Enhancement of biocompatibility of anodic nanotube structures on biomedical Ti-6Al-4V alloy via ultrathin TiO coatings.

This work aims to describe the effect of the surface modification of TiO nanotube (TNT) layers on Ti-6Al-4V (TiAlV) alloy by ultrathin TiO coatings prepared via Atomic Layer Deposition (ALD) on the growth of MG-63 osteoblastic cells. The TNT layers with two distinctly different inner diameters, namely ∼15 nm and ∼50 nm, were prepared via anodic oxidation of the TiAlV alloy. Flat, i.

Ultrathin TiO Coatings via Atomic Layer Deposition Strongly Improve Cellular Interactions on Planar and Nanotubular Biomedical Ti Substrates.

This work aims to investigate the chemical and/or structural modification of Ti and Ti-6Al-4V (TiAlV) alloy surfaces to possess even more favorable properties toward cell growth. These modifications were achieved by (i) growing TiO nanotube layers on these substrates by anodization, (ii) surface coating by ultrathin TiO atomic layer deposition (ALD), or (iii) by the combination of both. In particular, an ultrathin TiO coating, achieved by 1 cycle of TiO ALD, was intended to shade the impurities of F- and V-based species in tested materials while preserving the original structure and morphology.

Enhanced CO Functionality on Carbon Papers Ensures Lowering Nucleation Delay of ALD for Ru towards Unprecedented Alkaline HER Activity.

The success in lowering the nucleation delay for Atomic Layer Deposition (ALD) of Ru on carbon surfaces is mitigated by constructive pretreatments resulting enhancement of CO functionality. Treatment of the carbon papers (CP) allowed Ru species deposition for minimum number of ALD cycles (25 cycles) with good conformality. The development of electrocatalysts from single atoms to nanoparticles (NPs) on conductive supports with low metal loadings, thus improving performance, is essential in electrocatalysis.

Gigahertz-Based Visible Light Detection Enabled via CdS-Coated TiO Nanotube Layers.

Detection of visible light is a key component in material characterization techniques and often a key component of quality or purity control analyses for health and safety applications. Here in this work, to enable visible light detection at gigahertz frequencies, a planar microwave resonator is integrated with high aspect ratio TiO nanotube (TNT) layer-sensitized CdS coating using the atomic layer deposition (ALD) technique. This unique method of visible light detection with microwave-based sensing improves integration of the light detection devices with digital technology.

2D FeS Nanosheets by Atomic Layer Deposition: Electrocatalytic Properties for the Hydrogen Evolution Reaction.

2-dimensional FeS nanosheets of different sizes are synthesized by applying different numbers of atomic layer deposition (ALD) cycles on TiO nanotube layers and graphite sheets as supporting materials and used as an electrocatalyst for the hydrogen evolution reaction (HER). The electrochemical results confirm electrocatalytic activity in alkaline media with outstanding long-term stability (>65 h) and enhanced catalytic activity, reflected by a notable drop in the initial HER overpotential value (up to 26 %). By using a range of characterization techniques, the origin of the enhanced catalytic activity was found to be caused by the synergistic interplay between in situ morphological and compositional changes in the 2D FeS nanosheets during HER.

Deposition of MoSe flakes using cyclic selenides.

The currently limited portfolio of volatile organoselenium compounds used for atomic layer deposition (ALD) has been extended by designing and preparing a series of four-, five- and six-membered cyclic silylselenides. Their fundamental properties were tailored by alternating the ring size, the number of embedded Se atoms and the used peripheral alkyl chains. In contrast to former preparations based on formation of sodium or lithium selenides, the newly developed synthetic method utilizes a direct and easy reaction of elemental selenium with chlorosilanes.

Removal of Ibuprofen from Water by Different Types Membranes.

Ibuprofen separation from water by adsorption and pertraction processes has been studied, comparing 16 different membranes. Tailor-made membranes based on Matrimid, Ultem, and diaminobenzene/diaminobenzoic acid with various contents of zeolite and graphene oxide, have been compared to the commercial polystyrene, polypropylene, and polydimethylsiloxane polymeric membranes. Experimental results revealed lower ibuprofen adsorption onto commercial membranes than onto tailor-made membranes (10-15% compared to 50-70%).

ALD coating of centrifugally spun polymeric fibers and postannealing: case study for nanotubular TiO photocatalyst.

This work describes the synthesis of highly photocatalytically active TiO tubes (TiTBs) by combining centrifugal spinning and atomic layer deposition (ALD). Poly(vinyl pyrrolidone) (PVP) fibers were first produced by centrifugal spinning and subsequently coated with TiO with various film thicknesses in a fluidized bed ALD reactor. After annealing of the TiO ALD coated PVP fibers, TiO tubes (TiTBs) with excellent textural properties and diameters in the range from approx.

