scholarly journals Adsorption and Photocatalytic Reduction of Carbon Dioxide on TiO2

Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 47
Author(s):  
Oleksandr Shtyka ◽  
Viktar Shatsila ◽  
Radoslaw Ciesielski ◽  
Adam Kedziora ◽  
Waldemar Maniukiewicz ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Active Sites ◽  
High Efficiency ◽  
Chemical Potential ◽  
Band Gap Energy ◽  
Electromagnetic Spectrum ◽  
Reaction Intermediates ◽  
Factors Affecting ◽  
Phase Reduction ◽  
Reduction Of Co2

The photocatalytic activity of TiO2 depends on numerous factors, such as the chemical potential of electrons, charge transport properties, band-gap energy, and concentration of surface-active sites. A lot of research has been dedicated to determining the properties that have the most significant influence on the photocatalytic activity of semiconductors. Here, we demonstrated that the activity of TiO2 in the gas-phase reduction of CO2 is governed mainly by the desorption rate of the reaction intermediates and final products. This indicates that the specific surface area of TiO2 and binding strength of reaction intermediates and products are the main factors affecting the photocatalytic activity of TiO2 in the investigated process. Additionally, it was shown that rutile exhibits higher photocatalytic activity than anatase/rutile mixtures mainly due to its high efficiency in the visible portion of the electromagnetic spectrum.

scholarly journals Comparative study on photocatalytic activity of transition metals (Ag and Ni)-doped ZnO nanomaterials synthesized via sol–gel method

2020 ◽  
Vol 7 (2) ◽  
pp. 191590 ◽  
Author(s):  
A. K. Azfar ◽  
M. F. Kasim ◽  
I. M. Lokman ◽  
H. A. Rafaie ◽  
M. S. Mastuli
Keyword(s):  
Photocatalytic Activity ◽  
Active Sites ◽  
Sol Gel ◽  
Textural Properties ◽  
High Photocatalytic Activity ◽  
Factors Affecting ◽  
Gel Method ◽  
Sol Gel Method ◽  
Zno Nanomaterials ◽  
Almost All

Ag and Ni/ZnO photocatalyst nanostructures were successfully synthesized by a sol–gel method. In this work, the photocatalyst sample was systematically studied based on several factors affecting the performance of photocatalyst, which are size, morphology, band gap, textural properties and the number of active sites presence on the surface of the nanocatalyst. X-ray diffraction revealed that Ag/ZnO nanomaterials experienced multiple phases, meanwhile for Ni/ZnO the phase of nanomaterials were pure and single phase for stoichiometry less than 5%. Field emission scanning electron microscope (FESEM) showed almost all of the synthesized nanomaterials possessed a mixture of nanorods and spherical-like shape morphology. The Ag/ZnO showed high photocatalytic activity, producing at least 14th trials of nanocatalyst reusability on degradation of methyl orange under UV irradiation. Interestingly, this phenomenon was not observed in larger surface area of Ni/ZnO nanomaterials which supposedly favour photocatalytic activity, but instead producing poor photocatalytic performance. The main reasons were studied and exposed by temperature-programmed desorption of carbon dioxide (TPD–CO 2 ) which showed that incorporation of Ag into ZnO lattice has enhanced the number of active sites on the surface of the nanocatalyst. Whereas incorporation of Ni in ZnO has lowered the number of active sites with respect to undoped ZnO. Active sites measurement is effective and significant, providing opportunities in developing an intensive study as an additional factor.

scholarly journals Highly photocatalytic activity of natural halloysite - based material for the treatment of dyes in wastewater

2021 ◽  
Vol 62 (3) ◽  
pp. 19-28
Author(s):  
Keyword(s):  
Photocatalytic Activity ◽  
High Efficiency ◽  
Organic Pollutant ◽  
Band Gap Energy ◽  
Pure Tio2 ◽  
Environmental Treatment ◽  
Bet Method ◽  
Novel Material ◽  
Physicochemical Methods ◽  
Capillary Size

In this study, the halloysite nanotube material will be fabricated from a natural halloysite mineral and used as a support for the photocatalytic activity phase based on TiO2. The material is characterized by modern physicochemical methods such as XRD, SEM, BET, UV - vis spectrum, and EDX. Accordingly, the refined halloysite has a nanoscale with a length of about 1.3 μm and a capillary size of about 5 nm. After the deposition of Ag - TiO2 on the halloysite, the specific surface of the material measured by the BET method was about 60 m2/g, and the structure of the halloysite was intact. The band - gap energy of as - prepared materials is also significantly improved in comparison to pure TiO2, makes the material capable of absorbing longer wavelengths of light in the photocatalytic process. The Photocatalyst based on Halloysite and TiO2 showed very high efficiency, up to more than 95% in the decomposition of typical organic pollutant RR - 195. This result shows great potential in this novel material in environmental treatment applications.

