OH Functional Groups Research Articles

Coffee charcoal as a green catalyst for oxidative dehydrogenation

Nitrogen heterocyclic (N-heterocyclic) compounds are extensively present in natural products and active drug molecules. However, their synthesis typically requires the use of noble metal catalysts and harsh conditions. In this study, we report a novel approach using coffee charcoal as a green catalyst for the mildly mechanically driven oxidative dehydrogenation of N-heterocyclic compounds. A one-step strategy was employed to construct a microporous coffee charcoal catalyst with C defects, in-situ co-doping of multi-atoms (N, O), and abundant modification of functional groups (–OH and –COOH). Under room temperature and with H2O as solvent, the coffee charcoal catalyst demonstrates a high yield of approximately 94 % and allows for gram-scale reactions with H2O being the only by-product. Moreover, the catalyst exhibits excellent reusability, maintaining its activity for over 13 cycles. Results indicate that the defects and atom doping can enhance the adsorption of O2, which is then activated to singlet oxygen (1O2) through the conversion of –OH functional groups on the catalyst’s surface. The singlet oxygen (1O2) can strengthen the oxidative dehydrogenation of N-heterocyclic compounds. Furthermore, the mechanically driven technique both activates the reaction interface and supplies the necessary reactive energy, thus providing a comprehensive explanation for the mild reaction conditions observed. In conclusion, our research proposes a sustainable and environmentally friendly method for the oxidative dehydrogenation of N-heterocyclic compounds, which can drive crucial reactions with significant relevance to sustainability.

Above-Room-Temperature Strong Ferromagnetism in 2D MnB Nanosheet.

Two-dimensional (2D) room-temperature (RT) ferromagnetic materials have amassed considerable interest in the field of fundamental physics for applications in next-generation spintronic devices owing to their physical properties. However, realizing strong RT ferromagnetism and a high Curie temperature (TC) in these 2D magnetic materials remains challenging. Herein, we develop a 2D MnB nanosheet for known 2D ferromagnets that demonstrates strong RT ferromagnetism and a record-high above-RT TC of ∼585.9 K. Through magnetic force microscopy, clear evidence of ferromagnetic behavior is observed at room temperature. Structural characterization and density functional theory calculations further reveal that (i) after exfoliation of bulk, -OH functional groups were introduced in addition to Mn-B bonds being formed, which increases MnB nanosheet TC to 585.9 K and (ii) the d3↑ spin configuration of Mn mainly contributed to the magnetic moment of MnB, and the hybridization between the dxz (dyz) and dz2 orbitals of the Mn atom provides a large contribution to magnetic anisotropy, which stabilizes the magnetic property of MnB. Our findings establish a strong experimental foundation for 2D MnB nanosheets as ideal materials for the construction of spintronic devices.

The mechanism of silica and transparent exopolymer particles (TEP) on reverse osmosis membranes fouling

Dissolved silica and transparent exopolymer particles (TEP) are the primary foulants in reverse osmosis (RO) desalinated brackish water and wastewater. In this study, we investigated the fouling properties of varying silica concentrations with TEP on the membrane surface and discovered a synergistic fouling effect between the silanol group (Si–OH) and the TEP carboxyl group (-COOH). The membrane fouling experiments showed that silica fouling approached saturation at 6 mM, with little variation in membrane flux as the silica concentration increased. Furthermore, the –OH functional group of the monosilicate molecule can chemically react with the -COO- functional group on the membrane surface to create hydrogen bonds, allowing monosilicate deposition directly on the membrane. Silica-silica interactions reacted with aggregates at high silica concentrations and joined with TEP to create a more substantial, more complex cross-linked network, resulting in severe membrane fouling. At pH 9, silica fouling was most severe due to the dramatic increase in the solubility of monosilicic acid dissolution in solution and the decreased polymerization rate. This work reveals the essential process of membrane fouling induced by silica and TEP, significantly increasing knowledge on silica-TEP fouling.

Ultralow-Overpotential Acidic Oxygen Evolution Reaction Over Bismuth Telluride-Carbon Nanotube Heterostructure with Organic Framework.

