A5070633848- Advanced Photocatalysis Techniques
- TiO2 Photocatalysis and Solar Cells
- Semiconductor materials and devices
- Electronic and Structural Properties of Oxides
- Copper-based nanomaterials and applications
- Polymer Surface Interaction Studies
- Electron and X-Ray Spectroscopy Techniques
- Molecular Junctions and Nanostructures
- Catalytic Processes in Materials Science
- Metal and Thin Film Mechanics
- Hydrogen embrittlement and corrosion behaviors in metals
- High-Temperature Coating Behaviors
- Semiconductor materials and interfaces
- Bone Tissue Engineering Materials
- Corrosion Behavior and Inhibition
- Metallurgical Processes and Thermodynamics
- Electrophoretic Deposition in Materials Science
- Gaze Tracking and Assistive Technology
- Electrocatalysts for Energy Conversion
- Marine Biology and Environmental Chemistry
- CO2 Reduction Techniques and Catalysts
- EEG and Brain-Computer Interfaces
- Muscle activation and electromyography studies
- Electrochemical Analysis and Applications
- Nanowire Synthesis and Applications
Tampere University
2008-2024
Amorphous titanium dioxide (a-TiO2) combined with an electrocatalyst has shown to be a promising coating for stabilizing traditional semiconductor materials used in artificial photosynthesis efficient photoelectrochemical solar-to-fuel energy conversion. In this study we report detailed analysis of two methods modifying undoped thin film atomic layer deposited (ALD) a-TiO2 without affect its performance water splitting reaction as protective photoelectrode coating. The are high-temperature...
Amorphous titania (am.-TiO2) has gained wide interest in the field of photocatalysis, thanks to exceptional disorder-mediated optical and electrical properties compared crystalline TiO2. Here, we study effects intrinsic Ti3+ nitrogen defects am.-TiO2 thin films via atomic layer deposition (ALD) chemistry tetrakis(dimethylamido)titanium(IV) (TDMAT) H2O precursors at growth temperatures 100–200 °C. X-ray photoelectron spectroscopy (XPS) computational analysis allow us identify structural...
Visually black, electrically leaky, amorphous titania (am-TiO2) thin films were grown by atomic layer deposition (ALD) for photocatalytic applications. Broad spectral absorbance in the visible range and exceptional conductivity are attributed to trapped Ti3+ film. Oxidation of upon heat treatment leads a drop conductivity, color change from black white, crystallization am-TiO2. ALD-grown TiO2, without any treatment, is subject dissolution alkaline photoelectrochemical conditions. The best...
The physicochemical properties of titanium dioxide (TiO2) depend strongly on the crystal structure. Compared to anatase, rutile TiO2 has a smaller bandgap, higher dielectric constant, and refractive index, which are desired for thin films in many photonic applications. Unfortunately, fabrication usually requires temperatures that too high (>400 °C, often even 600–800 °C) applications involving, e.g., temperature-sensitive substrate materials. Here, we demonstrate atomic layer deposition...
Abstract A straightforward solution-based method to modify the biofunctionality of stainless steel (SS) using heterobifunctional silane-polyethylene glycol (silane-PEG) overlayers is reported. Reduced nonspecific biofouling both proteins and bacteria onto SS further selective biofunctionalization modified surface were achieved. According photoelectron spectroscopy analyses, silane-PEGs formed less than 10 Å thick with close 90% coverage reproducible chemical compositions. Consequently,...
Dissolution of a platinum catalyst is major degradation mechanism fuel cells, but the exact reaction has remained unclear. Here, electrochemical ambient pressure X-ray photoelectron spectroscopy (EC-APXPS) was utilized to provide direct information on chemical species single-crystal Pt(111) electrode under extremely low pH conditions. Measurements were conducted using novel condensed electrolyte film cell applying work function measurement as loss-free probe for potential. We show that can...
Hybrid organic–inorganic interfaces are the key to functionalization of stainless steel (SS). We present a solution-based deposition method for fabricating uniform bimolecular organosilane monolayers on SS and show that their properties functionalities can be further developed through site-specific biotinylation. correlate molecular interface with its reactivity via surface sensitive synchrotron radiation mediated high-resolution photoelectron spectroscopy (HR-PES) chemical derivatization...
Thin organic coatings (TOC) or paints on hot dip galvanized steel (HDGS) improve the corrosion properties and create visually pleasing surfaces. Delamination of these leads to peeling paints. Hence, a novel method for improved adhesion HDGS surfaces is introduced. It shown how fabrication nanomolecular silane film as an interfacial layer between TOC paint improves in different pH regimes. Understanding behavior ultra-thin layers under differing crucial, subsequent have pHs. By varying...
The aim of this work was to model facial electromyography (fEMG) find optimal electrode positions for wearable human-computer interface system. system is a head cap developed in our institute and with it we can measure fEMG electro-oculogram (EOG). signals be used control the computer interface: gaze directions move cursor muscle activations correspond clicking. In very accurate 3D human modeling fEMG. four electrodes on forehead measuring frontalis corrugator muscles were defined. It...
Abstract Amorphous TiO 2 thin films have an insufficient chemical stability for photocatalytic applications. Annealing treatments induce crystallization improving the stability. However, crystalline structure is already predetermined by composition of amorphous phase. In this paper, we demonstrate that oxide defects, i.e., oxygen vacancies and Ti 3+ states, can be created O deficiency during ion-beam sputter deposition without affecting O/Ti ratio thus contains a variable degree under-...
Oxygen vacancies and Ti 3+ defects in the amorphous phase of TiO 2 predetermine vacuum annealing induced crystallization. Anatase, nanocrystalline rutile or mixed phases can be created by defect engineering without affecting O/Ti ratio.
Atomic layer deposited (ALD) TiO2 thin films have a wide range of applications in photonics which are, however, limited by the chemical instability amorphous as-deposited TiO2. Post-deposition annealing is required for improving performance inducing phase transitions and oxide defects. ALD precursor traces remaining TiO2film affect thermally-induced processes but understanding effect growth temperature on film as well weak. In this study 30 nm was grown Si wafer from...