Browsing by Subject "nanomaterials"
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(2021)Plasmonic catalysis utilises light energy to drive chemical reactions. Compared to conventional catalytic processes, which are run by high temperatures and pressures, light-driven processes can lower energy consumption and increase selectivity. Conventional plasmonic nanoparticles (Ag, Au) are relatively scarce and expensive, and therefore the use of materials with earth-abundant elements in plasmonic catalysis is widely pursued. Despite their good optical properties, plasmonic nanoparticles are often unsuitable catalysts. Hybrid catalysts, structures consisting of a light-harvesting plasmonic part and a catalytical centre of different material, have emerged as an opportunity to address these challenges and obtain desired properties. This thesis consists of two parts: In the first part, properties of plasmonic materials are described, and previous studies of hybrid catalysts with earth-abundant plasmonic materials are reviewed. Experimental work on plasmonic-catalytic nanohybrids, with TiN as the plasmonic part and Pd as the catalytic entity, is described in the second part. In this context, a Pd/TiN (Pd nanoparticles supported into TiN) catalyst was synthesised, characterised and applied to test catalytical reactions. Contrary to the hypothesis, light-induced rate enhancement was not observed in our current catalytical studies. These results call for further optimisation of synthesis and reaction conditions to prepare an earth-abundant, light-active catalyst.
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(2014)This study explores the research, characteristics, manufacturing processes, safety and applications of graphene from the perspective of pharmacy and medicine. The study also examines how graphene research and commercialization has developed in the last ten years (2004-2013), with an emphasis on biomedical research globally and separately in Finland. The methods employed are an extensive literature review of scientific publications, and a survey of the biomedical research emphases, geographical distribution, and funding of graphene research based on article and patent databases. Graphene holds considerable potential in pharmaceutical use. Clinical trials can commence as soon as the manufacturing processes develop to produce graphene of sufficient quality. The variety of biomedical uses of graphene is vast: antibacterial products and coatings, gene therapy, tissue technology, sensor and imaging technology, as well as utilization in drug delivery. Graphene can be used to enhance therapeutic effectiveness by creating instruments for targeted and controlled drug delivery. In addition to uses in therapeutics, graphene offers possibilities for diagnostics. The biomedical research and commercialization of graphene have accelerated in the recent years, but research and patenting activity has concentrated in Asia, and especially in China. The research has been university driven and primarily publicly funded. In Finland, graphene research has focused on electrical applications, whereas research in the fields of pharmacy and medicine has been limited. As a so-called high-tech country, Finland could increase research into graphene as an innovative pharmaceutical instrument.
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(2022)Molecular hydrogen is considered as the primary alternative to replace fossil fuels for future energy supply. Hydrogen can be produced sustainably through electrocatalytic hydrogen evolution reaction which is a vital step in water electrolysis. So far, the efficiencies of electrochemical and photoelectrochemical water electrolysis systems are too low to satisfy the demands for hydrogen on a commercial scale. Plasmonic nanostructures containing a plasmonic and a catalytic component hold great promise for enhancing the performance of typical water electrolysis systems through plasmonic photocatalysis utilizing localized surface plasmon resonance excitation. Here, a novel plasmonic-catalytic u@AgPd nanorattle is synthesized, characterized, and investigated for plasmon-enhanced hydrogen evolution reaction to provide new insights into the design of light-assisted water electrolysis systems. The nanorattle exhibited significant improvements of performance towards hydrogen evolution reaction under 427 nm illumination, displaying a near 2-fold current increase and a decreased overpotential of 58 mV at a current density of 10 mAcm-2. The material is evidenced to plasmon-enhance the electrocatalytic performance through a combination of charge transfer and local heating mechanisms.
Now showing items 1-3 of 3