Nitrogen-doped TiO2 nanotube array films with enhanced photocatalytic activity under various light sources

Zhang

Journal of Alloys and Compounds

et al. 2016

164

a b s t r a c t N-doped TiO 2 nanowire/N-doped graphene (NeTiO 2 /NG) heterojunctions are fabricated by a simple hydrothermal method in a solution containing urea. In this hybrid structure, a three-dimensional hybrid photocatalyst was fabricated by using one-dimensional N-doped TiO 2 nanowires penetrating through twodimensional graphene nanosheets. Compared with TiO 2 nanowire/graphene and N-doped TiO 2 nanowire/ graphene composites, the NeTiO 2 /NG heterostructures demonstrate a better photocatalytic performance for the degradation of methylene blue under visible light irradiations, as well as displaying a better recyclability. It is found that the nitrogen atoms originated from the decomposition of urea were not only entered into the lattice of TiO 2 nanowires but also doped into the skeleton of graphene nanosheets. Results show that N doping expands the visible light absorption region of TiO 2 , and N-doped graphene additionally improves the separation and transportation of photogenerated electronehole pairs plus generating a higher photocurrent, which plays a critical role for enhancing the photocatalytic activity.

Section: Possible Photocatalytic Mechanismmentioning

confidence: 99%

Hydrothermal synthesis of N-doped TiO2 nanowires and N-doped graphene heterostructures with enhanced photocatalytic properties

Zhang

Journal of Alloys and Compounds

et al. 2016

164

J Solid State Electrochem

“…Therefore, several approaches have been proposed to modify the optical and the electrical properties of TiO 2 [17,18]. Among those, doping with both metals such as Cu, Co., V, Fe, Cr [14,[19][20][21][22][23][24][25] and nonmetals like N, H, C [26][27][28][29][30][31][32][33] aims to shift the absorption of TiO 2 from the UV region to the visible region and the effective utilization of the solar light spectrum.…”

Section: Introductionmentioning

confidence: 99%

Facile one-step process for synthesis of vertically aligned cobalt oxide doped TiO2 nanotube arrays for solar energy conversion

Ali

Ismail

Mekewi

et al. 2015

Vertically aligned cobalt oxide doped TiO 2 nanotube arrays (Co.-oxide TNTAs) were synthesized via one potanodic oxidation of pure titanium substrate in the presence of ammonium fluoride and cobalt salt. After subsequent annealing in air the produced arrays were in the tubular structure and doped with Co.-oxide. The designed TNTAs and Co.-oxide TNTAs were tested as photoanode electrodes in a photoelectrochemical cell. Energy dispersive X-ray (EDX) spectroscopy confirms the incorporation of Co. in the doped TNTAs. The Tauc plots estimated from UV-Vis diffuse reflectance spectra displayed that the insertion of the optimum amount of Co.-oxide leads to a decrease in the band gap of TiO 2 from 3.2 to 2.9 eV. The influences of various cobalt salt concentrations in the electrolyte solution (5, 10, 15, 20 and 25 mM) on the morphology were studied. The evaluation of the photocurrent and photoconversion efficiency was performed for all the fabricated electrodes. Morphological studies illustrated that the addition of cobalt salt with small concentration has no an obvious effect on the ordered tubular structure of TNTAs, whereas, at higher concentrations the tubular structure was partially collapsed. Co.-oxide enhanced the photoconversion efficiency of TNTA electrode by 30 % at optimum concentration under 110 mW/cm 2 solar simulator illumination.

Smart Drug Delivery System

“…TiO 2 nanotubes have been studied predominantly in the field of photocatalysis [74][75][76], solar cells [77], and biomedical engineering [78][79][80], because of their excellent photocatalytic activity and biocompatibility. In addition, the high surface area and unique shape of TiO 2 nanotubes make them a promising option for application in drug delivery systems.…”

Section: Light-sensitive Drug Deliverymentioning

confidence: 99%

Smart Drug Delivery Strategies Based on Porous Nanostructure Materials

Wang¹,

Huang²,

Lai³

2016

The control of drug delivery can have a great effect on its efficacy. An optimum concentration range of drugs can play a significant role in the human body, and it can cause harm to humans when it exceeds the range of the drug concentration. Recently, a variety of drug deliveries and their targeted systems have been studied to minimize drug loss and maximize the amount of drug accumulated in the required area, thus increasing drug bioavailability. In addition, we should especially consider the prevention of its harmful side-effects in the human body. Innovative drug delivery systems based on biodegradable, natural or synthetic polymers, micro-or nano-particles, lipoproteins, micelles, TiO 2 nanotube arrays (TNTs), nanoporous anodic aluminum oxide (AAO), and so on were developed, which combined magnetic targeting and stimulus-responsive in drug delivery systems. The composition of delivery carriers and the stimulus-responsive elements proved stimulus-responsive drug release as a smart drug delivery system.