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... cut-off wavelength was determined by linear extrapolation from the inflection point of the curve to the baseline. Table 1 shows the calculated band gap energy of all films. The commercial TiO 2 and the prepared TiO 2 films had similar band gap energies of 3.20 eV and 3.19 eV, respectively, while the band gap energies of the Ag/TiO 2 samples decreased from 2.86 to 2.67 eV, inversely proportional to Ag content. ...
Citations
... The modification of optical properties in TiO 2 thin films through doping is influenced by various factors including dopant type, concentration, distribution within the lattice, and fabrication conditions. A comprehensive array of research endeavors has been meticulously undertaken to delve into the intricate ramifications of doping on the photocatalytic, optical, and electrical properties of titanium dioxide (TiO 2 ), underscoring its immense potential for customizing material characteristics [6][7][8][9][10][11][12][13][14][15][16][17][18]. These studies have delved deep into the multifaceted influence of doping on TiO 2 , shedding light on its capacity to modulate various material properties to suit specific applications. ...
The present study investigates the structural and optical properties of silver (Ag)-doped titanium dioxide (TiO2) thin films prepared via flash thermal evaporation using TiO2 and Ag powders mixture at various mass ratios. The crystallinity and surface morphology of the films were studied by varying the percentage of Ag content. Structural properties were characterized using X-ray diffraction (XRD), Raman spectroscopy, and scanning electron microscopy (SEM), while optical properties were assessed through optical transmission spectra analysis. Results indicate that Ag doping enhances crystallinity, as evidenced by XRD and Raman spectroscopy, and induces surface plasmon resonance (SPR) absorption attributed to Ag nanoparticles. SEM micrographs reveal agglomerated silver particles on the film surface, confirming Ag diffusion during annealing. Surface analysis through Secondary Ion Mass Spectrometry (SIMS) measurements illustrated the diffusion of Ag within the TiO2 samples and its subsequent accumulation at the surface. We have suggested that the crystallization observed in the evaporated TiO2-Ag thin films may primarily result from the thermal diffusion of Ag metal rather than the annealing process alone. Optical transmission spectra demonstrate a shift in the absorption edge towards the visible region with increasing Ag concentration, indicating enhanced light absorption properties.
... Using the scraping instrument, the resulting material was uniformly spread onto a substrate. Finally, the film-generating plate was removed and soaked in DI water to obtain GrD TiO 2 PVC film as depicted in Figure 5C (Peerakiatkhajohn et al., 2011;Nabi et al., 2021). ...
... Meanwhile, silver nitrate was produced by mixing AgNO 3 with ethanol. The silver nitrate solution was then stirred into TiO 2 and refluxed (8 h; 80°C) (Peerakiatkhajohn et al., 2011;Lee and Li, 2021). ...
COVID-19 is one of the serious catastrophes that have a substantial influence on human health and the environment. Diverse preventive actions were implemented globally to limit its spread and transmission. Personnel protective equipment (PPE) was an important part of these control approaches. But unfortunately, these types of PPE mainly comprise plastics, which sparked challenges in the management of plastic waste. Disposable face masks (DFM) are one of the efficient strategies used across the world to ward off disease transmission. DFMs can contribute to micro and nano plastic pollution as the plastic present in the mask may degrade when exposed to certain environmental conditions. Microplastics (MPs) can enter the food chain and devastate human health. Recognizing the possible environmental risks associated with the inappropriate disposal of masks, it is crucial to avert it from becoming the next plastic crisis. To address this environmental threat, titanium dioxide (TiO 2 )-based photocatalytic degradation (PCD) of MPs is one of the promising approaches. TiO 2 -based photocatalysts exhibit excellent plastic degradation potential due to their outstanding photocatalytic ability, cost efficiency, chemical, and thermal stability. In this review, we have discussed the reports on COVID-19 waste generation, the limitation of current waste management techniques, and the environmental impact of MPs leachates from DFMs. Mainly, the prominence of TiO 2 in the PCD and the applications of TiO 2 -based photocatalysts in MPs degradation are the prime highlights of this review. Additionally, various synthesis methods to enhance the photocatalytic performance of TiO 2 and the mechanism of PCD are also discussed. Furthermore, current challenges and the future research perspective on the improvement of this approach have been proposed.
