•Ligand based functional composite material was fabricated for Pb(II) capturing.•The Pb(II) ion detected in optical visualization from the sufficient color formation.•The Pb(II) detection limit was ...low and the maximum adsorption capacity was high.
Detection and removal of toxic metal ions from aqueous solutions is considered among the most important environmental issues in recent years as these metals are hazardous, carcinogenic, and classified as toxic pollutants. In this study, organic ligand embedded large-pore facile composite material was prepared by the direct anchoring method and then, was characterized in systematic ways for understanding the lead (Pb(II)) detection and removal in naked-eye ability in an aqueous solution was evaluated. The material was exhibited the specific functionality for Pb(II) detection and removal from aqueous media with the addition of trace level of Pb(II) ion. The Pb(II) ion detection limit of the presented method was 0.44 µg/L at optimum conditions. The impact of effective Pb(II) ion removal parameters including solution pH, the initial concentration, contact time and desorption ability was studied. The results demonstrated that the addition composite material have synergistic effect on Pb(II) adsorption capacity. The data of adsorption processes clarified that with increased pH up to 5.50, the Pb(II) adsorption was suitable at pH 5.50. Moreover, the composite material exhibited the large surface area-to-volume ratios and uniformly mesostructures shaped pores that were actively working to selective capturing of Pb(II) ion. The adsorption data were well fitted to the Langmuir model and the maximum adsorption capacity was 176.66 mg/g. The material was capable to uptake the Pb(II) ion even in the presence of a high amount of coexisting metal ions. The adsorbed Pb(II) ion was completely eluted with 0.20 M HCl and simultaneously regenerated into the initial form for the next operation after washing with water without loss in its initial performances. Then the modified composite material enhanced the affinity between Pb(II) and functional surface for improving the selectivity to uses a very promising in purification of wastewater.
Display omitted
Display omitted
•Sustainable composite material was fabricated for sensitive Ni(II) ion remediation.•The materials were exhibited immense sensitivity toward Ni(II) ion at optimum state.•The diverse ...competing ion was not interfered due to the strong affinity at selected pH.
Organic ligand based sustainable composite material was prepared for the detection and removal of nickel (Ni(II)) ion from contaminated water. The ligand was anchored based on the building-block approach. The carrier silica and ligand embedded composite material were characterized systematically. The detection and removal of Ni(II) ion operation was evaluated according to the solution pH, reaction time, detection limit, initial Ni(II) concentration and diverse co-existing metal ions. The detection limit of Ni(II) ion by the proposed composite material was 0.41 μg L−1. The detection and removal of Ni(II) ion was significantly influenced by the solution pH. However, the neutral pH 7.0 was chosen for sensitive and selective detection and removal of Ni(II) ion. The co-existing diverse metal ions were not interfered during the detection and removal of Ni(II) ion because of the high affinity of Ni(II) ion to composite material at the optimum experimental conditions. The Langmuir adsorption isotherm model was selected based on the materials morphology and applied to validate the adsorption isotherms according to the homogeneous ordered frameworks. The adsorption capacity was 199.19 mg g−1 as expected due to the high surface area of material. The adsorbed Ni(II) ion was completely eluted from the composite material with the eluent of 0.50 M HCl and the regenerated material was used in several cycles without deterioration in its initial performances. Therefore, it is expected to that the Facile composite material may hold huge potentials in applications and may be scaled up for commercial applications, including environmental detection and removal of Ni(II) ion.
During the transportation of oil and gas, pipes are exposed to flowing corrosive environment which causes erosion-corrosion. The high degradation rates attributed to this mechanism can create ...increased challenges to project economy and operation where material integrity, accurate erosion-corrosion rate prediction and long term performance are key concerns. Although the problem caused by the interaction of erosion and corrosion is severe, the mechanism of synergy is still not thoroughly understood because of its complexity. This research focuses on understanding the degradation processes of pipeline steels (API X42, API X70 and API X100) in CO2 containing salt water. The application of cyclic erosion-corrosion allowed the individual contribution of erosion and corrosion components of mass loss to be quantified and mechanisms by which erosion affects corrosion and vice-versa to be identified. The present research also compares the erosion-corrosion performance of different API steels.
•Erosion-corrosion mechanisms of API steels.•Relative performance comparison of API X42, API X70 and API X100 steels.•Synergism between erosion and corrosion was investigated.•SEM observation was performed to investigate possible erosion mechanisms.
