A Novel Solar Driven Photocatalyst: Well-Aligned Anodic WO3 Nanotubes

Well-aligned anodic tungsten trioxide (WO3) nanotubes were successfully synthesized by anodization of W foil at 40V in a bath with electrolyte composed of 1M of sodium sulphate (Na2SO4) and 0.5 wt% ammonium fluoride (NH4F). The effect of electrochemical anodization times on the formation mechanism of anodic WO3 nanotubular structure was investigated. It was found that minimumof 15 min is required for completing transformation fromWfoil toWO3 nanotubular structurewith an average diameter of 50nmand length of 500 nm.Thephotocatalytic ability of the sampleswas evaluated by degradation of methyl blue (MB) dye.Theresults indicate that the surface morphology of anodicWO3 affected the photocatalyticMBdegradation significantly under solar illumination

Vapor-phase hydrothermal synthesis of rutile TiO2 nanostructured film with exposed pyramid-shaped (111) surface and superiorly photoelectrocatalytic performance

Rutile TiO2 nanostructured film with exposed pyramid-shaped (111) surface was successfully fabricated using metal titanium foil as substrate through a facile vapor-phase hydrothermal method. The fabricated rutile TiO2 film was composed of vertically aligned rod-like structures with diameters ranged from 400 to 700 nm and thickness of ca. 2.0 孮 The obtained rutile TiO2 film as photoanode exhibited excellent photoelectrocatalytic activity toward water oxidation and rhodamine B decolorization under UV illumination, which was more than 3.5 and 1.2 times of that obtained by highly ordered anatase TiO2 nanotube array film photoanode under the same experimental conditions, respectively. The excellent photoelectrocatalytic performance of the rutile TiO2 film photoanode could be due to the superior photoelectron transfer property and the high oxidative capability of {111} crystal facets. The superior photoelectron transfer capability of the photoanodes was manifested by the inherent resistance (R0) of the photoanodes using a simple photoelectrochemical method. The calculated R0 values were 50.5 and 86.2 O for the rutile TiO2 nanostructured film and anatase TiO2 nanotube array film, respectively. Lower R0 value of the rutile TiO2 photoanode indicated a superior photoelectron transfer capability owing to good single crystal property of the rod-like rutile nanostructure. Almost identical valence band level (1.94 eV) of the rutile TiO2 nanostructured film and anatase TiO2 nanotube array film (meaning a similar oxidation capability) further confirmed the significant role of photoelectron transfer capability and exposed high-energy {111} crystal facets for improved photoelectrocatalytic performance of the rutile TiO2 nanostructured film photoanode.No Full Tex

The control of mesenchymal stromal cell osteogenic differentiation through modified surfaces

Stem cells continue to receive widespread attention due to their potential to revolutionise treatments in the fields of both tissue engineering and regenerative medicine. Adult stem cells, specifically mesenchymal stromal cells (MSCs) play a vital role in the natural events surrounding bone healing and osseointegration through being stimulated to differentiate along their osteogenic linage and in doing so, form new cortical and trabecular bone tissue. Understanding how to control, manipulate and enhance the intrinsic healing events modulated through osteogenic differentiation of MSCs by the use of modified surfaces and biomaterials, could potentially advance the fields of both orthopaedics and dentistry. This could be by either using surface modification to generate greater implant stability and more rapid healing following implantation, or the stimulation of MSCs ex-vivo for re-implantation. This review aims to gather publications targeted at promoting, enhancing and controlling the osteogenic differentiation of MSCs through biomaterials, nanotopographies and modified surfaces for use in implant procedures

Modification of Mixed Structure Tio2 Nanoporous-nanotube Arrays with Cds Nano Particle and Their Photo Electro Chemicalproperties

