Characterization and Photocatalytic Activity of Enhanced Copper-Silica-Loaded Titania Prepared via HydrothermalMethod

TiO2 nanopowder, loaded with SiO2 and Cu-SiO2, was prepared under both acidic and basic environments via the hydrothermal method. The morphology and structure of TiO2 were studied by XRD, TEM, and FT-IR. The photocatalytic activity of samples was studied by monitoring the degradation of methyl orange, using a UV-visible spectrophotometer. The effect of Ti/Si ratio, pH, and Cu2+ addition on the formation of TiO2 and its photocatalytic activity was investigated in detail. The results show that a large surface area and a high surface acidity were important factors to achieve good TiO2 performance. The presence of Ti-O-Si bonding enhanced surface acidity, which improved its ability to adsorb more hydroxyl radicals and increased its surface area. The addition of 0.1mol% concentration of Cu2+ and 25mol% SiO2 in TiO2 induced the formation of new states close to the conduction band, which narrowed the band gap energy and enhanced the photodegradation efficiency

Photoelectrochemical Performance of Smooth TiO 2

The formation of self-organized titanium dioxide (TiO2) nanotube arrays without bundling or clustering is essential for their high efficiency in photoelectrochemical (PEC) application. The present paper reports on the use of different temperatures to control the specific architecture of nanotube arrays and effective cleaning techniques to ensure the formation of clean TiO2 nanotube surface. The wall thickness of nanotube arrays could be controlled from 12.5 nm to 37.5 nm through different anodization temperature ranging from 10°C to 80°C. Furthermore, ultrasonic cleaning combined with acetone showed the high-ordered TiO2 nanotube arrays without morphological disorder, bundling, and microcrack problems. Based on the results obtained, a higher PEC response of 1 mA/cm2 and a photoconversion efficiency of 1.3% could be achieved using a wall thickness of 12.5 nm and defect-free TiO2 nanotube arrays for low charge transfer resistance

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

Titanium Dioxide Nanotube Arrays for Biomedical Implant Materials and Nanomedicine Applications

Nanotechnology has become a research hotspot to explore functional nanodevices and design materials compatible with nanoscale topography. Recently, titanium dioxide nanotube arrays (TNA) have garnered considerable interest as biomedical implant materials and nanomedicine applications (such as nanotherapeutics, nanodiagnostics and nanobiosensors). In bio-implants studies, the properties of TNA nanostructures could modulate diverse cellular processes, such as cell adhesion, migration, proliferation, and differentiation. Furthermore, this unique structure of TNA provides larger surface area and energy to regulate positive cellular interactions toward the mechanosensitivity activities. As for an advanced medical application, the TNA—biomolecular interactions knowledge are critical for further characterization of nanomaterial particularly in nanotherapeutic manipulation. Knowledge of these aspects will create opportunities for better understanding which may help researchers to develop better nanomaterial products to be used in medicine and health-line services

Ca(OH)2 nano-pods: investigation on the effect of solvent ratio on morphology and CO2 adsorption capacity

Ca(OH)2 nano-pods were synthesized through a precipitation method. Solvents such as ethanol/deionized water (DIW) and dimethylformamide (DMF)/deionized water (DIW) were used at different volume ratios to synthesize the samples. Various characterization techniques such as X-ray diffraction (XRD), filed emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM) and BET surface area analysis were employed to investigate the role of solvent on the crystallinity, morphology and surface area of Ca(OH)2. The solvent mixtures with a high volume of organic solvent (ethanol or DMF) acted as good capping agents to suppress the growth of Ca(OH)2 in the (1010) direction and induce anisotropic growth along the (0001) direction. A uniform pod like morphology was observed for the Ca(OH)2 sorbent synthesized using ethanol/DIW with a volume ratio of 78 ml/02 ml. Besides, the sorbents synthesized using ethanol/DIW showed good CO2 adsorption capacity and high surface area when compared to that of DMF/DIW

Factor Affecting Geometry of TiO2 Nanotube Arrays (TNAs) in Aqueous and Organic Electrolyte

TiO2 nanotube arrays (TNA) have attracted scientific interest due to the combination of functional material properties with controllable nanostructure. Superior properties of TNA, including vectorial pathway of e− transport, minimized e− recombination, and high specific surface area render them as the most promising candidate for environment remediation, energy conversion and biocompatibility applications. The superior properties and efficacy of the TNA in various applications influenced by structural characteristics such as pore size, length and wall thickness. Therefore in this chapter the effect of various electrochemical parameters such as applied voltage, anodization time, electrolyte composition on the formation of controlled dimension of TNA in aqueous and organic electrolytes are reviewed

Physical and electrical characteristics of NiFe thin films using ultrasonic assisted pulse electrodeposition

Nickel iron (NiFe) thin films were prepared on the copper substrate by ultrasonic assisted pulse electrodeposition under galvanostatic mode. Careful control of the thin films deposition is essential as the electrical properties of the films could be greatly affected, particularly if low quality films are produced. The preparation of NiFe/Cu thin films was aimed to reduce the grain size of NiFe particles, surface roughness and electrical resistivity of the copper substrates. Various parameters were systematically studied including current magnitude, deposition time and ultrasonic bath temperature. The optimized conditions to obtain NiFe permalloy, which subsequently applied to all investigated samples, were found at a current magnitude of 70 mA deposited for a duration of 2 min under ultrasonic bath temperature of 27 °C. The composition of NiFe permalloy was as close as Ni 80.71% and Fe 19.29% and the surface roughness was reduced from 12.76 nm to 2.25 nm. The films electrical resistivity was decreased nearly sevenfold from an initial value of 67.32 μΩ cm to 9.46 μΩ cm

Cellular Homeostasis and Antioxidant Response in Epithelial HT29 Cells on Titania Nanotube Arrays Surface

Cell growth and proliferative activities on titania nanotube arrays (TNA) have raised alerts on genotoxicity risk. Present toxicogenomic approach focused on epithelial HT29 cells with TNA surface. Fledgling cell-TNA interaction has triggered G0/G1 cell cycle arrests and initiatesDNA damage surveillance checkpoint, which possibly indicated the cellular stress stimuli. A profound gene regulation was observed to be involved in cellular growth and survival signals such as p53 and AKT expressions. Interestingly, the activation of redox regulator pathways (antioxidant defense) was observed through the cascade interactions of GADD45, MYC, CHECK1, and ATR genes.These mechanisms furnish to protect DNA during cellular division from an oxidative challenge, set in motion with XRRC5 and RAD50 genes for DNA damage and repair activities. The cell fate decision on TNA-nanoenvironment has been reported to possibly regulate proliferative activities via expression of p27 and BCL2 tumor suppressor proteins, cogent with SKP2 and BCL2 oncogenic proteins suppression. Findings suggested that epithelial HT29 cells on the surface of TNA may have a positive regulation via cell-homeostasis mechanisms: a careful circadian orchestration between cell proliferation, survival, and death. This nanomolecular knowledge could be beneficial for advanced medical applications such as in nanomedicine and nanotherapeutics