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Nanostructured layers of semiconducting metal oxides in gas sensors
Bartoš, Dušan ; Pytlíček, Zdeněk (oponent) ; Bendová, Mária (vedoucí práce)
This diploma thesis discusses the gas sensor preparation via anodic oxidation. It names sensor types, deals with the sensing principle of electrochemical sensors in detail and submits sensor parameters. It describes preparation technology and characterization technology methods. In the experimental part, it focuses on both the measurement methodology and the electrochemical oxygen sensor covered with titanium dioxide nanocolumns fabrication. Not the least it discusses acquired research results.
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Utilization of porous anodic alumina for fabrication of nanostructured layers and their photoelectrochemical and optical applications
Lednický, Tomáš ; Vanýsek, Petr (oponent) ; Sulka, Grzegorz (oponent) ; Bendová, Mária (vedoucí práce)
Porous anodic alumina (PAA) is an oxide layer formed by anodic oxidation of aluminium. In addition to its vast industrial use, its popularity has exponentially expanded into the field of nanotechnology due to the discovery of the self-ordering growth of PAA, leading to a honeycomb-like nanostructure. Together with a simple fabrication and tuneable properties, PAA represents an inexpensive alternative to the nanoscale world. In the same spirit, this PhD thesis deals with methods utilizing the PAA to fabricate functional nanostructures. The first part of the thesis is focused on the PAA-assisted formation of titanium dioxide (TiO2) nanocolumn arrays and their possible application as photoanodes for the water-splitting reaction. TiO2 nanocolumns are formed by anodisation of superimposed Al layer over titanium substrate being so-called ‘PAA-assisted anodisation’. The present study demonstrates the electrochemical properties and photoelectrochemical performance of nanocolumns formed from nitrogen-enriched substrates modified by various thermal treatments. The major finding was that their hollow morphology causes their poor performance. This issue was addressed by developing a novel anodising strategy that originates from the extensive study of anodising parameters and their effect on the morphology and stability of nanocolumns. The second part demonstrates the fabrication of well-ordered gold nanoparticles (AuNPs) on a transparent substrate as a localized surface plasmon resonance (LSPR) sensor element. A key-stone of this multidisciplinary method is a combination of a self-ordering behaviour of PAA that produces the template for controlled solid-state dewetting (SSD) of a subsequently deposited thin film of gold. This work includes the detailed technical aspects of complete fabrication, starting with the template production from an aluminium sheet to forming AuNPs and their transfer to a transparent substrate. This part is concluded with the characterization of fabricated AuNP nanocomposites with a practical comparison of their bulk refractive index sensitivity and stability in time. Results show this large-scale and inexpensive technique can easily compete with other, more demanding, AuNP fabrication technologies.
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Utilization of porous anodic alumina for fabrication of nanostructured layers and their photoelectrochemical and optical applications
Lednický, Tomáš ; Vanýsek, Petr (oponent) ; Sulka, Grzegorz (oponent) ; Bendová, Mária (vedoucí práce)
Porous anodic alumina (PAA) is an oxide layer formed by anodic oxidation of aluminium. In addition to its vast industrial use, its popularity has exponentially expanded into the field of nanotechnology due to the discovery of the self-ordering growth of PAA, leading to a honeycomb-like nanostructure. Together with a simple fabrication and tuneable properties, PAA represents an inexpensive alternative to the nanoscale world. In the same spirit, this PhD thesis deals with methods utilizing the PAA to fabricate functional nanostructures. The first part of the thesis is focused on the PAA-assisted formation of titanium dioxide (TiO2) nanocolumn arrays and their possible application as photoanodes for the water-splitting reaction. TiO2 nanocolumns are formed by anodisation of superimposed Al layer over titanium substrate being so-called ‘PAA-assisted anodisation’. The present study demonstrates the electrochemical properties and photoelectrochemical performance of nanocolumns formed from nitrogen-enriched substrates modified by various thermal treatments. The major finding was that their hollow morphology causes their poor performance. This issue was addressed by developing a novel anodising strategy that originates from the extensive study of anodising parameters and their effect on the morphology and stability of nanocolumns. The second part demonstrates the fabrication of well-ordered gold nanoparticles (AuNPs) on a transparent substrate as a localized surface plasmon resonance (LSPR) sensor element. A key-stone of this multidisciplinary method is a combination of a self-ordering behaviour of PAA that produces the template for controlled solid-state dewetting (SSD) of a subsequently deposited thin film of gold. This work includes the detailed technical aspects of complete fabrication, starting with the template production from an aluminium sheet to forming AuNPs and their transfer to a transparent substrate. This part is concluded with the characterization of fabricated AuNP nanocomposites with a practical comparison of their bulk refractive index sensitivity and stability in time. Results show this large-scale and inexpensive technique can easily compete with other, more demanding, AuNP fabrication technologies.
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Nanostructured layers of semiconducting metal oxides in gas sensors
Bartoš, Dušan ; Pytlíček, Zdeněk (oponent) ; Bendová, Mária (vedoucí práce)
This diploma thesis discusses the gas sensor preparation via anodic oxidation. It names sensor types, deals with the sensing principle of electrochemical sensors in detail and submits sensor parameters. It describes preparation technology and characterization technology methods. In the experimental part, it focuses on both the measurement methodology and the electrochemical oxygen sensor covered with titanium dioxide nanocolumns fabrication. Not the least it discusses acquired research results.
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Nanostructured layers of semiconducting metal oxides in gas sensors
Bartoš, Dušan ; Pytlíček, Zdeněk (oponent) ; Bendová, Mária (vedoucí práce)
This diploma thesis discusses the gas sensor preparation via anodic oxidation. It names sensor types, deals with the sensing principle of electrochemical sensors in detail and submits sensor parameters. It describes preparation technology and characterization technology methods. In the experimental part, it focuses on both the measurement methodology and the electrochemical oxygen sensor covered with titanium dioxide nanocolumns fabrication. Not the least it discusses acquired research results.
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