Porous V2O5/TiO2 nanoheterostructure films with different atomic ratios of Ti/V (4:1, 2:1, 1:1, and 1:2) were synthesized by a sparking method for the first time. The sparking method, which is a simple and cost-effective process, can synthesize highly porous and composite films in one step. Field-emission scanning electron microscope (FE-SEM) images revealed the porosity morphology of all prepared samples. V2O5/TiO2 nanoheterostructure films were confirmed by Raman spectroscopy, high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS). The secondary particle size and band gap of the samples were highly correlated to the V2O5 proportion, resulting in enhanced visible-light absorbance. V2O5/TiO2 nanoheterostructure films at an atomic ratio of 1:1 showed the highest photocatalytic performance, which improved the degradation rate up to 24% compared to pure TiO2 film. It is believed that the formed nanoheterostructure and greater portion of V4+ ions are reflected by this ratio.

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Copper–iron (Cu–Fe) oxide composite films were successfully deposited on quartz substrate by a facile sparking process. The nanoparticles were deposited on the substrate after sparking off the Fe and Cu tips with different ratios and were then annealed at different temperatures. The network particles were observed after annealing the film at 700 °C. Meanwhile, XRD, XPS and SAED patterns of the annealed films at 700 °C consisted of a mixed phase of CuO, γ-Fe2O3, CuFe2O4 and CuFe2O. The film with the lowest energy band gap (Eg) of 2.56 eV was observed after annealing at 700 °C. Interestingly, the optimum ratio and annealing temperature show the photocatalytic activity under visible light higher than 20% and 30% compare with the annealed TiO2 at 500 and 700 °C, respectively. This is a novel photocatalyst which can be replaced TiO2 for photocatalytic applications in the future.

Stretchable and compressible strain sensors play an essential role in various fields with uses ranging from automotive components to medical devices. This study reports on the fabrication and characteristics of stretchable strain and pressure sensors constructed using a carbon nanotube and graphene composite. The sensors were used for gait analysis, an important step in the diagnosis and management of movement disorders. The stretchable and compressible strain sensors were used to measure peak knee sagittal angles and forces under the feet when walking. Gait analysis is usually performed within a laboratory. However, in this research we propose a shift to gait assessments conducted via long-term daily monitoring using wearable devices.

We have used an external electric field to increase both the uniformity and deposition rate of TiO2 films. The experiment is carried out by sparking-off titanium wires with a high dc voltage of 1 kV (field int = 10 kV/cm) and a limited current of 3 mA. The external electric fields ( ext) of 3, 6, and 9 kV/cm were applied to the sparking system for 1-5 hours. The as-deposited film morphology was characterized by scanning electron microscopy. The results clearly show that the films are only deposited on the external electric field area. Furthermore, the deposition rate of the films increased from 40.7% to 77.8% in the presence of the external electric field of 9 kV/cm. The effects of an external electric field on both the deposition rate and uniformity of films are investigated and described. K e y w o r d s: TiO2 film, sparking process, external electric fields.

Hexagonal tungsten trioxide (WO 3 ) layers are grown on indium tin oxide (ITO) substrates using a novel spark deposition system. The effects of deposition time, substrate temperature, and oxygen (O 2 ) flow rate through the chamber on the structural and morphological characteristics as well as the electrochemical response of the layers are examined. It is found that a deposition temperature of 400 C and O 2 flow rate at 60 mL min À1 through the chamber can result in hexagonal WO 3 with improved crystallinity and quite effective electrochemical/electrochromic response.

Our porous V2O5/TiO2 nanoheterostructure films (with a Ti/V atomic ratio of 1:1) were fabricated via a single-step sparking method using a strong magnetic field (0.5 T) without annealing requirement for the first time. We found that the magnetic flux arrangement has effect on film crystallization, unique morphology, large specific surface area, and surprisingly controllable phase structure of the films. An amorphous TV film was transformed to the TiO2 (anatase/rutile) phase (for TVN) and V2O5–VO2 mixed-phase (for TVH) without destroying the mesopores from an annealing process. Moreover, the TVH sample able to improve the degradation rate up to 270% compared with pre-annealed TV films and up to 30% with post-annealed (400 °C) TVA films. In this paper, the influence of magnetic flux arrangement on structural, morphological, optical, and photocatalytic properties of prepared sample have been investigated and reported.