Victor Jaya Nesamony; Namagal Selvan
Abstract
The nanostructured material properties are different from the bulk materials. Nanofibers are widely studied for many applications like tissue engineering, wound dressings, electronics, storage, catalysts, protective clothing, sensors, and cosmetics. In this study, pure form of one-dimensional TiO2 nanofibers ...
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The nanostructured material properties are different from the bulk materials. Nanofibers are widely studied for many applications like tissue engineering, wound dressings, electronics, storage, catalysts, protective clothing, sensors, and cosmetics. In this study, pure form of one-dimensional TiO2 nanofibers have been successfully obtained by electrospinning technique and TiO2 nanopowders are synthesized by a conventional Sol-Gel method followed by high-temperature calcinations. The as-obtained products are characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy-Dispersive X-Ray (EDX) spectroscopy. The XRD results reveal the crystallite size of the synthesized material. SEM images depict the formation of nanopowders and nanofibers. EDX studies confirmed the presence of Ti and O in the prepared samples.
Yulong Ma; Kaimo Deng; Bangkai Gu; Hao Lu; Yayun Zhu; Liang Li
Abstract
The electron transport material has the great effect on the performance of hybrid perovskite solar cells. TiO2 is widely chosen as the electron transport layer due to its facile synthesis and excellent charge extraction capability. Here, for the first time, we utilize the hydrogen treated TiO2 as the ...
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The electron transport material has the great effect on the performance of hybrid perovskite solar cells. TiO2 is widely chosen as the electron transport layer due to its facile synthesis and excellent charge extraction capability. Here, for the first time, we utilize the hydrogen treated TiO2 as the electron transport layer for improving the performance of perovskite solar cells. The hydrogen treatment increases the Fermi level and conductivity of TiO2, and the device based on hydrogen treated TiO2 exhibits a power conversion efficiency of 13.15% compared with 9.45% for the reference device with untreated TiO2. The results highlight the importance of optimizing the electron transport material and provide a new route to fabricate highly efficient planar perovskite solar cells.
Sandip Maiti; Ranadip Bera;Bhanu B. Khatua; Sumanta K. Karan; Amit K. Das
Abstract
Renewable energy is very much demanding in modern time. Herein, we have discussed energy storage performance of polyaniline (PANI) and carbon nanohorn (CNH) decorated titanium dioxide (TiO2) nanoparticle, high-performance electrode material. This high-performance energy storage material was prepared ...
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Renewable energy is very much demanding in modern time. Herein, we have discussed energy storage performance of polyaniline (PANI) and carbon nanohorn (CNH) decorated titanium dioxide (TiO2) nanoparticle, high-performance electrode material. This high-performance energy storage material was prepared through simple and cost-effective method via in-situ polymerization of aniline in presence of CNH and TiO2 nanoparticles. Thus, as prepared active electrode material provides high specific capacitance value of 1068 F/g at current density of 3 A/g. The existence TiO2 nanoparticle in the ternary hybrid leads to enhancement of capacitance value through synergistic effect compared to the pure components (e.g., PANI and CNH are 335 F/g and 240 F/g, respectively at same current density). As morphological analysis says, TiO2 nanoparticles are observed to be coated by CNH nanofiller and PANI fiber in the hybrid, which plays a key role to enhance the capacitance value of hybrid making it highly promising electrode material for energy storage in the next-generation power supply.
Srikanta Karmakar; Subrata Biswas; Pathik Kumbhakar; Tapan Ganguly
Abstract
In this work, we have reported an eco-friendly and cost-effective technique of synthesis of TiO2@Carbon nanocomposites (TCNs) material by a facile solvothermal treatment of banana (Musa balbisiana) bract extract. Yellow-green photoluminescence (PL) feature and efficient catalytic activities of green ...
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In this work, we have reported an eco-friendly and cost-effective technique of synthesis of TiO2@Carbon nanocomposites (TCNs) material by a facile solvothermal treatment of banana (Musa balbisiana) bract extract. Yellow-green photoluminescence (PL) feature and efficient catalytic activities of green synthesized TCNs have been demonstrated. X-ray diffraction (XRD) data has revealed the simultaneous presence of rutile and anatase phases of TiO2 in the synthesized TCNs. The presence of amorphous carbon and TiO2 is also confirmed by Raman spectroscopy. The light emission characteristics of TCNs are studied by PL emission spectroscopy which has confirmed the presence of defect levels caused by oxygen vacancies and surface hydroxyl groups localized within the band-gap. The photocatalytic performance of the synthesized material has been systematically evaluated by observing the degradation of Methylene Blue (MB) dye under the incidence of ultraviolet-visible (UV-Vis)/visible light irradiation and manifested a superior UV-Vis light photo-catalytic activity far over the commercial TiO2 powder (CTP) under the same experimental conditions. A relatively higher electrochemical performance and 52 times larger cathodic current density is obtained in TCNs in compared to that of CTP. TCNs exhibit extremely high hydrogen evolution reaction catalytic activity with very small onset over potential.
