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Cytotoxic Effects of Titanium Dioxide Nanaoparticles Synthesized by Laser Technique on Peripheral Blood Lymphocytes and Hep-2 Cell Line
摘要： Objective: This study assay the toxic effects of titani-um dioxide nanoparticles (TiO2NPs) on peripheral blood lymphocytes and Hep-2 cell by measuring Mitotic Index (MI), Blastogenic Index (BI), Total Chromosomal Aberration (TCA) and growth rate of cancer cells. Methods: TiO2NPs were synthesized using laser tech-nique by ablation of titanium target immersed in dis-tilled de-ionized water (DDW) using Q-switched pulsed Nd:YAG laser with repetition rate of 1 Hz, wavelength of 1064 nm, 300 pulses and energy of 400 mJ. Chro-mosomal analyses were carried out at different con-centrations of synthesized TiO2 NPs (0.0, 45, 90, and 180) μg/mL. Results: X-ray diffraction (XRD) exhibited anatase phase of prepared TiO2NPs and showed that the crys-talline structures of TiO2NPs is tetragonal. Absorption spectrum of TiO2 NPs was at ultraviolet-region 215 nm due to Surface Plasmon Resonance (SPR), and the par-ticles size distribution of the prepared TiO2NPs ranged from 40 to 110 nm. Finding showed that both MI and BI suffered from high reduction while TCA suffered from significant elevation represented by Chromatid Breaks (CB), Micronuclei (MN) and Ring Chromosome (RC). The highest proportion of (TCA) has been observed in 180 μg/mL of TiO2NPs, (significant at p≤0.05). while the toxic effects of prepared TiO2NPs on Hep-2 cell line represent decline in growth rate with an increase in concentration of TiO2NPs with malformation in the cell structure and shape and placement of the nucleus. Conclusion: The ablation via Q-switched Nd: YAG laser has adequacy to prepare TiO2NPs with 215 nm absorption spectrum, nearly spherical particles and suitable particle size (40-110 nm). In vitro assay showed that prepared TiO2 NPs have significant cytotoxic effects on peripheral blood lymphocyte and Hep-2 cell line by reduction in both Mitotic index (MI) and blasto-genic index (BI) and growth rate of cancer cells.
关键词： Titanium Dioxide Nanaoparticles,Hep-2 cell line,Mitotic Index,Q-switched pulsed Nd:YAG laser,Chromosomal Aberration,Blastogenic Index
更新于2025-09-12 10:27:22
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Controlled transition of microcapsules from coil conformation to globule during the expansion of the pulse jet of nanoparticle suspension of TiO2 in supercritical (CO2) polyethylene glycol solution
摘要： The process of microencapsulation of titanium dioxide nanoparticles during the expansion of a supersonic jet of TiO2 suspension in a solution of polyethylene glycol (PEG 8000) in supercritical CO2 into a vacuum and background gas (helium) has been studied experimentally. The dependence of the position of the microcapsule transition point on the jet axis from the coil to a globular conformation on the temperature in the reactor and on the pressure of the background gas at different co-solvent concentrations has been established. A “coil?globule” re-entrant transition has been recorded at a greater distance from the nozzle exit than the point of collapse.
关键词： supersonic jet,polyethylene glycol,microencapsulation,supercritical CO2,coil-globule transition,titanium dioxide
更新于2025-09-12 10:27:22
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Simultaneously efficient light absorption and charge transport of CdS/TiO2 nanotube array toward improved photoelectrochemical performance
摘要： CdS has been widely used to modify TiO2-based photoanodes for photoelectrochemical (PEC) water splitting. Due to the poor interface contact between chalcogenides and oxides, however, such CdS modified TiO2 materials usually exhibit inefficient separation and transport of charges, leading to an unsatisfactory efficiency during the PEC water splitting process. Addressing this issue, we herein report a CdS/TiO2 nanotube array (CdS/TNA) photoanode that was fabricated through a successive ion layer absorption and reaction (SILAR) method with an additional subsequent annealing. This post-annealing process is essential to enhance the interface contact between the CdS and the TNAs, resulting in an accelerated transfer of photogenerated electrons from the CdS to the TNAs. In addition, the post-annealing also improves the light absorption capability of the CdS/TNA photoanode. The simultaneous enhancement of charge transport and light absorption provided by the post-annealing is essential for improving the PEC performance of the CdS/TNA photoanode. The CdS/TNA photoanode obtained by this strategy exhibits a much enhanced PEC performance in water splitting, and its photocurrent density and solar-to-hydrogen conversion efficiency could reach 4.56 mA cm?2 at 1.23 V vs. reversible hydrogen electrode and 5.61%, respectively. This simple but effective route can provide a general strategy for obtaining high-performance oxide-based photoelectrodes.