A novel compact design of an ultralow-cost fully printable slot-loaded dual-polarized chipless radio frequency identication tag is presented with four near- and far-field reading techniques. The tag ...consists of four rectangular metallic patches loaded with multiple slot resonators. Slots with the same polarization for adjacent frequencies are placed alternately into two patches to reduce the mutual coupling between the slots. Then two similar sets are placed in horizontal and vertical polarizations to double the number of bits within the same frequency bandwidth. The tag can be detected using dual-polarized waveguide(s) or dual-polarized antennas. This single-sided compact chipless tag has higher data capacity and lower cost compared with the existing printable chipless tags and can be used in personal ID or credit cards and banknotes and can be directly printed on paper or plastic packets for item-level tagging.
In this study, cost-effective cellulosic biomass based activated wood charcoal was developed from Japanese Sugi tree (Cryptomeria japonica) by concentrated nitric acid modification for adsorption of ...Cs from contaminated water. The physicochemical properties of specimens were investigated using N2 adsorption-desorption isotherms (BET method), FESEM, FTIR, and XPS spectra analysis. The experimental results revealed that the surface area of the raw wood charcoal was significantly decreased after boiling nitric acid modification. However, several oxygen-containing acidic function groups (-COOH, –CO) were introduced on the surface. The adsorption study confirmed that the equilibrium contact time was 1 h, the optimum adsorption pH was neutral to alkaline and the suitable adsorbent dose was 1:100 (solid: liquid). The maximum Cs was removed when the concentration of Na and K were lower (5.0 mM) with Cs in solution. The Cs adsorption processes well approved by the Langmuir isotherm and pseudo-second-order kinetic models and the maximum adsorption capacity was 35.46 mgg−1. The Cs adsorption mechanism was clearly described and it was assumed that the adsorption was strongly followed by chemisorptions mechanism based on the adsorbent surface properties, kinetic model and Langmuir isotherm model. Most importantly, about 98% of volume reduction was obtained by burning (500 °C) the Cs adsorbed charcoal, which ensured safe storage and disposal of radioactive waste. Therefore, this study can offer a guideline to produce a functional adsorbent for effective Cs removal and safe radioactive waste disposal.
Display omitted
•A cellulosic biomass based wood charcoal was developed for cesium (Cs) adsorption.•The adsorbent was effective for removal with high sensitivity at optimum conditions.•The adsorption data were well fitted by the pseudo-second order and Langmuir isotherm model.•Volume reduction was ensured the safe storage and disposal of radioactive waste.
Fatty acids (FA) in ruminants, especially unsaturated FA (USFA) have important impact in meat quality, nutritional value, and flavour quality of meat, and on consumer's health. Identification of the ...genetic factors controlling the FA composition and metabolism is pivotal to select sheep that produce higher USFA and lower saturated (SFA) for the benefit of sheep industry and consumers. Therefore, this study was aimed to investigate the transcriptome profiling in the liver tissues collected from sheep with divergent USFA content in longissimus muscle using RNA deep-sequencing. From sheep (n = 100) population, liver tissues with higher (n = 3) and lower (n = 3) USFA content were analysed using Illumina HiSeq 2500. The total number of reads produced for each liver sample were ranged from 21.28 to 28.51 million with a median of 23.90 million. Approximately, 198 genes were differentially regulated with significance level of p-adjusted value <0.05. Among them, 100 genes were up-regulated, and 98 were down-regulated (p<0.01, FC>1.5) in the higher USFA group. A large proportion of key genes involved in FA biosynthesis, adipogenesis, fat deposition, and lipid metabolism were identified, such as APOA5, SLC25A30, GFPT1, LEPR, TGFBR2, FABP7, GSTCD, and CYP17A. Pathway analysis revealed that glycosaminoglycan biosynthesis- keratan sulfate, adipokine signaling, galactose metabolism, endocrine and other factors-regulating calcium metabolism, mineral metabolism, and PPAR signaling pathway were playing important regulatory roles in FA metabolism. Importantly, polymorphism and association analyses showed that mutation in APOA5, CFHR5, TGFBR2 and LEPR genes could be potential markers for the FA composition in sheep. These polymorphisms and transcriptome networks controlling the FA variation could be used as genetic markers for FA composition-related traits improvement. However, functional validation is required to confirm the effect of these SNPs in other sheep population in order to incorporate them in the sheep breeding program.
Nanosheets of silicon have attracted a great deal of attention due to its tunable optical and electronic properties. However, the development of facile and easily scalable synthesis process has ...remained a great contest. Endeavor has been made in this research to find a waste inferred effective photocatalyst to deliver hydrogen (H2) through visible light responsive water splitting.