... Figure 1 shows an overview of the different stages of sol-gel process from precursor to aerogel. For the synthesis of binary or tertiary hybrid systems, a mixture of salts with different chemical compositions is used [39][40][41]. Each of the primary salts has a unique reaction rate [42][43][44][45]. ...
... Water is added when a homogeneous solution is prepared in a water-free solvent. e presence of water causes a hydrolysis reaction on the precursor and somehow activates it so that the metal oxide particles come together to form fine and solid particles dispersed in the solvent [40][41][42][43][44][45]. In a real solution, the solute is dispersed uniformly in the solvent as an atom, molecule, or ion, and the particle size does not exceed 1 nm. ...
The sol-gel process is a more chemical method (wet chemical method) for the synthesis of various nanostructures, especially metal oxide nanoparticles. In this method, the molecular precursor (usually metal alkoxide) is dissolved in water or alcohol and converted to gel by heating and stirring by hydrolysis/alcoholysis. Since the gel obtained from the hydrolysis/alcoholysis process is wet or damp, it should be dried using appropriate methods depending on the desired properties and application of the gel. For example, if it is an alcoholic solution, the drying process is done by burning alcohol. After the drying stage, the produced gels are powdered and then calcined. The sol-gel method is a cost-effective method and due to the low reaction temperature there is good control over the chemical composition of the products. The sol-gel method can be used in the process of making ceramics as a molding material and can be used as an intermediate between thin films of metal oxides in various applications. The materials obtained from the sol-gel method are used in various optical, electronic, energy, surface engineering, biosensors, and phar- maceutical and separation technologies (such as chromatography). The sol-gel method is a conventional and industrial method for the synthesis of nanoparticles with different chemical composition. The basis of the sol-gel method is the production of a homogeneous sol from the precursors and its conversion into a gel. The solvent in the gel is then removed from the gel structure and the remaining gel is dried. The properties of the dried gel depend significantly on the drying method. In other words, the “removing solvent method” is selected according to the application in which the gel will be used. Dried gels in various ways are used in industries such as surface coating, building insulation, and the production of special clothing. It is worth mentioning that, by grinding the gel by special mills, it is possible to achieve nanoparticles.
... Figure 1 shows an overview of the different stages of sol-gel process from precursor to aerogel. For the synthesis of binary or tertiary hybrid systems, a mixture of salts with different chemical compositions is used [39][40][41]. Each of the primary salts has a unique reaction rate [42][43][44][45]. ...
... Water is added when a homogeneous solution is prepared in a water-free solvent. e presence of water causes a hydrolysis reaction on the precursor and somehow activates it so that the metal oxide particles come together to form fine and solid particles dispersed in the solvent [40][41][42][43][44][45]. In a real solution, the solute is dispersed uniformly in the solvent as an atom, molecule, or ion, and the particle size does not exceed 1 nm. ...
The sol-gel process is a more chemical method (wet chemical method) for the synthesis of various nanostructures, especially metal oxide nanoparticles. In this method, the molecular precursor (usually metal alkoxide) is dissolved in water or alcohol and converted to gel by heating and stirring by hydrolysis/alcoholysis. Since the gel obtained from the hydrolysis/alcoholysis process is wet or damp, it should be dried using appropriate methods depending on the desired properties and application of the gel. For example, if it is an alcoholic solution, the drying process is done by burning alcohol. After the drying stage, the produced gels are powdered and then calcined. The sol-gel method is a cost-effective method and due to the low reaction temperature there is good control over the chemical composition of the products. The sol-gel method can be used in the process of making ceramics as a molding material and can be used as an intermediate between thin films of metal oxides in various applications. The materials obtained from the sol-gel method are used in various optical, electronic, energy, surface engineering, biosensors, and pharmaceutical and separation technologies (such as chromatography). The sol-gel method is a conventional and industrial method for the synthesis of nanoparticles with different chemical composition. The basis of the sol-gel method is the production of a homogeneous sol from the precursors and its conversion into a gel. The solvent in the gel is then removed from the gel structure and the remaining gel is dried. The properties of the dried gel depend significantly on the drying method. In other words, the “removing solvent method” is selected according to the application in which the gel will be used. Dried gels in various ways are used in industries such as surface coating, building insulation, and the production of special clothing. It is worth mentioning that, by grinding the gel by special mills, it is possible to achieve nanoparticles.
... Meanwhile, silver nitrate was synthesized by adding the AgNO 3 to ethanol. After this, prepared silver nitrate solution was added in TiO 2 , stirred, and refluxed at 80 • C for 8 h [88]. ...