Organoselenium Precursors for Atomic Layer Deposition.

Organoselenium compounds with perspective application as Se precursors for atomic layer deposition have been reviewed. The originally limited portfolio of available Se precursors such as HSe and diethyl(di)selenide has recently been extended by bis(trialkylsilyl)selenides, bis(trialkylstannyl)selenides, cyclic selenides, and tetrakis(,-dimethyldithiocarbamate)selenium. Their structural aspects, property tuning, fundamental properties, and preparations are discussed.

Chiral Templating of Polycarbonate Membranes by Pinene Using the Modified Atomic Layer Deposition Approach.

In this article, chiral templating of a polycarbonate (PC) membrane by (-)-α-pinene using the atomic layer deposition (ALD) approach is investigated. The templating with the enantiomer of (-)-α-pinene, used as a case compound, was performed either on the original commercial PC membrane or on the PC membrane with a beforehand deposited AlO layer. The efficiency of the templating was assessed by a difference in the membrane ability to adsorb/absorb (-)-α-pinene, (+)-α-pinene, and their racemic mixture, using a very sensitive gas sorption analyzer.

Thin TiO Coatings by ALD Enhance the Cell Growth on TiO Nanotubular and Flat Substrates.

The present work exploits Ti sheets and TiO nanotube (TNT) layers and their surface modifications for the proliferation of different cells. Ti sheets with a native oxide layer, Ti sheets with a crystalline thermal oxide layer, and two kinds of TNT layers (prepared via electrochemical anodization) with a defined inner diameter of 12 and 15 nm were used as substrates. A part of the Ti sheets and the TNT layers was additionally coated by thin TiO coatings using atomic layer deposition (ALD).

Atomic Layer Deposition of SnO-Coated Anodic One-Dimensional TiO Nanotube Layers for Low Concentration NO Sensing.

The continuous emission of nitrous oxides contributes to the overall air pollution and deterioration of air quality. In particular, an effective NO sensor capable of low concentration detection for continuous monitoring is demanded for safety, health, and wellbeing. The sensing performance of a metal oxide-based sensor is predominantly influenced by the availability of surface area for O adsorption and desorption, efficient charge transport, and size or thickness of the sensing layer.

TiO Nanotube Layers Decorated with AlO/MoS/AlO as Anode for Li-ion Microbatteries with Enhanced Cycling Stability.

TiO nanotube layers (TNTs) decorated with AlO/MoS/AlO are investigated as a negative electrode for 3D Li-ion microbatteries. Homogenous nanosheets decoration of MoS, sandwiched between AlO coatings within self-supporting TNTs was carried out using atomic layer deposition (ALD) process. The structure, morphology, and electrochemical performance of the AlO/MoS/AlO-decorated TNTs were studied using scanning transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and chronopotentiometry.

Cyclic Silylselenides: Convenient Selenium Precursors for Atomic Layer Deposition.

Three cyclic silylselenides were prepared in a straightforward manner. Property tuning has been achieved by varying the ring size and the number of embedded selenium atoms. All silylselenides possess improved resistance towards moisture and oxidation as well as high thermal robustness and sufficient volatility with almost zero residues.

2D MoS nanosheets on 1D anodic TiO nanotube layers: an efficient co-catalyst for liquid and gas phase photocatalysis.

One-dimensional TiO nanotube layers with different dimensions were homogeneously decorated with 2D MoS nanosheets via atomic layer deposition and employed for liquid and gas phase photocatalysis. The 2D MoS nanosheets revealed a high amount of exposed active edge sites and strongly enhanced the photocatalytic performance of TiO nanotube layers.

TiO ALD Coating of Amorphous TiO Nanotube Layers: Inhibition of the Structural and Morphological Changes Due to Water Annealing.

The present work presents a strategy to stabilize amorphous anodic self-organized TiO nanotube layers against morphological changes and crystallization upon extensive water soaking. The growth of needle-like nanoparticles was observed on the outer and inner walls of amorphous nanotube layers after extensive water soakings, in line with the literature on water annealing. In contrary, when TiO nanotube layers uniformly coated by thin TiO using atomic layer deposition (ALD) were soaked in water, the growth rates of needle-like nanoparticles were substantially reduced.

Spaced TiO Nanotubes Enable Optimized Pt Atomic Layer Deposition for Efficient Photocatalytic H Generation.