Research on springback characteristic in flexible multi-points 3D stretch-bending process

2021 ◽  
pp. 095440542110284
Author(s):  
Song Gao ◽  
Tonggui He ◽  
Qihan Li ◽  
Yingli Sun ◽  
Jicai Liang
Keyword(s):  
Simulation Model ◽  
High Efficiency ◽  
Vertical Direction ◽  
Factors Affecting ◽  
Stretch Bending ◽  
Element Simulation ◽  
Bending Process ◽  
Bending Radius ◽  
Aluminum Profiles ◽  
Bending Sequence

The problem of springback is one of the most significant factors affecting the forming accuracy for aluminum 3D stretch-bending parts. In order to achieve high-efficiency and high-quality forming of such kind of structural components, the springback behaviors of the AA6082 aluminum profiles are investigated based on the flexible multi-points 3D stretch-bending process (3D FSB). Firstly, a finite element simulation model for the 3D FSB process was developed to analyze the forming procedure and the springback procedure. The forming experiments were carried out for the rectangle-section profile to verify the effectiveness of the simulation model. Secondly, the influence of tension on springback was studied, which include the pre-stretching and the post-stretching. Furthermore, the influences of the bending radius and bending sequence are revealed. The results show that: (1) The numerical model can be used to evaluate the effects of bending radius and process parameters on springback in the 3D FSB process effectively. (2) The pre-stretching has little effect on the horizontal springback reduction, but it plays a prominent role in reducing the springback in the vertical direction. (3) The increase of bending deformation in any direction will lead to an increase of springback in its direction and reduce the springback in the other direction. Besides, it reduces the relative error in both directions simultaneously. This research established a foundation to achieve the precise forming of the 3D stretch-bending parts with closed symmetrical cross-section.

scholarly journals Measuring the Efficiency of Football Clubs Using Data Envelopment Analysis: Empirical Evidence From Spanish Professional Football

SAGE Open ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 215824402198925
Author(s):  
Isidoro Guzmán-Raja ◽  
Manuela Guzmán-Raja
Keyword(s):  
Data Envelopment Analysis ◽  
High Efficiency ◽  
Sport Performance ◽  
Data Envelopment ◽  
Professional Football ◽  
Efficiency Measure ◽  
Factors Affecting ◽  
Football Clubs ◽  
Main Factors ◽  
Using Data

Professional football clubs have a special characteristic not shared by other types of companies: their sport performance (on the field) is important, in addition to their financial performance (off the field). The aim of this paper is to calculate an efficiency measure using a model that combines performance (sport and economic) based on data envelopment analysis (DEA). The main factors affecting teams’ efficiency levels are investigated using cluster analysis. For a sample of Spanish football clubs, the findings indicate that clubs achieved a relatively high efficiency level for the period studied, and that the oldest teams with the most assets had the highest efficiency scores. These results could help club managers to improve the performance of their teams.

scholarly journals Analysis of factors affecting IoT-based smart hospital design

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Banu Çalış Uslu ◽  
Ertuğ Okay ◽  
Erkan Dursun
Keyword(s):  
High Efficiency ◽  
Health Sector ◽  
Transformation Process ◽  
Healthcare Management ◽  
Hospital System ◽  
Intelligent Computing ◽  
Factors Affecting ◽  
Hospital Design ◽  
Road Map ◽  
Smart Hospital