MODIFICATION OF MIXED STRUCTURE TiO2 NANOPOROUS-NANOTUBE ARRAYS WITH CdS NANO PARTICLE AND THEIR PHOTO ELECTRO CHEMICALPROPERTIES. In thiswork, a mixed structure TiO2 with a top nanoporous layer and an underneath highly ordered nanotube arrays layer (TNPs-NTAs) were prepared by anodic oxidation of Ti foil under controlled anodization time in an electrolyte containing fluoride ion,water and ethylene glycol. CdS nanoparticles (NPs) was deposited onto the mixed structure of TiO2 by Successive Ionic Layer Adsorption and Reaction (SILAR) with an aim toward tuning the photoelectrochemical performance to visible region. Themorphology, elemental composition, crystal structure, optical properties and photoelectrochemical performance of TNPs-NTs and CdS modified (CdS/TNP-NTAs) samples were characterized by Field Emisi Scanning Electron Microscope (FESEM), Electron Dispersive Spectroscopy (EDS), X-Ray Diffractometer (XRD), Diffuse Reflactance Spectroscopy (DRS) and electrochemical working station respectively. The results indicate that CdS nanoparticles uniformly decorated on top of surface and inner wall of TNPs-NTs sample. No clogging of CdS-NP at the mouth TNPs-NTAs was observed. The CdS/TNP-NTs show an increasing in the visible light adsorption and photocurrent response. Under white light illumination (9.93 mW/cm2), we found that the CdS/TNPs-NTAs have an optimum photocurrent density of 1.16 mA/cm2 , corresponding to energy photoconversion efficiency of 9.75%, which is 7 times higher than that of the bare TiO2 (TNPs-NTAs). The increase of photocurrent is attributed to the enhancement of charge separation efficiency and improved electron transport

TiO2 Nanotubes on ti dental implant. Part 3: Electrochemical behavior in Hank’s solution of titania nanotubes formed in ethylene glycol

Anodic oxidation is an easy and cheap surface treatment to form nanostructures on the surface of titanium items for improving the interaction between metallic implants and the biological environment. The long-term success of the devices is related to their stability. In this work, titanium nanotubes were formed on a dental screw, made of titanium CP2, through an anodization process using an “organic” solution based on ethylene glycol containing ammonium fluoride and water. Then, the electrochemical stability in the Hank’s solution of these “organic” nanotubes has been investigated for 15 days and compared to that of titanium nanotubes on a similar type of sample grown in an inorganic solution, containing phosphoric and hydrofluoridric acids. Morphological and crystallographic analysis were performed by using scanning electron microscopy (SEM) and X-Ray diffractometry (XRD) tests. Electrochemical measurements were carried out to study the stability of the nanotubes when are in contact with the biological environment. The morphological measurements revealed long nanotubes, small diameters, smooth side walls, and a high density of “organic” nanotubes if compared to the “inorganic” ones. XRD analysis demonstrated the presence of rutile form. An appreciable electrochemical stability has been revealed by Electrochemical Impedance Spectroscopy (EIS) analysis, suggesting that the “organic” nanotubes are more suitable for biomedical devices

In situ synthesis of hydroxyapatite-grafted titanium nanotube composite

The present study is an investigation to demonstrate the effectiveness of insitu approach in the synthesis of hydroxyapatite-grafted titanium nanotube composite (HA-TNT). This method involves combining the process of HA sol–gel and rapid breakdown anodisation of titanium in a novel solution consisting of NaCl and N3PO4. This new synthesis approach produced a uniform dispersion of Anatase and Rutile phases of TiO2 nanotubes with minimal agglomeration in the matrix of crystalline HA. The characterisation of homogenised HA-TNT composite was investigated via field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), transmission electron microscope (TEM) and X-ray diffraction (XRD). FESEM and TEM images indicated the nanostructure of composite with TiO2 nanotube diameter of approximately 10 nm. XRD and EDS analyses confirmed the formation of HA crystalline with the Ca/P ratio of 1.58 and formation of Anatase and Rutile phase of TiO2 nanotubes

Room Temperature Processing of TiOx Electron Transporting Layer for Perovskite Solar Cells

