Ghader Hosseinzadeh
Abstract
In the current study, for the first time, an innovative hydrothermal method was proposed for the synthesis of TiO2/WO3 heterojunction nanocomposite from the combination of TiO2 nanorod, and WO3 nanoflakes. Because of environmental issues arising from the vast use of insecticides, this nanocomposite photocatalyst ...
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In the current study, for the first time, an innovative hydrothermal method was proposed for the synthesis of TiO2/WO3 heterojunction nanocomposite from the combination of TiO2 nanorod, and WO3 nanoflakes. Because of environmental issues arising from the vast use of insecticides, this nanocomposite photocatalyst was applied for the first time for photocatalytic degradation of Nitenpyram insecticide under visible light irradiation. The prepared nanocomposite was fully characterized by XRD, FESEM, DRS, PL, and Mott-Schottky analysis. The results revealed that the heterojunction sample had the best photocatalytic performance. The enhanced photocatalytic activity of this heterojunction is attributed to the decrease of the charge carrier’s recombination rate and enhanced visible light harvesting. Moreover, based on the radical trapping experiments and Mott-Schottky calculations, hydroxide radical was determined as the main active species for decomposition of Nitenpyram insecticide, and type II charge transfer mechanism was revealed to be responsible for the enhanced photocatalytic performance, which charge transfer between the two semiconductors results in the decreasing of the charge carrier’s recombination rate.
Mahta Nazari; Bita Ayati
Abstract
This study was conducted to evaluate sodium dodecyl benzene sulfonate removal using electrocoagulation/flotation and photocatalytic nano-TiO2 slurry systems. The parameters which are effective on the surfactant removal were investigated and optimized. Electrocoagulation/flotation system included meshed ...
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This study was conducted to evaluate sodium dodecyl benzene sulfonate removal using electrocoagulation/flotation and photocatalytic nano-TiO2 slurry systems. The parameters which are effective on the surfactant removal were investigated and optimized. Electrocoagulation/flotation system included meshed and mono-polar stainless steel electrodes which installed horizontally. According to the results, after 60 minutes in pH of 8, electrodes distance of 1 cm, initial SDBS concentration of 750 mg/L, SDBS and COD removal rates were achieved to 93.54 and 90%, respectively. In photocatalytic system, during 48 h, SDBS and COD removed 98.7 and 95%, respectively, while pH was around 8, initial concentration of SDBS was 300 mg/L and nano-TiO2 particles concentration was 0.5 mg/L. In the hybrid system, after 12 minutes, SDBS concentration reached to 329 mg/L which entered to the photocatalytic system that resulted in SDBS and COD removal efficiency of 99 and 96.27%, respectively. Compared to the single systems, by using the hybrid system, the removal efficiencies were improved.
Amirali Abbasi; Jaber Jahanbin Sardroodi; Alireza Rastkar Ebrahimzadeh
Abstract
First-principles calculations within density functional theory (DFT) have been performed to investigate the interactions of NO2 molecules with TiO2/Gold nanocomposites in order to completely exploit the adsorption properties of these nanostructures. Given the need to further comprehend the behavior of ...
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First-principles calculations within density functional theory (DFT) have been performed to investigate the interactions of NO2 molecules with TiO2/Gold nanocomposites in order to completely exploit the adsorption properties of these nanostructures. Given the need to further comprehend the behavior of the NO2 molecules positioned between the TiO2 nanoparticle and Au monolayer, we have geometrically optimized the complex systems consisting of the NO2 molecule oriented at appropriate positions between the nanoparticle and Au monolayer. The structural properties such as bond lengths, bond angles, adsorption energies and Mulliken population analysis and the electronic properties including the density of states and molecular orbitals have been also analyzed in detail. The results indicate that the interaction between NO2 and undoped TiO2-N/Gold nanocomposites is stronger than that between gas molecules and N-doped TiO2/Gold nanocomposites, which reveals that the pristine nanocomposite can react with NO2 molecule more efficiently. Therefore, the obtained results also suggest a theoretical basis for the potential applications of TiO2/Gold nanocomposites in gas sensing, which could help in the developing of novel TiO2 based advanced sensor devices.