Visible-light driven sonophotocatalytic removal of tetracycline using Ca-doped ZnO nanoparticles

Highly efficient, long-term, eco-friendly catalysts for water decontamination technology are urgently needed to meet the prioritized objectives of green development and societies worldwide. Ca-doped ZnO were investigated as environmentally friendly sono-photocatalytic system under LED visible light irradiation to efficiently mineralize tetracycline-based antibiotics. The effects of pH, Ca doping, light, ultrasound, and pH on the mineralization of tetracycline by Ca-doped ZnO nanopowders and on the chemical, sono-, photo- and sono-photostability of Ca-doped ZnO nanopowders were systematically investigated. The ZnO-based catalyst with 2 at. % of Ca dopant exhibited the best sono-photocatalytic performance in mineralizing tetracyclines under visible LED light and ultrasound irradiation (i.e., 99% mineralization in 90 min), with excellent reusability and minimal sono-photocorrosion (i.e., 1% of catalyst dissolution in 180 min), which were even greater in the absence of organic pollutants and in the pH range of most natural waters. For Ca-doped ZnO nanopowders, the role of the generated reactive oxygen species under light and ultrasound stimulation and the mechanism of the mineralization of tetracycline were analyzed. In conclusion, the sono-photocatalytic mineralization of antibiotics synergizing visible LED light and weak ultrasound irradiation in the presence of Ca-doped ZnO nanopowders presents an outstanding start to developing highly efficient, long-term, eco-friendly catalysts for efficiently treating emerging organic pollutants

Experimental Investigation to Improve the Energy Efficiency of Solar PV Panels Using Hydrophobic SiO2 Nanomaterial

This research aims to experimentally improve the overall efficiency of solar photovoltaic (PV) panels by coating them with hydrophobic SiO2 nanomaterial. Also, an accurate mathematical model was used to estimate the parameters of the PV panel, which is a non-linear optimization problem. Based on the experimental data and using the particle swarm optimization (PSO) algorithm, the optimal five parameters of a single diode model of a PV panel were determined in this study. This experimental work was conducted and carried out in the Renewable Energy Laboratory of Assiut University, Egypt. A comparative analysis was completed for three identical solar PV panels; the first panel was coated with hydrophobic SiO2 nanomaterial, so it was considered to be a self-cleaning panel; the second panel was uncoated and cleaned manually on a daily basis; and the third panel was kept dusty all the time through the experimental investigation, and was used as a reference. Experimentally, the output power of the PV panels was monitored for each panel in this study. Also, the anti-static and anti-reflection effects of coating solar PV panels with hydrophobic SiO2 nanomaterial were investigated experimentally. According to the obtained experimental results, it was found that the use of SiO2 coating for PV panels results in the better performance of the PV panels. The overall efficiency of the coated panel increased by 15% and 5%, compared to the dusty panel and the uncoated panel which was manually cleaned daily, respectively

Facile Synthesis of SnS2 Nanostructures with Different Morphologies for High-Performance Supercapacitor Applications

SnS2 is an emerging candidate for an electrode material because of the considerable interlayer spaces in its crystal structures and the large surface area. SnS2 as a photocatalyst and in lithium ion batteries has been reported. On the other hand, there are only a few reports of their supercapacitor applications. In this study, sheetlike SnS2 (SL-SnS2), flowerlike SnS2 (FL-SnS2), and ellipsoid-like SnS2 (EL-SnS2) were fabricated via a facile solvothermal route using different types of solvents. The results suggested that the FL-SnS2 exhibited better capacitive performance than the SL-SnS2 and EL-SnS2, which means that the morphology has a significant effect on the electrochemical reaction. The FL-SnS2 displayed higher supercapacitor performance with a high capacity of approximately ???431.82 F/g at a current density of 1 A/g. The remarkable electrochemical performance of the FL-SnS2 could be attributed to the large specific surface area and better average pore size. These results suggest that a suitable solvent is appropriate for the large-scale construction of SnS2 with different morphologies and also has huge potential in the practical applications of high-performance supercapacitors

Investigation of the triple peak magnetocaloric effects of Ni45Mn44Sn11 ribbons

The magnetocaloric effect (MCE) of Ni45Mn44Sn11 ribbons is simulated, with temperatures ranging from nearly 0 K to 313 K. The MCE of these ribbons exhibits triple peak behavior. Amazingly, three co-occurring peaks of both the inverse and conventional MCEs are found, one for each magnetic transition. Except for temperatures between 251 K and 273 K that correspond to an antiferromagnetic transition that shows an inverse MCE, the type of MCE in Ni45Mn44Sn11 ribbons is conventional. Consequently, materials with triple-peak MCE behavior, such as Ni45Mn44Sn11 ribbons, may provide a fascinating opportunity to obtain magnetic cooling over a wider temperature range than with conventional refrigerant materials, particularly Ni45Mn44Sn11 ribbons, which are inexpensive for use in magnetic refrigeration. Therefore, Ni45Mn44Sn11 ribbons are excellent magnetocaloric magnets for wide temperature ranges, including cryogenic and room temperatures

Fabrication of mesoporous cu films on cu foils and their applications to dopamine sensing

