9 research outputs found
Physical, chemical, and biological routes of synthetic titanium dioxide nanoparticles and their crucial role in temperature stress tolerance in plants
Nanotechnology is attracting significant attention worldwide due to its applicability across various sectors. Titanium dioxide nanoparticles (TiO2NPs) are among the key nanoparticles (NPs) that have gained extensive practical use and can be synthesized through a wide range of physical, chemical, and green approaches. However, TiO2NPs have attracted a significant deal of interest due to the increasing demand for enhancing the endurance to abiotic stresses such as temperature stress. In this article, we discuss the effects of temperature stresses such as low (4 °C) and high temperatures (35 °C) on TiO2NPs. Due to climate change, low and high temperature stress impair plant growth and development. However, there are still many aspects of how plants respond to low and high temperature stress and how they influence plant growth under TiO2NPs treatments which are poorly understood. TiO2NPs can be utilized efficiently for plant growth and development, particularly under temperature stress, however the response varies according to type, size, shape, dose, exposure time, metal species, and other variables. It has been demonstrated that TiO2NPs are effective at enhancing the photosynthetic and antioxidant systems of plants under temperature stress. This analysis also identifies key knowledge gaps and possible future perspectives for the reliable application of TiO2NPs to plants under abiotic stress
Effects of annealing temperature on the phase formation, optical, photoluminescence and magnetic properties of sol-gel YFeO3 films
YFeO3 (YFO) thin films were deposited onto quartz substrates via sol-gel spin-coating technique and annealed at different temperature ranged between 650 and 900 °C. The impact of annealing temperature on the phase formation, microstructural, optical, photoluminescence (PL) and magnetic properties of the films were systematically investigated. X-ray diffraction analysis revealed an amorphous structure in film annealed at 650 °C and formation of hexagonal-YFO (h-YFO) phase in films annealed at 750–800 °C. The films annealed at 850–900 °C exhibited an orthorhombic-YFO (o-YFO) structure. Atomic force microscopy images of h-YFO films showed homogeneous surface with uniform particles size and shape. The particle size increased and had irregular shape in o-YFO films. The average particle size was 44 and 117 nm, while the root square roughness was 1.38 and 2.55 nm for h- and o-YFO films annealed at 750 and 850 °C, respectively. The optical band gap (Eg) was 2.53 and 2.86 eV for h- and o-YFO films annealed at 750 and 850 °C, respectively. The PL spectra of h-YFO films were red-shifted compared with that of o-YFO films. The PL emission related to near band edge was observed at 459.0 and 441.9 nm for h- and o-YFO films annealed at 750 and 850 °C, respectively. The magnetization was enhanced with the increasing of annealing temperature and has the value of 4.8 and 12.5 emu/cm3 at 5000 Oe for h- and o-YFO films annealed at 750 and 850 °C, respectively
Numerical analysis of magneto-radiated annular fin natural-convective heat transfer performance using advanced ternary nanofluid considering shape factors with heating source
Applications: The fins performance under natural convection is essential to make it more functional for large scale applications more specifically in thermal engineering. For this, it is important to introduce new techniques to enhance the fins performance instead of traditional way. Thus, this study introduces a new way to make the fin more efficient using ternary nanomaterial under nanoparticles shape factor. The annular fin significantly contributes in electronics to exhaust the hot air, injector pumps and applied thermal engineering. Purpose: and Methodology: This work focuses on the fin energy model using shape factors. Therefore, the ternary nanofluid, natural convection, thermal radiation and magnetic field used to develop the model. Then, the RKF-45 implemented to investigate physical results. Core findings: Keen analysis of the physical results reveal that the coefficient of thermal conductivity ranging from 0.0% < α1 < 3.0% and natural convection have major role in the fins energy performance. Induction of magnetic field and thermal radiation Rd are reliable for the fin cooling and, heating source Q1 = 0.2,0.4,0.6,0.8 promote the fin energy capability in the existence of (Al2O3–CuO–Cu) ternary nanomaterial with concentration factor up to 2%. On the comparative basis, ternary nanomaterial makes the fin more efficient than hybrid nanomaterial
Crystal growth, optical, photoluminescence and magnetic properties of sol-gel GdFeO3 thin film
GdFeO3 (GFO) orthoferrite is a perovskite structured material with rich physical properties. In this work, crystal growth, electronic, optical, photoluminescence (PL) and magnetic properties of sol-gel synthesized GFO thin films onto quartz substrate were investigated. The films were annealed at various temperature 650–900 °C. XRD results showed transformation from an amorphous to nanocrystalline GFO and GdO secondary phase with rise of annealing temperature from 650 to 700 °C. Single phase GFO was observed in films annealed above 700 °C. Crystallite size of the films gradually increased from 10.5 to 89.9 nm for films annealed from 700 to 900 °C, respectively. The surface morphology changed from porous microstructure consisted of tiny particulates in film annealed at 700 °C into enlarged particles and clear polycrystalline structure in films annealed above 700 °C. From XPS spectra analysis, both Fe and Gd ions existed in a 3+ valence state. The films demonstrated optical band gap ranged between 2.8 and 3 eV. The PL spectra obtained using a 300 nm excitation wavelength consisted of four emission peaks. The near band edge emission of the films varied between 449.9 and 455.1 nm. The films showed weak ferromagnetic behavior with magnetization ranging from 24 to 49 emu/cm3
