The Effects of the Content of NiO on the Microstructure and Photocatalytic Activity of the NiO/TiO2 Composite Film

The NiO/TiO2 composite films with the NiO content of 3 %, 5 %, 10 %, 13 %, 15 % and 20 % were prepared by mechanical coating technology and subsequent oxidation process. The composition and microstructure of the films were analyzed by X-ray Diffraction (XRD), scanning electron microscope (SEM), and energy dispersive spectroscopy (EDS). The photocatalytic activity was evaluated and the effects of the content of NiO on microstructure and photocatalytic activity of the films were studied. The results show that NiO particles are dispersed in the Ti coatings, and the NiO concentration in the inner layer of the coatings is higher than in the outer layer. With the addition of NiO in the NiO/Ti coating, the ductility is deteriorated and the thickness is reduced of the NiO/Ti coatings. The films with NiO/TiO2/Ti composite microstructure are obtained by the oxidation of NiO/Ti coatings. Photocatalytic efficiency of the films is obviously enhanced with the help of the p-n junction heterostructure in the NiO/TiO2 films. The optimum content of NiO is about 13 %, and the degradation rate of methyl orange solution reaches the maximum value of 88.44 %. DOI: http://dx.doi.org/10.5755/j01.ms.24.4.19266</p

Preparation of Copper Oxide/TiO2 Composite Films by Mechanical Ball Milling and Investigated Photocatalytic Activity

The Cu/Ti composite coatings were prepared by the mechanical ball milling, the CuO/TiO2 and Cu2O/TiO2 composite photocatalytic films were obtained by the subsequent oxidation process. The microstructure of the composite films was analyzed by X-ray Diffraction (XRD）and scanning election microscope (SEM). The photocatalytic activity was evaluated, the effects of ball milling time on the formation of the Cu/Ti coatings were investigated, and the effects of the oxidation temperature and oxidation atmosphere on microstructure and photocatalytic activity of the films were studied. The results illustrate that the ball milling time has significant effects on the formation of the coatings and the coatings are continuous and compact by ball milling for 15 h. The photocatalytic activity of the CuO/TiO2 composite films is increased first and then decreased with the oxidation temperature increases, and the photocatalytic activity is the best at 500 °C. The CuO/TiO2 composite films are obtained by the oxidation of Cu/Ti coatings at 500 °C for 15 h in the air, while the Cu2O/TiO2 composite films are oxidized in carbon atmosphere. Photocatalysis efficiency of the films is obviously enhanced with the help of the p-n junction heterostructure in the Cu2O/TiO2 composite films

Effects of oxidation temperature on the microstructure and photocatalytic activity of the TiO2 coating

Titanium coatings have been prepared on the surface of 1mm ZrO2 balls by mechanical ball mill, then the coatings are oxidized to photocatalyst TiO2 films at 400~600°C. XRD, SEM, EDS and OM were used to analyze the microstructure of the films. The photocatalytic activity of the samples is also evaluated. After that the effects of oxidation temperature on the microstructure and photocatalytic activity of the films has been discussed. Result shows that, oxygen elements are imported into the inner coatings by the gaps existed in the Ti coatings, which makes the Ti particles oxidized from surface to core, finally the films with TiO2+Ti composite microstructure are obtained. The films have the best photocatalytic performance with degradation rate of methyl orange solution 79.08% by oxidation at 500°C, this owing to the existence of anatase and the composite microstructure

Effects of oxidation temperature on the microstructure and photocatalytic activity of the TiO₂ coating

224-227Titanium coatings have been prepared on the surface of 1mm ZrO2 balls by mechanical ball mill, then the coatings are oxidized to photocatalyst TiO2 films at 400~600&deg;C. XRD, SEM, EDS and OM were used to analyze the microstructure of the films. The photocatalytic activity of the samples is also evaluated. After that the effects of oxidation temperature on the microstructure and photocatalytic activity of the films has been discussed. Result shows that, oxygen elements are imported into the inner coatings by the gaps existed in the Ti coatings, which makes the Ti particles oxidized from surface to core, finally the films with TiO2+Ti composite microstructure are obtained. The films have the best photocatalytic performance with degradation rate of methyl orange solution 79.08% by oxidation at 500&deg;C, this owing to the existence of anatase and the composite microstructure