We previously succeeded to prepare stable mesoporous Cu films on Au-coated conductive working electrodes by using polystyrene-b-poly(oxyethylene) (PS63000-b-PEO26000) micelles as template and sulfuric acid to increase ionic conductivity. In the present study, we report the preparation of mesoporous Cu films on Cu foil. By changing the Cu salts and electrodeposition potentials, we discuss how these parameters influence the final product. Without having to filtrate interefering species, such as uric acid, ascorbic acid and glucose, the dopamine concentration can be precisely determined by applying a suitable potential. Therefore, non-invasive electrochemical sensing based on mesoporous films will be useful for daily diagnosis of mental disorder

Direct production of furfural in one-pot fashion from raw biomass using brønsted acidic ionic liquids

The conversion of raw biomass into C5-sugars and furfural was demonstrated with the one-pot method using Brønsted acidic ionic liquids (BAILs) without any mineral acids or metal halides. Various BAILs were synthesized and characterized using NMR, FT-IR, TGA, and CHNS microanalysis and were used as the catalyst for raw biomass conversion. The remarkably high yield (i.e. 88%) of C5 sugars from bagasse can be obtained using 1-methyl-3(3-sulfopropyl)-imidazolium hydrogen sulfate ([C3SO3HMIM][HSO4]) BAIL catalyst in a water medium. Similarly, the [C3SO3HMIM][HSO4] BAIL also converts the bagasse into furfural with very high yield (73%) in one-pot method using a water/toluene biphasic solvent system

Investigation on Crystal-Structure, Thermal and Electrical Properties of PVDF Nanocomposites with Cobalt Oxide and Functionalized Multi-Wall-Carbon-Nanotubes

Nanocomposites of polyvinylidene fluoride (PVDF) with dimensional (1D) cobalt oxide (Co3O4) and f-MWCNTs were prepared successfully by the solution casting method. The impact of 1D Co3O4 filler and 1D Co3O4/f-MWCNTs co-fillers on the structural, thermal, and electrical behavior of PVDF were studied. The crystal structural properties of pure PVDF and its nanocomposite films were studied by XRD, which revealed a significant enhancement of β-phase PVDF in the resulting nanocomposite films. The increase in β-phase was further revealed by the FTIR spectroscopic analysis of the samples. TG, DTA, and DSC analyses confirmed an increase in thermal stability of PVDF with the addition of nano-fillers as well as their increasing wt.%. From impedance spectroscopic studies, it was found that the DC conductivity of PVDF increases insignificantly initially (up to 0.1 wt.% of nano-fillers addition), but a significant improvement in DC conductivity was found at higher concentrations of the nano-fillers. Furthermore, it was observed that the DC conductivity decreases with frequency. The increase in DC conductivity corresponded to the strong interactions of nano-fillers with PVDF polymer chains

Synthesis of nanosized composite powders via a wet chemical process for sintering high performance W-Y2O3 alloy

With the aim of preparing high performance oxide dispersion strengthened tungsten-based alloys by powder metallurgy, the W-Y2O3 composite nanopowders were prepared by an improved bottom-up wet chemical method. Ultrasonic treatment and anionic surfactant sodium dodecyl sulfate (SDS) addition were innovatively introduced into this wet chemical method in order to fabricate homogeneous, ultrafine W-Y2O3 composite nanopowders. As a result, the average tungsten grain size of 40-50 nm was obtained for this composite nano powders. For comparison, W-Y2O3 composite powders were also prepared by traditional mechanical milling. After that, spark plasma sintering (SPS) was employed to consolidate the powders prepared by either mechanical milling or wet chemical method to yield high density as well as suppress grain growth. It is found that the W-Y2O3 alloy prepared by wet chemical method and subsequent SPS possesses smaller grain size (0.76 +/- 0.17 mu m) and higher relative density (99.0%) than that prepared by mechanical milling and subsequent SPS. Moreover, the oxide nanoparticles (about 2-10 nm) are dispersed within tungsten grains and at grain boundaries more uniformly in W-Y2O3 alloy prepared by wet chemical method and subsequent SPS. Due to the ultrafine grains, high sintering density and homogeneously distributed oxide nanoparticles, the Vickers microhardness of yttria dispersion strengthened tungsten-based alloy prepared in our work reaches up to 598.7 +/- 7.3 HV0.2, higher than that reported in the previous studies. These results indicate that the improved bottom-up wet chemical method combined with ultrasonic treatment and anionic surfactant addition developed in our work is a promising way to fabricate high performance oxide dispersion strengthened tungsten-based alloys with ultrafine grain and high density

Facile Synthesis of SnS₂ Nanostructures with Different Morphologies for High-Performance Supercapacitor Applications

SnS₂ is an emerging candidate for an electrode material because of the considerable interlayer spaces in its crystal structures and the large surface area. SnS₂ as a photocatalyst and in lithium ion batteries has been reported. On the other hand, there are only a few reports of their supercapacitor applications. In this study, sheetlike SnS₂ (SL-SnS₂), flowerlike SnS₂ (FL-SnS₂), and ellipsoid-like SnS₂ (EL-SnS₂) were fabricated via a facile solvothermal route using different types of solvents. The results suggested that the FL-SnS₂ exhibited better capacitive performance than the SL-SnS₂ and EL-SnS₂, which means that the morphology has a significant effect on the electrochemical reaction. The FL-SnS₂ displayed higher supercapacitor performance with a high capacity of approximately ∼431.82 F/g at a current density of 1 A/g. The remarkable electrochemical performance of the FL-SnS₂ could be attributed to the large specific surface area and better average pore size. These results suggest that a suitable solvent is appropriate for the large-scale construction of SnS₂ with different morphologies and also has huge potential in the practical applications of high-performance supercapacitors