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Water contamination is a significant issue in the modern day, caused by the textile dying business, and it has a detrimental impact on living organisms. We report on the manufacture of gold-doped ZnO nanospheres using a simple heat treatment approach and the use of ZnO nanoparticles as photocatalysts for the degradation of methyl orange dye. To increase this degrading activity, Au was utilised as a modifier, and their temperature quenching effect was noticed. One of the most efficient electron grabbers in the conduction band is Au ion. The novelty of this recent research is that it has found that anatase to rutile phase transformation is promoted, and the highest transformation was achieved by using 1.0% of Au, which proves Au-doped ZnO-based nanoparticles are best for this degradation of dyes. The structural, morphological, optical, electrical, and photocatalytic characteristics of the synthesised nanocatalysts were determined. These nanoparticles have a grain size of 45-75 nm. Photocatalytic activity was investigated using UV-Vis spectra, and a significant absorption peak of about 482 nm was discovered. With increasing frequency, the dielectric constant and frequency of the produced nanoparticles drop. The kinetic analysis yields a rate constant of 0.0165 min-1 for nanosphere-like particles. At a concentration of 1% Au, the produced nanoparticles degrade the dye completely in 150 minutes when exposed to UV light. [ABSTRACT FROM AUTHOR]

In today's world of electronics, nanomaterial applications pose a challenge. The spin coating approach was used to create nanostructured ZnO with wurtzite structure in a recent study. Antimony doping, aluminum, and antimony codoping with 2.0 percent were used to make these films. The impact of doped and codoped films on structural, optical properties, and morphological has been examined using a variety of characterization approaches. A ZnO nanocrystal with a diameter of 20-30 nm was discovered using XRD (X-ray diffraction). According to SEM (scanning electron microscope) scans, the grain size is in the 80-120 nm region. The use of Fourier transform infrared spectroscopy (FTIR) to detect elemental elements was studied, and the peak at 400-520 cm-1 was identified as ZnO. The optical properties of doped and codoped ZnO were checked, and it was discovered that antimony-doped ZnO has a larger band gap than Al and antimony-codoped ZnO. This proved that ZnO may be used in gas sensors and solar cells. The gas response of a static gas sensor system based on Sb-doped films was measured and compared to Al- and Sb-codoped films in the presence of ethanol vapor. [ABSTRACT FROM AUTHOR]

The rampant use of cyanide in mining activities has posed a substantial hazard to aquatic ecosystems and human health. Herein, a composite film of poly(vinyl alcohol)/chitosan (PVA/CS) with gold nanoparticles was synthesized as a potential colorimetric sensor for cyanide ions detection in water. The utilized AuNPs with a mean diameter of 14.32±3.49 nm were synthesized by chemical reduction using polyethyleneimine. Ultraviolet-visible spectroscopy revealed the characteristic peak of AuNPs at around 530 nm in the spectrum of PVA/CS/AuNP film, while SEM microscopy revealed the integration AuNPs across the polymer substrate. A color change from red to colorless was observed on the composite film after the addition of water samples with cyanide ions with a visual detection limit between 0.1-1 ppm. The sensor also exhibited good selectivity towards cyanide against the tested water samples containing various metal ions. This study reveals the potential of the fabricated PVA/CS/AuNP composite film as a simple, affordable, and environmentally benign material for on-site detection of cyanide in water and other related application. [ABSTRACT FROM AUTHOR]

The increasing focus on sustainable construction is driving the industry toward materials that combine functionality with environmental benefits. A viable approach to address this demand is the use of bio-based additives to improve traditional cementitious composites. This study introduces a novel approach to developing a polymer-modified construction material by incorporating varied amounts (0, 1, 2, 3, and 6%) of bio-based polyurethane (PU), derived from polyglycerol polyester polyol, into cementitious mortar. The resulting PU-modified cementitious mortar (PUMC) was evaluated for its mechanical, physicochemical, and microstructural properties. Results show that the incorporation of 2% PU by cement weight significantly enhanced compressive strength by 58.2%, flexural strength by 37.0%, and initial flow performance by 20.0% after 28 days, while a 6% PU incorporation provided the best abrasion resistance. These improvements were attributed to a uniform particle and pore size distribution and the formation of a uniform interpenetrating polymer network (IPN), as confirmed by BET-BJH and SEM-EDX analyses. Additionally, FTIR and TGA analyses revealed that the metal-ligand coordination between Ca 2+ ions in the cement mortar and PU ligand groups strengthened the interfacial connectivity through noncovalent bonding, further enhancing the material properties. This research highlights the potential of bio-based PU as an eco-friendly additive that significantly improves the performance of cementitious mortars, making it a promising option for industrial flooring applications., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Semiconducting nanoparticles (SNPs) have garnered significant attention for their role in photocatalysis technology, offering a cost-effective and highly efficient method for breaking down organic dyes. Of particular significance within SNP-based photocatalysis are tunable band gap TiO 2 nanoparticles (NPs), which demonstrate remarkable enhancement in photocatalytic efficiency. In the present work, we introduce an approach for the synthesis of TiO 2 NPs using kappa-carrageenan (κ-carrageenan), not just as a reducing and stabilizing agent but as a dopant for the resulting TiO 2 NPs. During the synthesis of TiO 2 NPs in the presence of sulfate-rich carrageenan, the process predominantly leaves residual sulfur and carbon. The presence of residual carbon, in conjunction with sulfur doping, as indicated by fast FTIR spectra, XPS, and EDX, leads to a significant reduction in the band gap of the resulting composite to 2.71 eV. The reduction of composite band gap yields remarkable degradation of methylene blue (99.97%) and methyl orange (97.84%). This work presents an eco-friendly and highly effective solution for the swift removal of environmentally harmful organic dyes., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

