178 research outputs found
Aligned metal oxide nanotube arrays: key-aspects of anodic TiO2 nanotube formation and properties
Over the past ten years, self-aligned TiO2 nanotubes have attracted
tremendous scientific and technological interest due to their anticipated
impact on energy conversion, environment remediation and biocompatibility. In
the present manuscript, we review fundamental principles that govern the
self-organized initiation of anodic TiO2 nanotubes. We start with the
fundamental question: Why is self-organization taking place? We illustrate the
inherent key mechanistic aspects that lead to tube growth in various different
morphologies, such as rippled-walled tubes, smooth tubes, stacks and
bamboo-type tubes, and importantly the formation of double-walled TiO2
nanotubes versus single-walled tubes, and the drastic difference in their
physical and chemical properties. We show how both double- and single-walled
tube layers can be detached from the metallic substrate and exploited for the
preparation of robust self-standing membranes. Finally, we show how by
selecting the right growth approach to TiO2 nanotubes specific functional
features can be significantly improved, e.g., an enhanced electron mobility,
intrinsic doping, or crystallization into pure anatase at extremely high
temperatures can be achieved. This in turn can be exploited in constructing
high performance devices based on anodic TiO2 in a wide range of applications.Comment: from Nanoscale Horiz., 2016, Advance Articl
Aminated TiO2 nanotube as a Photoelectrochemical Water Splitting photoanode
The present work reports on the enhancement of TiO2 nanotubes
photoelectrochemical water splitting rate by decorating the nanostructure with
an amine layer in a hydrothermal process using diethylenetriamine (DETA). The
aminate coated TiO2 tubes show a stable improvement of the photoresponse in
both UV and visible light spectrum and under hydrothermal conditions, 4-fold
increase of the photoelectrochemical water splitting rate is observed. From
intensity modulated photocurrent spectroscopy (IMPS) measurements significantly
faster electron transport times are observed indicating a surface passivating
effect of the N-decoration.Comment: In Catalysis Today, Available online 21 July 201
Fabrication of TiO2 nanofibre photoelectrode for photoelectrochemical cells
The TiO2 nanofibres (NFs), prepared with the electrospinning method, acted as the photoanode in a photoelectrochemical cell (PEC) for hydrogen generation. The fabrication parameters of Ti/PVP (polyvinylpyrrolidone) fibres were determined with the field-emission scanning electron microscopy (FE-SEM) method. The structure and morphology of the TiO2 fibres were characterized by using X-ray diffraction (XRD), FE-SEM, transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HR-TEM). The average diameter of the TiO2 fibre is 132 ± 16 nm. A three-electrode potentiostat was used to study the photoelectrochemical properties of the photoanode. The density photocurrent reached the saturation value of 80 mA·cm–2 at 0.2 V under the irradiation of a Xenon lamp
Ultrasonic-Assisted Cathodic Plasma Electrolysis Approach for Producing of Graphene Nanosheets
In this chapter, we review on the production of graphene by ultrasonic-assisted cathodic plasma electrolysis approach which involves a combination process of conventional electrolysis and plasma at ambient pressure and moderate temperature. Firstly, we review on the techniques for electrochemical preparation of graphene. Then, we briefly describe plasma electrolysis approach for producing of graphene. The mechanism, advantages, and disadvantages of this technique are discussed in detail
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