In the present work, we report the use of TiO nanotube (NT) layers with a regular intertube spacing that are decorated by Pt nanoparticles through the atomic layer deposition (ALD) of Pt. These Pt-decorated spaced (SP) TiO NTs are subsequently explored for photocatalytic H evolution and are compared to classical close-packed (CP) TiO NTs that are also decorated with various amounts of Pt by using ALD. On both tube types, by varying the number of ALD cycles, Pt nanoparticles of different sizes and areal densities are formed, uniformly decorating the inner and outer walls from tube top to tube bottom.

A 1D conical nanotubular TiO/CdS heterostructure with superior photon-to-electron conversion.

Herein, a new strategy to efficiently harvest photons in solar cells is presented. A solar cell heterostructure is put forward, based on a 1D conical TiO2 nanotubular scaffold of high aspect ratio, homogenously coated with a thin few nm layer of CdS light absorber using atomic layer deposition (ALD). For the first time, a large variety of conical nanotube layers with a huge span of aspect ratios was utilized and ALD was used for the preparation of a uniform CdS coating within the entire high surface area of the TiO2 nanotubes.

Ideally Hexagonally Ordered TiO Nanotube Arrays.

Ideally hexagonally ordered TiO nanotube layers were produced through the optimized anodization of Ti substrates. The Ti substrates were firstly covered with a TiN protecting layer prepared through atomic layer deposition (ALD). Pre-texturing of the TiN-protected Ti substrate on an area of 20×20 μm was carried out by focused ion beam (FIB) milling, yielding uniform nanoholes with a hexagonal arrangement throughout the TiN layer with three different interpore distances.

ALD AlO-Coated TiO Nanotube Layers as Anodes for Lithium-Ion Batteries.

The utilization of the anodic TiO nanotube layers, with uniform AlO coatings of different thicknesses (prepared by atomic layer deposition, ALD), as the new electrode material for lithium-ion batteries (LIBs), is reported herein. Electrodes with very thin AlO coatings (∼1 nm) show a superior electrochemical performance for use in LIBs compared to that of the uncoated TiO nanotube layers. A more than 2 times higher areal capacity is received on these coated TiO nanotube layers (∼75 vs 200 μAh/cm) as well as higher rate capability and coulombic efficiency of the charging and discharging reactions.

CdS-coated TiO nanotube layers: downscaling tube diameter towards efficient heterostructured photoelectrochemical conversion.

Herein, a novel photoelectrochemical heterostructure based on TiO nanotube layers uniformly coated by a CdS thin layer (using ALD) is presented. Downscaling the nanotube diameter (from 95 to 35 nm) resulted in a 2-fold enhancement of the UV and Vis light photocurrents. Further photocurrent improvement resulted from the prior annealing of the TiO nanotube layers from 300 to 600 °C.

Electrochemical Infilling of CuInSe within TiO Nanotube Layers and Subsequent Photoelectrochemical Studies.

Anodic self-organized TiO nanotube layers (with different aspect ratios) were electrochemically infilled with CuInSe nanocrystals with the aim to prepare heterostructures with a photoelectrochemical response in the visible light. The resulting heterostructure assembly was confirmed by field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). High incident photon-to-electron conversion efficiency values exceeding 55% were obtained in the visible-light region.

Atomic Layer Deposition AlO Coatings Significantly Improve Thermal, Chemical, and Mechanical Stability of Anodic TiO Nanotube Layers.

We report on a very significant enhancement of the thermal, chemical, and mechanical stability of self-organized TiO nanotubes layers, provided by thin AlO coatings of different thicknesses prepared by atomic layer deposition (ALD). TiO nanotube layers coated with AlO coatings exhibit significantly improved thermal stability as illustrated by the preservation of the nanotubular structure upon annealing treatment at high temperatures (870 °C). In addition, a high anatase content is preserved in the nanotube layers against expectation of the total rutile conversion at such a high temperature.

Atomic Layer Deposition for Coating of High Aspect Ratio TiO Nanotube Layers.

We present an optimized approach for the deposition of AlO (as a model secondary material) coating into high aspect ratio (≈180) anodic TiO nanotube layers using the atomic layer deposition (ALD) process. In order to study the influence of the diffusion of the AlO precursors on the resulting coating thickness, ALD processes with different exposure times (i.e.

A light-controlled resistive switching memory.

Sketch of the configuration of a light-controlled resistive switching memory. Light enters through the Al(2) O(3) uncovered surface and reaches the optically active p-Si substrate, where carriers are photogenerated and subsequently injected in the Al(2) O(3) layer when a suitable voltage pulse is applied. The resistance of the Al(2) O(3) can be switched between different non-volatile states, depending on the applied voltage pulse and on the illumination conditions.