Monodispersed NiO Nanoparticles into SBA-15: An Efficient Nanocatalyst to Produce Ketone-Alcohol (KA) Oil by the Oxidation of Cyclohexane in Mild Conditions
A simple and efficient approach to preparing highly efficient and reusable NiO@SBA-15 nanocatalysts for the oxidation of cyclohexane to produce ketone-alcohol (KA) oil was reported. These nanocatalysts were prepared by the dispersion of NiO NPs into SBA-15 using a coordination-assisted grafting method. In this approach, four commercially available nickel salts were immobilized into amino-functionalized SBA-15. After washing and calcination, four new nanocatalysts were obtained. The high dispersion of NiO NPs into SBA-15 was confirmed by HR-TEM and XRD. Different oxidants such as O2, H2O2, t-butyl hydrogen peroxide (TBHP), and meta-Chloroperoxybenzoic acid (m-CPBA) were evaluated. However, m-CPBA exhibited the highest catalytic activity. Compared to different catalysts reported in the literature, for the first time, 75–99% of cyclohexane was converted to KA oil over NiO@SBA-15. In addition, the cyclohexane conversion and K/A ratio were affected by the reaction time, catalyst dose, Ni content, and NiO dispersion. Moreover, NiO@SBA-15 maintained a high catalytic activity during five successive cycles
Towards a promising systematic approach to the synthesis of CZTS solar cells
Abstract This study aims to enhance the CZTS device's overall efficiency, the key research area has been identified in this study is to explore the effects of a novel, low-cost, and simplified, deposition method to improve the optoelectronic properties of the buffer layer in the fabrication of CZTS thin film solar cells. Herein, an effective way of addressing this challenge is through adjusting the absorbers' structure by the concept of doping, sensitized CdS thin film by the bi-functional linker, and an environmentally friendly catalytic green agent. The Linker Assisted and Chemical Bath Deposition (LA-CBD) method was introduced as an innovative and effective hybrid sensitization approach. In the one-step synthesis process, Salvia dye, Ag, and 3-Mercaptopropionic acid (MPA) were used. Generally, the results for all samples displayed varying bandgap as achieved between (2.21–2.46) eV, hexagonal structure with considerably decreased strain level, broader grain size, and dramatically enhanced crystalline property. Hence, the rudimentary CdS/CZTS solar cell devices were fabricated for the application of these novel CdS films. Preliminary CZTS thin film solar cell fabrication results in the highest conversion efficiency of 0.266% obtained CdS + Salvia dye, indicating the potential use of the CdS films as a buffer layer for CZTS photovoltaic devices
Effect of chenodeoxycholic acid on the performance of dye-sensitized solar cells utilizing pinang palm (Areca catechu) dye
This study examined and described the optical and photovoltaic (PV) characterizations of the Fruit Areca catechu
(pinang) as a new type of organic sensitizer. Recent reports stated that including chenodeoxycholic acid (CDCA) in
the dye improves the performance of dye-sensitized solar cells (DSSCs). The effectiveness of PV dye was investigated
by applying it in a DSSC. The absorption spectra indicated that natural dyes with CDCA has an excellent stabilizing
ability. The Fourier-transform infrared spectra indicated the existence of carboxylic and hydroxyl functional groups
in the naturally extracted dye. These functional groups were responsible for the rapid electron transfer and strong
electronic linkages of interactions within the TiO2
surface. In this study, photoluminescence spectra analysis showed
that by narrowing the bandgap, incorporating CDCA as a co-adsorbent in natural dye could generate a significant
photocurrent. The overall power conversion efficiency was enhanced by 4.6%. Moreover, the cell efficiency reached
up to 0.076% after adding 1.5 mM of CDCA without optimizing the sensitization time. Results demonstrated that the
present study contributes toward the improvement of DSSC through efficient electron injection
Recent progress in performance improvement strategies for quantum dot sensitization methods: Challenges, achievements, and future prospects
In the recent past, there has been an increase in the use of semiconductor nanostructures that convert solar energy to electrical energy. This has encouraged the development of better and more efficient solar cells (SCs). Numerous investigations have been conducted into synthesizing novel semiconductor materials and tuning the electronic properties based on the shape, size, composition, and assembly of the quantum dots to improve hybrid assemblies. Recent studies that are determining the prospects of quantum dot SCs can form the basis for improving photovoltaic efficiency. Here, we have reviewed studies that investigated the sensitization methods for fabricating highly efficient SCs. We also discussed some examples that would help other researchers who want to sensitize quantum dot (QD) SCs. Thereafter, we analyzed the main and popular strategies that can be used for sensitizing the QD SCs within the limitations, advantages, and prospects of fabricating high-efficiency and stable QDs. During this work, we offered strong technical support and a theoretical basis for improving the industrial applications of QD. In addition, we provide a reference that can inspire other researchers who aim to improve the performance of SCs