The Effects of Oxidation Temperature on the Microstructure and Photocatalytic Activity of the TiO2 Coating

Titanium coatings were prepared on the surface of 1mm ZrO2 balls by mechanical ball mill, then the coatings were oxidized to photocatalytic TiO2 films at 400 ~ 600 °C. X-Ray Diffraction, Scanning Electron Microscope, Energy Dispersive Spectroscopy and Optical Microscope were used to analyze the microstructure and crystal form of the films. The photocatalytic activity of the samples was also evaluated. After that, the effects of oxidation temperature on the microstructure and photocatalytic activity of the films were discussed. The results show that the fabricated coatings are uneven, with average thickness of 60 μm. In the process of oxidation, oxygen is imported into the inner coatings by the gaps existed in the Ti coatings, which makes the Ti particles oxidize from surface to core, finally the films with TiO2 + Ti composite microstructure are obtained. The films oxidized at 500 °C have the best photocatalytic performance with the degradation rate of methyl orange solution 79.08 %, this owing to the existence of anatase and the TiO2+Ti composite microstructure. The result will provide theoretical basis for the fabrication of efficient photocatalytic film

Angiography-based hemodynamic features predict recurrent ischemic events after angioplasty and stenting of intracranial vertebrobasilar atherosclerotic stenosis.

Acknowledgements: The authors gratefully acknowledge the participants of the study and clinical staff of Jinling Hospital who contributed to patient recruitment and data collection.OBJECTIVES: To assess the predictive value of hemodynamic features for stroke relapse in patients with intracranial vertebrobasilar atherosclerotic stenosis treated with percutaneous transluminal angioplasty and stenting (PTAS) using quantitative digital subtraction angiography (q-DSA). METHODS: In this retrospective longitudinal study, patients with intracranial vertebrobasilar atherosclerotic stenosis and who underwent PTAS treatment between January 2012 and May 2020 were enrolled. The q-DSA assessment was performed before and after PTAS. ROIs 1-4 were placed along the vertebral artery, proximal and distal basilar artery, and posterior cerebral artery; ROIs 5-8 were in 5 mm and 10 mm proximal and distal to the lesion, respectively. Relative time to peak (rTTP) was defined as the difference in TTP between ROIs. Cox regression analyses were performed to determine risk factors for recurrent stroke. RESULTS: A total of 137 patients (mean age, 62 years ± 10 [standard deviation], 83.2% males) were included, and 26 (19.0%) patients had stroke relapse during follow-up (median time of 42.6 months [interquartile range, 19.7-60.7]). Preprocedural rTTP4-1 (adjusted hazard ratio (HR) = 2.270; 95% CI 1.371-3.758; p = 0.001) and preprocedural rTTP8-5 (adjusted HR = 0.240; 95% CI 0.088-0.658; p = 0.006) were independently associated with the recurrent stroke. These hemodynamic parameters provided an incremental prognostic value for stroke relapse (AUC, 0.817 [0.704-0.931]; the net reclassification index, 0.431 [0.057-0.625]; and the integrated discrimination index, 0.140 [0.035-0.292]). CONCLUSIONS: In patients with intracranial vertebrobasilar atherosclerosis treated with PTAS, preprocedural prolonged TTP of the target vessel and shortened trans-stenotic TTP difference were associated with stroke relapse. Q-DSA-defined hemodynamic parameters provided incremental predictive value over conventional parameters for stroke recurrence. CLINICAL RELEVANCE STATEMENT: Quantitative DSA analysis enables intuitive observation and semi-quantitative evaluation of peri-therapeutic cerebral blood flow. More importantly, quantitative DSA-defined hemodynamic parameters have the potential for risk stratification of patients with intracranial atherosclerotic stenosis. KEY POINTS: Semi-quantitative angiography-based parameters can reflect pre- and postprocedural subtle changes in blood flow in patients with intracranial atherosclerotic stenosis. Although angioplasty procedures can significantly improve blood flow status, patients with more restricted baseline blood flow still show a higher risk of stroke recurrence. Angiography-based hemodynamic features possess prognostic value and can serve as clinical markers to assess stroke risk of patients with intracranial atherosclerotic stenosis