The advancement in industries and modern technology has been escorted by an expansion in the utilization of chemicals to obtain plastic-based products. Increased plastic production and disposal have greatly affected the environment and living organisms globally. Macro and micro-plastics have a persistent nature, and their natural degradation takes years. Transport, impact, behavior, and degradation have attracted growing research attention. However, a review study on titanium dioxide (TiO2) based photocatalytic degradation of macro and micro-plastics has not been summarized. Herein, a brief overview of the TiO2 application for macro and micro-plastics degradation has been summarized. Different preparation methods for TiO2 synthesis and its modification for plastics decomposition have been presented. The degradation efficiency and applied system limitations with future research directions are proposed. Nevertheless, the existing knowledge about the TiO2 application for macro and micro-plastics is still limited. This work provides a good reference for plastic pollution control.
... The double peaks of Ti 2p after deconvolution corresponds to Ti 2p 1/2 at 464.4 eV and Ti 3/2 at 458.7 eV. and c optical bandgap evaluation of multiphase TiO 2 NPs from Tauc plots, where the symbols A, B and R correspond to anatase, brookite and rutile-TiO 2 [24][25][26][27][28][29][30][31][32] Apart from pure TiO 2 NPs, several groups synthesized doped TiO 2 NPs for enhancing their properties for particular application e.g., for degradation of various organic dyes such as rhodamine B, methylene blue (MB), methyl orange (MO) etc. present in waste water for water treatment [36,37]. Kerkez Peerakiatkhajohn et al. [40] prepared silver doped TiO 2 thin film on polyethylene terephthalate (PET) substrate using Titanium(IV) n-butoxide and silver nitrate (AgNO 3 ) as precursors for the preparation of thin films. The Ag/TiO 2 gel obtained from this was directly used for coating on the plastic substrate having potential applications in indoor air pollution treatment and photodegradation of gaseous pollutants such as benzene, toluene, ethylbenzene and xylene. ...
Metal oxide nanoparticles (MONPs) have enormous applications such as in optical devices, purification systems, biomedical systems, photocatalysis, photovoltaics etc. In this review, we have explored a stable and efficient synthesis protocol of particularly four MONPs: titanium dioxide (TiO2), tin oxide (SnO2), tungsten oxide (WO3) and zinc oxide (ZnO) for getting desired chemical composition, nanostructure, and surface properties. The selection of an efficient synthesis process is a key factor that significantly influences the efficacy of the MONPs. The chemical synthesis of nanoparticles (NPs) via sol–gel route is an effective method to produce high-quality MONPs in comparison to other physical and chemical methods. Sol–gel synthesis is one of the simple, fastest and economically less expensive method, and has its own advantages like low processing temperature, homogeneity of the produced material and formation of the complex structures or composite materials. We believe that this detailed review will provide an insight into sol–gel synthesis of MONPs along with their characterization and diverse applications.
... Li et al., 2011;Peerakiatkhajohn et al., 2011;Gupta et al., 2013 .) ...
... Otra aplicación interesante usando nanomateriales surge de Peerakiatkhajohn et al. (2011), quienes desarrollaron una película delgada de plata (Ag) dopada con dióxido de titanio (TiO 2 ) sensible a la luz visible sobre plástico (pet) para el tratamiento del btex, que degradó el 79% con luz visible en un tiempo de 240 minutos. Al-Sabahi et al. (2017), usaron ZnO soportado en nanobarras bajo luz visible, donde obtuvieron una degradación de más del 80% del btex en agua en un tiempo de 180 minutos. ...
In recent years there has been an interest in the treatment of water contaminated with hydrocarbons and specifically by a mixture called BTEX (benzene, toluene, ethylbenzene and xylene), which are pollutants that are commonly found in water either by discharges or spills associated with activities of the petrochemical industry. These pollutants are resistant to conventional water treatments, which increases the risk of using these contaminated water bodies for human use and consumption. The Environmental Protection Agency of the United States of America considers BTEX as priority pollutants due to its toxicity and imposes very strict maximum permissible limits, as well as those established by Mexican regulations. This article is based on a review of the common sources of BTEX in water and presents a comparison of the relevant international regulations, as well as an analysis of the treatments currently used, highlighting the application of nanotechnology for its optimization.