One-pot solid phase reaction was applied to synthesis catalyst and adopted ultrathin structure. The photocatalytic efficiency of catalyst was examined by XRD, XPS, and UV–VIS absorption spectra, PL, FESEM, HRTEM and EDX. The HRTEM and FESEM images revealed the interconnected nanosheets with Si having the average thickness of 5 nm and their band gaps were 2.3–2.5 eV corresponding to the absorption of visible light range. The H2 production rate on photocatalyst was originated to 3200 μmol h−1 without utilizing any conciliatory electron givers, voltage or pH alteration, which beats the Pt, Ru, Rh, Pd and Au stacked photocatalyst ever detailed up until this point. The significant increase in photocatalytic activity could be the fast charge migration and separation from the silicon-hydrogen and silicon-hydroxyl bonds on Si surface and facilitation of charge separation could results from the multiple reflections of visible light on ultrathin nanosheets. It has been confirmed that the electron/hole recombination rate in ultrathin nanosheets of Si declined due to the oxidation of Si surface. It would be presumed that the approach of surface chemistry of silicon could not be limited towards the photocatalytic water splitting and could be applicable to remedy water pollution.
Display omitted
•Ultrathin nanostructured noble metal free Si/MgO photocatalyst was reported.•Visible light responsive Si/MgO was prepared via one step solid phase reaction method.•XPX showed that the formation of Si-H and Si-OH bonds of Si facilitated the H2 production.•The highest H2 production was found to 3200 μmol h−1g−1 without being affected by any reagent.
As graphene penetrates into industries, it is essential to mass produce high quality graphene sheets. New discoveries face formidable challenges in the marketplace due to the lack of proficient ...protocols to produce graphene on a commercial scale while maintaining its quality. Here, we present a conspicuous protocol for ultrafast exfoliation of graphite into high quality graphene on the sub-kilogram scale without the use of any intercalants, chemicals, or solvent. We show that graphite can be exfoliated using a plasma spray technique with high single-layer selectivity (∼85%) at a very high production rate (48 g/h). This is possible because of the inherent characteristics of the protocol which provides sudden thermal shock followed by two-stage shear. The exfoliated graphene shows almost no basal defect (I d/I g: 0) and possesses high quality (C/O ratio: 21.2, sp2 %: ∼95%), an indication of negligible structural deterioration. The results were reproducible indicating the adeptness of the protocol. We provided several proofs-of-concept of plasma spray exfoliated graphene to demonstrate its utility in applications such as mechanical reinforcements; frictionless, transparent conductive coatings; and energy storage devices.
Azobenzene‐based protonated N‐heterocyclic carbenes (NHCs), N,N’‐bis(azobenzene)imidazolium chlorides (IAz‐X⋅HCl; X=OMe, Br, H) were successfully synthesized and switching abilities of the attached ...azobenzene units along with the concomitant photoinduced generation of geometric isomers were studied. Upon irradiation with 365 nm UV light, a p‐methoxy‐azobenzene derivative get transformed from all‐trans isomer to nearly all‐cis isomer at the photostationary state. The extent of photomodulation of electronic properties in the NHC ring of the p‐methoxy‐azobenzene derivative is determined through the Tolman Electronic Parameter (TEP). Iridium complex, (IAz‐OMe)IrCl(CO)2 was synthesized and infrared spectra were recorded in dichloromethane solution as film in NaCl crystals and by drop‐casting in an ATR crystal. Comparison in averaged carbonyl stretching frequency between all‐trans isomer (ν˜
ttav
) and all‐cis isomer (ν˜
ccav
) indicates a significant decrement of Δtt–ccν˜
av=2.7 cm−1 (film) and 3.8 cm−1 (ATR). Therefore, moderate to excellent enhancement of electron density (Δtt–cc TEP=2.3 cm−1 film and 3.2 cm−1 ATR) at the C‐2 position of the NHC is achieved through trans→cis isomerization of the remotely placed azobenzene units. This fine phototuning of electron‐donating ability at the catalytic center would pave the way to control NHC/NHC‐metal catalyzed organic transformations through external stimuli.
Photoswitches: The photoinduced trans→cis isomerization can alter the electron‐donating abilities of azobenzene‐based N‐heterocyclic carbene. Appropriate iridium‐complex (see Figure) was synthesized and utilized to calculate Tolman Electronic Parameter (TEP) to provide the extent of alteration.
A convenient and efficient solvent-free, facile, one-pot three-component graphene oxide catalysed approach has been described for the synthesis of chromeno-4,3-bquinolin-6-one derivatives from ...4-hydroxycoumarin with aldehydes and aromatic amines. Graphene oxide (GO) has proved to be a new class of heterogeneous carbocatalyst which could be easily recovered and reused up to 5th run without significant loss of its catalytic activity. A broad scope of substrate applicability is offered and a plausible mechanism is also suggested for this developed protocol.
PDF