关键词： Photoelectrochemical water splitting,Nanotube arrays,Titanium dioxide,Cadmium sulfide
更新于2025-09-12 10:27:22
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<i>Ab initio</i> study of temperature- and laser-induced phase transitions in
摘要： We analyze the bulk phase transitions of the three titanium dioxide polymorphs anatase, rutile, and brookite in thermodynamical equilibrium and after ultrafast laser excitation using the generalized solid-state nudged elastic band (G-SSNEB) method. For calculating the forces and stresses needed for G-SSNEB, we use electronic-temperature dependent density functional theory calculations. Our results show that the anatase-rutile and brookite-rutile phase transitions have a considerably lower energy barrier than the anatase-brookite phase transition in the thermodynamical equilibrium and upon laser excitation. The obtained transition temperatures in thermodynamical equilibrium are consistent with experimentally observed ones. Furthermore, our calculations show that the pathways of the phase transition are not affected considerably by the applied laser pulse. Although the pathways do not change considerably we see that the rutile phase is stabilized by the laser pulse.
关键词： phase transitions,density functional theory,G-SSNEB method,titanium dioxide,laser excitation
更新于2025-09-12 10:27:22
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Luminescent europium-doped titania for efficiency and UV-stability enhancement of planar perovskite solar cells
摘要： Perovskite solar cells (PSCs) have demonstrated high power conversion efficiencies (PCEs) but poor stability against ultraviolet (UV) irradiation. Here, we report a one-pot synthesized luminescent europium-doped titania (Eu-TiO2) via chemical-bath deposition at low-temperature (70 oC) for planar PSCs, which enables simultaneous efficiency and UV-stability enhancement. We show that the Eu-TiO2 could effectively convert damaging UV photons into useful visible luminescence for additional light harvesting. A more optimal energy band alignment at the Eu-TiO2/perovskite interface leads to facilitated charge extraction and suppressed non-radiative recombination. The use of Eu-TiO2 in PSCs results in increased photocurrent and open-circuit voltage, yielding an enhanced PCE of 21.40% with relative to pristine TiO2 device (19.22%). More importantly, the Eu-TiO2 devices exhibit remarkably improved UV stability, retaining 75% of the initial PCE after exposing to UV illumination for 500 hours, while the devices with pristine TiO2 lost the majority of their original PCEs in 150 hours. As a proof-of-concept, we further demonstrate the scalability of our method by fabricating a large-area Eu-TiO2 film of 64 cm2 showing excellent uniformity.
关键词： band alignment,planar perovskite solar cells,down-shifting,europium-doped titanium dioxide,UV stability
更新于2025-09-12 10:27:22
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A Method for Estimating the Functionality of TiO2/Quantum Dot Multilayer Hybrid Structures Based on the Generation of Reactive Oxygen Species
摘要： A new technique for estimating the efficiency of electron transfer from a CdSe/ZnS quantum dot (QD) to TiO2 nanoparticles based on the generation of reactive oxygen species by hybrid structures is presented. It was demonstrated that in the formed multilayer hybrid structures of TiO2/QD, photoinduced electron transfer is realized with an efficiency of 26%.
关键词： hybrid structures,photoinduced electron transfer,semiconductor quantum dots,titanium dioxide nanoparticles,reactive oxygen species
更新于2025-09-12 10:27:22
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Comparison of Efficiency analysis of Perovskite solar cell by altering Electron and Hole transporting layers
摘要： The methylamine lead halide perovskites as the light harvesting material in solar devices are emerging and promising due to their easy manufacturing process and large photovoltaic efficiency. Generally perovskite solar cells consist of a structure in which the perovskite light absorbing layer is sandwiched between electron and hole transporting layers (ETLs and HTLs). Herein we report four types of perovskite (CH3NH3PbBr3) solar cells which were fabricated in the absence and presence of electron transporting layer (Titanium dioxide (TiO2)) and hole transporting layer (2,2',7,7'-Tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-pirobifluorene (Spiro-OMeTAD)). Efficiency comparison analysis of fabricated solar cells was performed in the absence and presence of electron and hole transporting layers. All layers were deposited by spin-coating method. Different analysis using XRD, SEM, UV and IV measurements were carried out for all samples. Maximum power conversion efficiency of 13.8 % was obtained.