To attain efficient removal of hexavalent chromium (Cr 6+ ) from aqueous solutions, a novel polyurethane foam-activated carbon (PUAC) adsorbent composite was developed. The composite material was synthesized by the binding of coconut shell-based activated carbon (AC) onto a coconut oil-based polyurethane matrix. To thoroughly characterize the physicochemical properties of the newly developed material, various analytical techniques including FTIR spectroscopy, SEM, XRD, BET, and TGA analyses were conducted. The removal efficiency of the PUAC composite in removing Cr 6+ ions from aqueous solutions was evaluated through column experiments with the highest adsorption capacity of 28.41 mg g -1 while taking into account variables such as bed height, flow rate, initial Cr 6+ ion concentration, and pH. Experimental data were fitted using Thomas, Yoon-Nelson, and Adams-Bohart models to predict the column profiles and the results demonstrate high breakthrough and exhaustion time dependence on these variables. Among the obtained R 2 values of the models, a better fit was observed using the Thomas and Yoon-Nelson models, indicating their ability to effectively predict the adsorption of Cr 6+ ions in a fixed bed column. Significantly, the exhausted adsorbent can be conveniently regenerated without any noteworthy loss of adsorption capability. Based on these findings, it can be concluded that this new PUAC composite material holds significant promise as a potent sorbent for wastewater treatment backed by its excellent performance, cost-effectiveness, biodegradability, and outstanding reusability., Competing Interests: The authors declare no conflicts of interest., (This journal is © The Royal Society of Chemistry.)

This study reports light energy harvesting characteristics of bismuth ferrite (BiFeO 3 ) and BiFO 3 doped with rare-earth metals such as neodymium (Nd), praseodymium (Pr), and gadolinium (Gd) dye solutions that were prepared by using the co-precipitation method. The structural, morphological, and optical properties of synthesized materials were studied, confirming that 5-50 nm sized synthesized particles have a well-developed and non-uniform grain size due to their amorphous nature. Moreover, the peaks of photoelectron emission for bare and doped BiFeO 3 were observed in the visible region at around 490 nm, while the emission intensity of bare BiFeO 3 was noticed to be lower than that of doped materials. Photoanodes were prepared with the paste of the synthesized sample and then assembled to make a solar cell. The natural and synthetic dye solutions of Mentha, Actinidia deliciosa, and green malachite, respectively, were prepared in which the photoanodes were immersed to analyze the photoconversion efficiency of the assembled dye-synthesized solar cells. The power conversion efficiency of fabricated DSSCs, which was confirmed from the I-V curve, is in the range from 0.84 to 2.15%. This study confirms that mint (Mentha) dye and Nd-doped BiFeO 3 materials were found to be the most efficient sensitizer and photoanode materials among all the sensitizers and photoanodes tested., (© 2023. The Author(s).)

The optoelectronic properties of the ternary Cd 0.25 Zn 0.75 Se alloy are reported under the influence of a high pressure ranging from 0 to 25 GPa, within a modified Becke-Jhonson potential using density functional theory. This alloy has a cubic symmetry, is mechanically stable, and its bulk modulus rises with pressure. It is observed to be a direct bandgap material with a bandgap energy that increases from 2.37 to 3.11 eV with rise in pressure. Pressure changes the optical and electronic properties, causing the absorption coefficient to rise and absorb visible green-to-violet light. The static dielectric constant, along with the static index of refraction, both increase under the influence of pressure. Optical constants, including dielectric constant, optical conductivity, refractive index, extinction coefficient, and reflection, are also investigated and discussed. This DFT forecast explores important research directions for the usage of the CdZnSe semiconductor alloys in the manufacturing of space photovoltaic and optoelectronic devices operating at different pressures., (© 2022. The Author(s).)