Papers by Keyword: TiO₂ Nanoparticle

Abstract: This study aimed to evaluate filter efficiency for TiO₂ nanoparticle deposition across varied water chemistry and simulated conditions. The experimental results provided collision attachment efficiencies (α) of 0.001, 0.002, and 0.01 and filter coefficients (λ) of -0.003, -0.01, and -0.02. The authors used these collision attachment efficiencies to assess filter efficacy under simulated conditions, mainly removing naturally occurring nanoparticles spanning sizes from 1 to 100 nm. This experiment uncovered a strong correlation between TiO₂ nanoparticle deposition and water ionic strength, with aggregation becoming more pronounced as ionic strength increased. This phenomenon was especially prominent in instances lacking alum addition. Notably, the presence of alum resulted in the nanoparticles maintaining a dispersed state in the water, attaining enhanced stability by introducing excessive positive charges. Consequently, this study underscores how manipulating water's ionic strength can effectively induce nanoparticle destabilization during filtration. The implications of these findings are significant, as practical data about the behavior of diminutive like TiO₂ nanoparticles has been notably lacking.

Abstract: A nanostructured solar cells consist of a nonporous n-type TiO₂ nanoparticles and a p-type semiconductor Cu₂ZnSnS₄ (CZTS) thin film has been numerically simulated using SCAPS-1D tool. The performed theoretically analysis is compared with the experimental reported data. The band diagram, IV characteristics and quantum efficiency of this structure is considered. The benefit of both TiO₂ and CZTS material leads to more than 10% conversion efficiency which is promising between the nanoparticle-based heterojunbctions proposed for PV applications.

Abstract: Hybrid structure of TiO₂ nanofiber and nanoparticle as a photoelectrode was very attractive in dye-sensitized solar cells (DSCs) because TiO₂ nanoparticle provided a high specific surface area to adsorb the N719 dye and TiO₂ nanofiber was a direct path to transfer photoelectron from dye to electrode. TiO₂ nanofiber film was prepared with titanium-tetraisopropoxide (TTIP) and polyvinylpyrrolidone (PVP) based precursor by electro-spinning process. To fabricate the hybrid structure, TiO₂ nanoparticular paste was screen printed on the TiO₂ nanofiber film. Electrospun TiO₂ nanofiber film and screen printed TiO₂ nanoparticular film were combined in layer by layer method. These films were observed as an anatase phase by X-ray diffraction pattern. Thickness and diameter of TiO₂ nanofibers were ~5μm and ~400nm, respectively. Thickness and particle size of TiO₂ particles were ~5μm and ~20nm, respectively. Compared to conventional DSCs, higher short circuit current densities (Jsc) of 6.47 mA/cm² and higher power conversion efficiency of 3.06 % were measured in DSCs having hybrid structure of TiO₂ nanofiber and nanoparticle. Electrochemical impedance spectroscopy (EIS) was observed to understand an electron transfer and life time.

Abstract: Hybrid structure of TiO₂ nanofiber and nanoparticle as a photoelectrode was very attractive in dye-sensitized solar cells (DSCs) because TiO₂ nanoparticle provided a high specific surface area to adsorb the N719 dye and TiO₂ nanofiber was a direct path to transfer photoelectron from dye to electrode. TiO₂ nanofiber film was prepared with titanium-tetraisopropoxide (TTIP) and polyvinylpyrrolidone (PVP) based precursor by electro-spinning process. To fabricate the hybrid structure, TiO₂ nanoparticular paste was screen printed on the TiO₂ nanofiber film. Electrospun TiO₂ nanofiber film and screen printed TiO₂ nanoparticular film were combined in layer by layer method. These films were observed as an anatase phase by X-ray diffraction pattern. Thickness and diameter of TiO₂ nanofibers were ~5μm and ~400nm, respectively. Thickness and particle size of TiO₂ particles were ~5μm and ~20nm, respectively. Compared to conventional DSCs, higher short circuit current densities (Jsc) of 6.47 mA/cm² and higher power conversion efficiency of 3.06 % were measured in DSCs having hybrid structure of TiO₂ nanofiber and nanoparticle. Electrochemical impedance spectroscopy (EIS) was observed to understand an electron transfer and life time.