关键词： Hole transport material free,mesoporous Titanium dioxide,Perovskite solar cell,photovoltaic technology
更新于2025-09-12 10:27:22
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Co‐Electrodeposition of Sn‐Doped TiO <sub/>2</sub> Electron‐Transporting Layer for Perovskite Solar Cells
摘要： Sn-doped TiO2 films are successfully co-electrodeposited from a single bath containing TiCl3 and SnCl2, providing a new and facile method for the preparation of metal doped TiO2 thin films. Through systematic examinations on the film morphologies, optical and electronic properties of the electrodeposited TiO2 films with different Sn doping amount, it is utilized as the electron-transporting layer (ETL) in a perovskite solar cell (PSC). The photovoltaic performance of PSCs equipped with electrodeposited Sn-doped TiO2 ETL is improved considerably, which is mainly attributed to the increased carrier concentration and improved electron extraction capability due to Sn-doping. Currently, power conversion efficiency of planar type PSC using 5 % (molar ratio) Sn-doped TiO2 ETL achieves 16.8 %, corresponding a 9.8 % improvement when comparing with the sample using pure TiO2 (15.3 %).
关键词： Electron-transporting layer,Titanium dioxide,Metal-doping,Perovskite solar cell,Electrodeposition
更新于2025-09-12 10:27:22
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Titanium dioxide-based picoseconds pulsed fiber laser performances comparison in the 1.5-micron region
摘要： We demonstrated and compared picoseconds pulsed fiber lasers based on Titanium dioxide based saturable absorbers (SAs); 20 cm long Titanium dioxide-doped fiber (TiO2DF) and Titanium dioxide PVA film (TiO2PF) in the 1.5-micron region. The laser cavity utilized 2.4 m long Erbium-doped fiber (EDF) as the gain medium. A self-starting pulsed laser with a consistent repetition rate of ~1 MHz emerged stably with the incorporation of TiO2 based SAs. The TiO2DF SA produced 9.74 ps pulsed laser at a central wavelength of 1553 nm within a pump power range of 106-142 mW. The fiber SA promoted slightly higher slope efficiency and maximum pulse energy of 13.17% and 8.56 nJ, respectively in comparison with the film SA. On the other hand, the TiO2PF SA generated stable 3.89 ps pulsed laser at an operating wavelength of 1560 nm within 86-142 mW pump power range. The film SA also produced slightly greater maximum output power of 12.17 mW and maximum peak power of 3.43 kW, respectively at the maximum pump power. The results confirmed that both TiO2 SAs can be good alternative pulse modulator in the 1.5-micron region.
关键词： Titanium dioxide,fiber saturable absorber,Optical fiber laser,thin film
更新于2025-09-12 10:27:22
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Dye-Sensitized Solar Cells Using Natural Dye as Light-Harvesting Material Extracted From the Leaves of Peltophoroum Pterocarpum
摘要： The Dye Sensitized Solar Cell (DSSC) was fabricated using the dye extracted from the leaves of Peltophorum pterocarpum. The dye was extracted using cold extraction with ethanol and water. The absorption nature of the extracted dye was analyzed using UV-Vis spectrometer. The structural property of the pure titanium dioxide (TiO2) nanoparticles was analyzed using powder X-ray diffraction (PXRD). The Surface morphology of the synthesized pure TiO2 nanoparticles was identified with high resolution scanning electron microscopy (HRSEM) analysis. The TiO2 films were coated on Fluorine doped Tin Oxide (FTO) using doctor blade method. The current - voltage character of the prepared DSSC are measured. From the J-V characteristic curves of cells, the parameters related to the solar cell performance were calculated. Natural dye is biodegradable and non-toxic having most of the extraction process harmless to environment. In addition, natural dye has the promising future as it is abundant.
关键词： Peltophorum pterocarpum,Natural dye,Titanium dioxide,HRSEM,DSSC
更新于2025-09-12 10:27:22