Key Words: BTEX, water treatment, nanotechnology
... Some of the various researches have been focused on the synthesis of visible light active TiO 2 by different methods such as doping, capping, dye sensitization and surface modification with noble metals [7][8][9]. Peerakiatkhajohn et al. [10] prepared thin films of polyethylene terephthalate (PET) containing Ag/TiO 2 by dip coating method and investigated the hydrophilicity of Ag/TiO 2 thin films. The hydrophilic PET/Ag/TiO 2 thin film has advantages on not only photocatalysis but also on self-cleaning process. ...
Abstract: Background: To produce alternative hydrophilic patterns on the surface of a nanocomposite,
many different approaches have been used. The ionic liquid (IL) microemulsions expanding the
potential uses of ILs that can provide hydrophilic or hydrophobic nanodomains as a nanoreactor to the
synthesis of a novel type of nanocomposites with special properties
Objective: This study aims to investigate photo-induced hydrophilicity of modified poly(methyl methacrylate)
(PMMA) containing TiO2 nanoparticles, synthesized by using ionic liquid-in-oil microemulsion
system.
Materials and Methods: A series of visible light-responsive PMMA/TiO2 nanocomposite films were
prepared in an ionic liquid (IL) based microemulsion containing methyl methacrylate monomer, 1-
buthyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]), Triton X-100 and 1-buthanol. The ternary
phase diagram of the microemulsion system has been constructed and concluded that it is thermodynamically
stable at polymerization temperature of 60°C. The oil phase of the system was polymerized
to obtain the PMMA nanocomposite films with different concentration of TiO2 nanoparticles.
Techniques such as XRD, AFM and TEM were carried out to characterize the fabricated transparent
nanocomposite films. The visible light photo-induced hydrophilicity of the prepared
PMMA/IL/TiO2 films was evaluated by measuring the contact angle of water on a thin film of the
nanocomposite during the visible light illumination.
Results: The results showed that the surface hydrophilicity of the nanocomposites will be changed
significantly with light illumination and the PMMA/IL with 0.01 wt.% loading of TiO2 showed the
best hydrophilicity. The contact angle of the nanocomposite was decreased with increasing of irradiation
time and from that, the surface energy and work of adhesion increased.
Conclusion: It is concluded that modification of TiO2 nanoparticles with ionic liquid is a new approach
for making visible light photo-induced polymer nanocomposites with improved hydrophilicity
performance.
... From the manufacturing point of view, it is also interesting that the technique allows the use of flexible substrates like carbon fibre and polymer foils, among others. The deposition onto flexible supports facilitates the transport and manipulation in shape-adaptable devices [12,13] and enables a low-cost mass production by roll-to-roll based continuous fabrication processes [14,15]. In addition, it allows the preparation of tailor-made photocatalytic coatings with improved reactivity due to the control of the nanostructure from amorphous to even preferentially facet-oriented [16,17]. ...
... This evidences the fast variation occurring with low TiO 2 charges, and then a slower evolution with the thicker coatings. Then, the highest absorption coefficients correspond to the amorphous coating, in the same way as observed for other sputtered TiO 2 layers [12,29]. ...
Advancing in the photocatalyst scale-up is crucial for the development of highly efficient solar fuels production at industrial scale. Here, we report DC-magnetron sputtering as a suitable technique to produce photocatalytic TiO2 coatings for CO2 reduction with a view on process scalability. The crystallinity of the obtained TiO2 coatings varies with surface density, with amorphous or quasi-amorphous coatings obtained with very low densities, while UV light absorption coefficients show the opposite trend, which has been related to the proportionally higher abundace of surface defects and grain boundaries associated to the small crystal size and/or amorphicity of the lightest coatings. The as-prepared samples lead to the reduction of CO2 as demonstrated by ¹³C isotope tracing. An optimum catalyst area density of 1 g/m² (by geometric area) is obtained in terms of CO2 photoreduction production, which is ascribed to a compromise situation between crystallinity and absorption coefficient. Selectivity to the different reaction products also varies with the coating characteristics, with amorphous or quasi-amorphous light coatings favouring methanol formation, in contrast with the preferred CO evolution in heavier, crystalline ones. Raman spectroscopy reveals the formation of peroxo and peroxocarbonate species on the photocatalyst surface as oxidation products during the CO2 reduction, the accummulation of which is proposed to be related to the observed catalyst deactivation.