Abstract: The absence of cracks and a high optical transparency are critical factors for obtaining high performance when TiO₂ thin films are used as cathodes in dye-sensitized solar cells (DSSCs). Synthesized and classified TiO₂ nanoparticles were deposited by constant-current electrophoresis in ethanol. The optical transparency of thin films and the DSSC efficiency increased rapidly with decreasing particle size and increasing film homogeneity. This increase in the DSSC efficiency suggests that the electron conduction path in a thin film consists of connections in the crystal lattice formed between TiO₂ nanoparticles. This formation of connections increases the electron diffusion length.

Abstract: Chrome-free Dacromet coating is a green anti-corrosion technology. This paper studied the effects of nanoparticles of TiO2 and SiO2 on the coatings. The results shown the addition of nano-TiO2 (T-coating )improved the physical properties and corrosion resistance. The addition of nano-SiO2 (S-coating )was week bonded with zinc and aluminium powders, resulting in the poor properties.

Abstract: By using organic amine as the soft template, TiO₂ nanostructured thin films have been deposited on the surface of short glass fibers (SGFs) by biomimetic synthesis technology at low temperature (85°C). The properties of composite particles, including surface morphology, the phase composition of the coating layer and microstructure were characterized by SEM, XRD, XPS and Raman. The results show that the functional layers containing NH₂ and OH groups can be formed through a kind of organic amine, which can induce the bio-mineralization of nano-TiO₂ on the SGFs surfaces. The XRD shows that TiO₂ thin films uniformly coated on SGFs surfaces were mainly anatase. The surface roughness of SGFs was remarkably increased after coating. Compared with uncoated SGFs as filler, the abrasive loss of composite coatings decreased to 47 percent of that coatings filled with uncoated SGFs, when the composite fiber powders were filled in wear-resistant coatings based on the silicone modified epoxy resins. Therefore, anti-wear property of coatings was notably enhanced.

Abstract: By using tetrabutyl titanate as the main material, TiO₂ nanoparticles / CNTs composite particles have been prepared in acidic abundant aqueous solution at low temperature without calcination. The microstructure of the composite particles, including surface morphology, phase composition and specific surface area was characterized by SEM, TEM, Raman, XPS and BET. The results reveal that TiO₂ nanoparticles coated uniformly on CNTs surfaces were mainly anatase type. The surface roughness of CNTs was remarkably increased after coating. However, the specific surface area of composite particles decreased by 23.4 m²•g^-1 than that of CNTs with uncoated TiO₂. Photocatalytic activity of TiO₂ nanoparticles / CNTs composite particles shows a significant increase of absorption intensity both in ultraviolet band and visible light band according to UV-vis spectra.

Abstract: The wastewater from the coir, pharmaceutical, leather, paper and pulp industries is contaminated with water-soluble poly phenolic compounds (tannins). Among various tannins, tannic acid is a typical hydrolysable tannin prevalent in wastewater. The degradation of tannic acid using TiO₂ nanoparticles as photocatalyst was investigated. The effect of catalyst concentration, pH of aqueous suspension and also electron acceptors such as hydrogen peroxide (H₂O₂) and ozone (O₃) on the degradation of tannic acid was studied. The degradation of tannic acid was found to be more efficient and complete in the presence of UV/TiO₂/O₃ compared to UV/TiO₂/H₂O₂. The kinetics of degradation was observed to follow first order rate equation which indicates that the mineralization process is diffusion controlled.

Abstract: This paper mainly studied the effects of different iron-doped volume on photo-catalytic oxidation of TiO2 for mercury removal. Through the photocatalytic oxidation system, we evaluated the elemental mercury removal performance of TiO2 with iron-doped mass ratio of 0.5%, 1%, 2% and 3%. While the iron-doped mass ratio were 0.5%, 1%, 2% and 3%, the elemental mercury removal efficiency were 70.83%，52.89%，72.32% and 62.39% respectively, the removal efficiency increased firstly, then declined, and 2% iron-doped was the most appropriate