AbstractCurrently, rapidly developing digital technological innovations affect and change the integrated information management processes of all sectors. The high efficiency of these innovations has inevitably pushed the health sector into a digital transformation process to optimize the technologies and methodologies used to optimize healthcare management systems. In this transformation, the Internet of Things (IoT) technology plays an important role, which enables many devices to connect and work together. IoT allows systems to work together using sensors, connection methods, internet protocols, databases, cloud computing, and analytic as infrastructure. In this respect, it is necessary to establish the necessary technical infrastructure and a suitable environment for the development of smart hospitals. This study points out the optimization factors, challenges, available technologies, and opportunities, as well as the system architecture that come about by employing IoT technology in smart hospital environments. In order to do that, the required technical infrastructure is divided into five layers and the system infrastructure, constraints, and methods needed in each layer are specified, which also includes the smart hospital’s dimensions and extent of intelligent computing and real-time big data analytic. As a result of the study, the deficiencies that may arise in each layer for the smart hospital design model and the factors that should be taken into account to eliminate them are explained. It is expected to provide a road map to managers, system developers, and researchers interested in optimization of the design of the smart hospital system.

scholarly journals Synthesis and Characterization of Ag@C-TiO2 Nanocomposite for Degradation of Sasirangan Textile Wastewater

2019 ◽  
Vol 22 (6) ◽  
pp. 299-304
Author(s):  
Heny Puspita Dewi ◽  
Joko Santoso ◽  
Nur Firda Trianda ◽  
Rodiansono Rodiansono
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Textile Wastewater ◽  
Band Gap Energy ◽  
Tio2 Photocatalyst ◽  
Composite Photocatalysts ◽  
Xrd Patterns ◽  
Brookite Phase

Carbon-titanium oxide nanocomposite (denoted as @C-TiO2) was successfully synthesized via hydrothermal method at 150°C for 24 h. The C-TiO2 nanocomposite was furtherly modified by adding an Ag metal dopant (denoted as Ag@C-TiO2) to improve and applied to the photocatalytic degradation of Sasirangan textile wastewater. The composite photocatalysts were characterized by XRD and UV–Vis DRS spectroscopies. XRD patterns showed that TiO2 in @C-TiO2 mainly consisted of a brookite phase, as indicated by a series sharp diffraction peak at 2θ = 27.2° (111), 31.5° (121) and 55.9° (241). The calculated band gap energy (Eg) derived from UV-Vis DRS spectra for TiO2, @C-TiO2, and Ag@C-TiO2 were 2.95 eV, 2.54 eV, and 2.74 eV, respectively. Ag@C-TiO2 photocatalyst was found to be active for the photocatalytic degradation of Sasirangan textile wastewater, as indicated by the change of wastewater color from dark to clear. The quantitative photocatalytic activity of Ag@C-TiO2 was evaluated in the degradation of methylene blue, whereas the conversion of methylene blue was 41.3%. The addition of Ag to @C-TiO2 is believed to play an essential role in the enhancement of photocatalytic activity.

scholarly journals Heterogeneous Catalytic Synthesis of 2-Methylbenzimidazole from 2-Nitroaniline and Ethanol Over Mg Modified Cu-Pd/γ-Al2O3

Catalysts ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 8 ◽  
Author(s):  
Feng Feng ◽  
Yaqin Deng ◽  
Zheng Cheng ◽  
Xiaoliang Xu ◽  
Qunfeng Zhang ◽  
...  
Keyword(s):  
Active Sites ◽  
Hydrogen Transfer ◽  
High Efficiency ◽  
Simple Procedure ◽  
Direct Synthesis ◽  
Reaction System ◽  
Simple Method ◽  
Heterogeneous Catalytic ◽  
Coupled Reaction ◽  
Al2o3 Catalyst

The direct synthesis of benzimidazoles from 2-nitroaniline and ethanol over Cu-Pd/γ-Al2O3 catalysts has the advantages of requiring easily available starting materials, having high efficiency, and a simple procedure. The modification by Mg of the Cu-Pd/γ-Al2O3 catalyst could improve the catalytic activity significantly. The addition of Mg to the Cu-Pd/γ-Al2O3 catalyst could maintain and promote the formation of CuPd alloy active sites. Meanwhile, the basicity of the support was enhanced appropriately by Mg, which generated more basic sites (Al-Oδ−) to accelerate the dehydrogenation of alcohol and increased the rate of the whole coupled reaction. The 2-nitroaniline was completely converted over Cu-Pd/(Mg)γ-Al2O3 after reacting for six hours, and the yield of 2-methylbenzimidazole was 98.8%. The results of this work provide a simple method to develop a more efficient catalyst for the “alcohol-dehydrogenation, hydrogen transfer and hydrogenation” coupled reaction system.

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