In order to realize high-throughput roll-to-roll manufacturing of flexible perovskite solar cells, low temperature processing of all device component must be realized. However, the most commonly used electron transporting layer is based on TiO2 thin films processed at high temperature (>450C). Here, we demonstrate room temperature solution processing of TiOx layer that performs as well as the high temperature TiO2 layer in perovskite solar cells, as evidenced by a champion solar cell efficiency of 16.3%. Using optical spectroscopy, electrical measurements and X-ray diffraction, we show that the room temperature processed TiOx is amorphous with organic residues and yet their optical and electrical properties are on par with the high temperature TiO2. Flexible perovskite solar cells, that employ the room temperature TiOx layer, with power conversion efficiency of 14.3% are demonstrated

Towards Visible Light Hydrogen Generation: Quantum Dot-Sensitization via Efficient Light Harvesting of Hybrid-TiO2

We report pronounced enhancement of photoelectrochemical hydrogen generation of a quantum dot-sensitized hybrid-TiO2 (QD/H-TiO2) electrode that is composed of a mesoporous TiO2 layer sandwiched by a double sided energy harvesting layer consisting of a surface-textured TiO2 inverse opals layer on the bottom and a patterned mesoporous TiO2 layer on the top. CdSe/H-TiO2 exhibits a maximum photocurrent density of similar to 16.2 mA/cm(2), which is 35% higher than that of the optimized control sample (CdSe/P25), achieved by matching of the bandgap of quantum dot-sensitization with the wavelength where light harvesting of H-TiO2 is observed. Furthermore, CdSe/H-TiO2 under filtered exposure conditions recorded current density of similar to 14.2 mA/cm(2), the greatest value in the visible range. The excellent performance of the quantum dot-sensitized H-TiO2 suggests that alteration of the photoelectrodes to suitable nanostructures with excellent light absorption may offer optimal strategies for attaining maximum efficiency in a variety of photoconversion systems.open3

Development of 3D PCL microsphere/TiO\u3csub\u3e2\u3c/sub\u3e nanotube composite scaffolds for bone tissue engineering

In this research, the three dimensional porous scaffolds made of a polycaprolactone (PCL) microsphere/TiO2 nanotube (TNT) composite was fabricated and evaluated for potential bone substitute applications. We used a microsphere sintering method to produce three dimensional PCL microsphere/TNT composite scaffolds. The mechanical properties of composite scaffolds were regulated by varying parameters, such as sintering time, microsphere diameter range size and PCL/TNT ratio. The obtained results ascertained that the PCL/TNT (0.5 wt%) scaffold sintered at 60 °C for 90 min had the most optimal mechanical properties and an appropriate pore structure for bone tissue engineering applications. The average pore size and total porosity percentage increased after increasing the microsphere diameter range for PCL and PCL/TNT (0.5 wt%) scaffolds. The degradation rate was relatively high in PCL/TNT (0.5 wt%) composites compared to pure PCL when the samples were placed in the simulated body fluid (SBF) for 6 weeks. Also, the compressive strength and modulus of PCL and PCL/TNT (0.5 wt%) composite scaffolds decreased during the 6 weeks of storage in SBF. MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay and alkaline phosphates (ALP) activity results demonstrated that a generally increasing trend in cell viability was observed for PCL/TNT (0.5 wt%) scaffold sintered at 60 °C for 90 min compared to the control group. Eventually, the quantitative RT-PCR data provided the evidence that the PCL scaffold containing TiO2 nanotube constitutes a good substrate for cell differentiation leading to ECM mineralization

Combined Structural, Chemometric, and Electrochemical Investigation of Vertically Aligned TiO2 Nanotubes for Na-ion Batteries

In the challenging scenario of anode materials for sodium-ion batteries, TiO2 nanotubes could represent a winning choice in terms of cost, scalability of the preparation procedure, and long-term stability upon reversible operation in electrochemical cells. In this work, a detailed physicochemical, computational, and electrochemical characterization is carried out on TiO2 nanotubes synthesized by varying growth time and heat treatment, viz. the two most significant experimental parameters during preparation. A chemometric approach is proposed to obtain a concrete and solid multivariate analysis of sodium battery electrode materials. Such a statistical approach, combined with prolonged galvanostatic cycling and density functional theory analysis, allows identifying anatase at high growth time as the TiO2 polymorph of choice as an anode material, thus creating a benchmark for sodium-ion batteries, which currently took the center stage of the research in the field of energy storage systems from renewables