A. Dussan; Heiddy P. Quiroz
Abstract
In this work, we fabricated samples of titanium dioxide nanotube arrays via electrochemical anodization by using titanium foils as anode and cathode. A solution of water, ethyleneglycol, and ammonium fluoride (NH4F) at room temperature was used for the samples synthesis process. Different times and anodizing ...
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In this work, we fabricated samples of titanium dioxide nanotube arrays via electrochemical anodization by using titanium foils as anode and cathode. A solution of water, ethyleneglycol, and ammonium fluoride (NH4F) at room temperature was used for the samples synthesis process. Different times and anodizing voltages were used during reaction. From X-ray diffraction (XRD) and micro-diffraction (mXRD) measurements, rutile and anatase phases were identified as function of deposition parameters. The Ti3O5 phase was observed by deconvolution of Debye-Scherrer rings of the microdiffraction spectra. Annealing processes were performed for all samples in the range between 273 and 723 K, without changes in the material’s morphological properties, while the crystalline structure was affected. Nanotube diameters varying between 30 and 42 nm were observed from SEM micrographs, when NH4F concentration was changed from 0.25 to 0.50 wt%. An alternating anodizing voltage generates the formation of nanotubes evenly spaced on the surface with nodes in bamboo-type form, while a smooth form for nanotubes was observed with constant applied voltage. From stereoscopic 3D micrographs, a reconstruction of the topographic surface of the TiO2 nanotubes was conducted. A correlation between synthesis parameters and morphological properties is presented.
Jaspal Singh; Kavita Sahu; Sini Kuriakose; Nishant Tripathi; D. K. Avasthi; Satyabrata Mohapatra
Abstract
Nanostructured TiO2 thin films with highly enhanced photocatalytic activity were prepared by atom beam sputtering technique. The effects of thermal annealing on the structural, morphological and photocatalytic properties of TiO2 thin films were investigated using X-ray diffraction, atomic force microscopy, ...
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Nanostructured TiO2 thin films with highly enhanced photocatalytic activity were prepared by atom beam sputtering technique. The effects of thermal annealing on the structural, morphological and photocatalytic properties of TiO2 thin films were investigated using X-ray diffraction, atomic force microscopy, field emission scanning electron microscopy, Raman spectroscopy and UV-visible absorption spectroscopy. X-ray diffraction studies showed that the as-deposited TiO2 thin films made up of anatase TiO2 nanoparticles transformed into anatase/ rutile mixed-phase TiO2 nanoparticles upon annealing. Field emission scanning electron microscopy and atomic force microscopy studies revealed growth of TiO2 nanoparticles from 16 nm to 29 nm upon annealing at 600 o C. The photocatalytic activities of the nanostructured TiO2 thin films were studied by monitoring photocatalytic degradation of methylene blue in water. Our results showed that the as-deposited nanostructured TiO2 thin films exhibited highly enhanced photocatalytic efficiency as compared to the annealed samples. The mechanism underlying the enhanced photocatalytic activity of nanostructured TiO2 thin film is tentatively proposed.
Hyun-Je Sung; Sang-Chul Jung;Jung-Sik Kim; Byung-Min Ki
Abstract
The photocatalytic behaviors of TiO2-supported on the long lasting phosphor beads were examined. Nanocrystalline TiO2 was coated on ellipsoidal-spherical beads of an alkaline earth aluminate phosphor, Sr4Al14O25:Eu 2+ , Dy 3+ , by low pressure chemical vapor deposition (LPCVD). The photocatalytic reaction ...
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The photocatalytic behaviors of TiO2-supported on the long lasting phosphor beads were examined. Nanocrystalline TiO2 was coated on ellipsoidal-spherical beads of an alkaline earth aluminate phosphor, Sr4Al14O25:Eu 2+ , Dy 3+ , by low pressure chemical vapor deposition (LPCVD). The photocatalytic reaction was examined by measuring the decomposition of benzene and toluene gases by gas chromatography under ultraviolet, visible light (λ> 410 nm) irradiation, as well as in the dark. The LPCVD TiO2-coated Sr4Al14O25:Eu 2+ , Dy 3+ showed an active photocatalytic reaction under visible irradiation. The mechanisms of the photocatalytic reactivity for the TiO2-coated Sr4Al14O25:Eu 2+ , Dy 3+ phosphor beads were discussed in terms of the crystal structure at the interface, energy band structure and phosphorescence. The coupling of TiO2 with the Sr4Al14O25:Eu 2+ , Dy 3+ phosphor resulted in energy band bending in the junction region between TiO2 and Sr4Al14O25:Eu 2+ , Dy 3+ phosphor, which makes the TiO2 crystal at the interface photo-reactive under visible light irradiation. The LPCVD TiO2-coated Sr4Al14O25:Eu 2+ , Dy 3+ phosphor beads were also photo-reactive in the dark through the light photons emitted from the Sr4Al14O25:Eu 2+ , Dy 3+ phosphor.
Jaspal Singh; Satyabrata Mohapatra
Abstract
Nanostructures of TiO2 were synthesized by a facile sol-gel method using pentanol as solvent. The effects of thermal annealing on the structural, optical and photocatalytic properties of as-synthesized TiO2 nanostructures have been studied using X-ray diffraction (XRD), atomic force microscopy (AFM), ...
