysis and energy harvesting, with multicomponent materials as zinc tin oxide (ZTO) emerging as some of the most promising possibilities. This chapter is dedicated to the hydrothermal synthesis of ZTO nanostructures, expanding the already wide potential of ZnO. A literature review on the latest progress on the synthesis of a multitude of ZTO nanostructures is provided (e.g., nanowires, nanoparticles, nanosheets), emphasizing the relevance of advanced nanoscale techniques for proper characterization of such materials. The multifunctionality of ZTO will also be covered, with special attention being given to their potential for photocatalysis, electronic devices and energy harvesters.
- Cellulose-Based Bioelectronic DevicesPublication . Baptista, Ana Catarina; Ferreira, Isabel Maria Mercês; Borges, João Paulo Miranda Ribeiro; DCM - Departamento de Ciência dos Materiais; CENIMAT-i3N - Centro de Investigação de Materiais (Lab. Associado I3N)
- Electrodeposition of WO3 Nanoparticles for Sensing ApplicationsPublication . Santos, Lídia Sofia Leitão; Neto, J.; Crespo, Ana; Baião, Pedro; Barquinha, Pedro Miguel Cândido; Pereira, Luis Miguel Nunes; Martins, Rodrigo Ferrão de Paiva; Fortunato, Elvira Maria Correia; CENIMAT-i3N - Centro de Investigação de Materiais (Lab. Associado I3N); DCM - Departamento de Ciência dos Materiais; UNINOVA-Instituto de Desenvolvimento de Novas TecnologiasThe motivation of using metal oxides is mainly due to its charge storage capabilities, and electrocatalytic, electrochromic and photoelectrochemical properties. But comparing with bulk, nanostructured materials present several advantages related with the spatial confinement, large fraction of surface atoms, high surface energy, strong surface adsorption and increased surface to volume ratio, which greatly improves the performances of these materials. The deposition of this materials can be accomplished by a variety of physical and chemical techniques but nowadays, electrodeposited metal oxides are generally used in both laboratories and industries due to the flexibility to control structure and morphology of the oxide electrodes combined with a reduced cost. Tungsten oxide (WO3) is a well-studied semiconductor and is used for several applications as chromogenic material, sensor and catalyst. The major important features is its low cost and availability, improved stability, easy morphologic and structural control of the nanostructures, reversible change of conductivity, high sensitivity, selectivity and biocompatibility. For the electrodeposition of WO3, more than one method can be adopted: electrodeposition from a precursor solution, anodic oxidation, and electrodeposition of already produced nanoparticles; however, in this case the mechanism of the electrodeposition is not fully understood. In this chapter, a review of the latest published work of electrodeposited nanostructured metal oxides is provided to the reader, with a more detailed explanation of WO3 material applied in sensing devices.