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Nanostructures of TiO2 were synthesized by a facile sol-gel method using pentanol as solvent. The effects of thermal annealing on the structural, optical and photocatalytic properties of as-synthesized TiO2 nanostructures have been studied using X-ray diffraction (XRD), atomic force microscopy (AFM), Raman spectroscopy and UV-visible absorption spectroscopy. XRD and Raman spectroscopy results revealed that the synthesized TiO2 nanostructures exist in anatase phase for annealing at temperatures up to 300 o C, while annealing at 600 o C led to the formation of TiO2 nanostructures in anatase/rutile mixed-phase. AFM studies revealed the presence of TiO2 nanorods, which showed a small decrease in aspect ratio upon annealing. The photocatalytic activity of nanostructured TiO2 samples was evaluated through sun light driven degradation of methylene blue (MB) dye in water. TiO2 nanorods in anatase/rutile mixed-phase in the sample annealed at 600 o C were found to exhibit the highest photocatalytic activity towards degradation of MB dye. The mechanism underlying the enhanced photocatalytic activity of TiO2 nanostructures in anatase/rutile mixed-phase is tentatively proposed.
P. Muthirulan; C. K. N. Devi; M. M. Sundaram
Abstract
Simple and proficient methodology has been proposed for the preparation of hybrid photocatalyst based on titanium dioxide (TiO2)-graphene (GR) nanocomposite for acid orange 7 (AO7) dye degradation under UV irradiation. High Resolution Transmission Electron Microscopy (HRTEM) and Scanning Electron Microscopy ...
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Simple and proficient methodology has been proposed for the preparation of hybrid photocatalyst based on titanium dioxide (TiO2)-graphene (GR) nanocomposite for acid orange 7 (AO7) dye degradation under UV irradiation. High Resolution Transmission Electron Microscopy (HRTEM) and Scanning Electron Microscopy (SEM) studies revealed that TiO2 nanoparticles were uniformly dispersed on GR surface. TiO2-GR hybrid nanocomposite has also been characterized by Ultraviolet Diffusive Reflectance Spectroscopy (UV-DRS), Raman spectroscopy and X-ray diffraction (XRD) studies. Electrochemical Impedance spectroscopy (EIS) measurement revealed that the incorporation of GR with TiO2 nanoparticles significantly enhanced the electrical conductivity.The peak intensity of PL spectra of GR containing catalysts are lower than that of pristine TiO2, indicating that the electron–hole recombination rate of self-trapped excitations in TiO2 is reduced by the introduction of GR. The photocatalytic degradation measurements demonstrated that the TiO2-GR composites exhibited an enhanced photocatalytic activity for AO7 degradationunder UV irradiation compared to pure TiO2. This may due to greater adsorptivity ofdyes, extended light absorption and increased charge separation efficiency due to excellent electricalproperties of graphene and the large surface contact between graphene and TiO2 nanoparticles. Therefore, the TiO2-GR composites can be widely used as a ternary composite photocatalyst for treating the organic contaminant in the field of environmental protection.
Deman Han; Yongmin Li; Wenping Jia
Abstract
A novel 2, 4-dichlorophenol imprinted TiO2-SiO2 catalyst was prepared by molecular imprinting technique in combination with sol-gel method. The prepared material was characterized by X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron-microscopy (SEM), transmission electron microscopy ...
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A novel 2, 4-dichlorophenol imprinted TiO2-SiO2 catalyst was prepared by molecular imprinting technique in combination with sol-gel method. The prepared material was characterized by X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron-microscopy (SEM), transmission electron microscopy (TEM) and N2 adsorption measurement. The effect of the preparation condition on the degradation behavior, the photo-catalytic ability and selectivity of the prepared material were evaluated. The results show that the imprinted material has good photo-degradation capacity and selectivity toward the target pollutant, which was shown to be promising for selective removal of 2, 4-dichlorophenol from environmental samples.
Li Chen; Guangshui Yua;Jianming Zhanga; Xiujiang Pangb
Abstract
Multi-walled carbon nanotubes (MWNTs) were in-situ coated with anatase TiO2 via sol-gel process followed by annealing of the composites using infrared (IR) lamp. SEM results showed that MWNTs were coated with 15-45 nm thick TiO2 layer depending on the composite ratios. Based on the XRD results, MWNTs ...
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Multi-walled carbon nanotubes (MWNTs) were in-situ coated with anatase TiO2 via sol-gel process followed by annealing of the composites using infrared (IR) lamp. SEM results showed that MWNTs were coated with 15-45 nm thick TiO2 layer depending on the composite ratios. Based on the XRD results, MWNTs were found to show heterogeneous nucleation for anatase TiO2 and promote the formation of larger anatase TiO2 crystalline particles with higher crystalline degree. The UV-Vis- NIR characterization indicated the MWNTs also enhanced the sensitivity of TiO2 matrix for both UV and visible light, and the bond edge absorption position of the TiO2 composites shifted toward higher wavelengths with the decrease of MWNTs content. The method could be utilized to fabricate MWNTs /TiO2 composites conveniently.
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