The state-of-the-art iridium and ruthenium oxides-based materials are best known for high efficiency and stability in acidic oxygen evolution reaction (OER). However, the development of economically feasible catalysts for water-splitting technologies is challenging by the requirements of low overpotential, high stability, and resistance of catalysts to dissolution during the acidic oxygen evolution reaction . Herein, an organometallic core-shell heterostructure composed of a carbon nanotube core (CNT) and bismuth telluride (Bi2Te3) shell (denoted as nC-Bi2Te3) is designed and use it as a catalyst for the acidic OER. The proposed catalyst achieves an ultralow overpotential of 160mV at 10mAcm-2 (geometrical), thereby outperforming most of the state-of-the-art precious-metal-based catalysts. The low Tafel slope of 30mVdec-1 and charge transfer resistance (RCT)of 1.5Ω demonstrate its excellent electrocatalytic activity. The morphological and chemical compositions of nC-Bi2Te3 enable the generation of ─OH functional group in the Bi─Te sections formed via a ligand support, which enhances the absorption capacity of H+ ions and increases the intrinsic catalytic activity. The presented insights regarding the material composition-structure relationship can help expand the application scope of high-performance catalysts.

Directional electronic tuning of Ni nanoparticles by interfacial oxygen bridging of support for catalyzing alkaline hydrogen oxidation.

Metallic nickel (Ni) is a promising candidate to substitute Pt-based catalysts for hydrogen oxidation reaction (HOR), but huge challenges still exist in precise modulation of the electronic structure to boost the electrocatalytic performances. Herein, we present the use of single-layer Ti3C2Tx MXene to deliberately tailor the electronic structure of Ni nanoparticles via interfacial oxygen bridges, which affords Ni/Ti3C2Tx electrocatalyst with exceptional performances for HOR in an alkaline medium. Remarkably, it shows a high kinetic current of 16.39 mA cmdisk-2 at the overpotential of 50 mV for HOR [78 and 2.7 times higher than that of metallic Ni and Pt/C (20%), respectively], also with good durability and CO antipoisoning ability (1,000 ppm) that are not available for conventional Pt/C (20%) catalyst. The ultrahigh conductivity of single-layer Ti3C2Tx provides fast transmission of electrons for Ni nanoparticles, of which the uniform and small sizes endow them with high-density active sites. Further, the terminated -O/-OH functional groups on Ti3C2Tx directionally capture electrons from Ni nanoparticles via interfacial Ni-O bridges, leading to obvious electronic polarization. This could enhance the Nids-O2p interaction and weaken Nids-H1s interaction of Ni sites in Ni/Ti3C2Txenabling a suitable H-/OH-binding energy and thus enhancing the HOR activity.

Adsorption of Chromium, Copper, Lead, Selenium, and Zinc ions into ecofriendly synthesized magnetic iron nanoparticles.

The iron nanoparticles (Fe-NPs) have been synthesized using an environmentally friendly and simple green synthesis method. This study aims to obtain an aqueous extract from natural material wastes for synthesizing Fe-NPs. The produced Fe-NPs were evaluated as adsorbents for removing Pb, Se, Cu, Zn, and Cr from aqueous solutions. The formation of Fe-NPs was observed on exposure of the aqueous extract to the ferrous chloride and ferric chloride solutions. The characterization of the synthesized Fe-NPs was carried out using different instrumental techniques. As a function of the initial metal ion concentration, contact time, and various doses, the removal of the heavy metal ions was investigated. The UV-Vis spectrum of Fe-NPs showed a peak at 386 nm, 386 nm, 400 nm, 420 nm, 210 nm, 215 nm, and 272 nm of banana, pomegranate, opuntia, orange, potato, and onion, respectively. The FT-IR spectra confirmed the attachment of bioactive molecules from plants on the Fe-NPs surface. The effective reduction of metal ions was greatly aided by the -OH functional groups. The functional groups were examined and responsible for adsorption process by nanoparticle powder sample, these peaks are 3400 cm-1, 2900 cm-1, 1600 cm-1,1000 cm-1, and 1550 cm-1. The magnetization measurements revealed superparamagnetic behavior in the produced iron oxide nanoparticles. Heavy metal ions uptake followed a time, dose, and initial concentration-dependent profile, with maximum removal efficiency at 45 min, 0.4 g, and 3.0 mg/L of metal concentration, respectively.

Self-Polarized P(VDF-TrFE)/Carbon Black Composite Piezoelectric Thin Film.

Self-polarized energy harvesting materials have seen increasing research interest in recent years owing to their simple fabrication method and versatile application potential. In this study, we systematically investigated self-polarized P(VDF-TrFE)/carbon black (CB) composite thin films synthesized on flexible substrates, with the CB content varying from 0 to 0.6 wt.% in P(VDF-TrFE). The presence of -OH functional groups on carbon black significantly enhances its crystallinity, dipolar orientation, and piezoelectric performance. Multiple characterization techniques were used to investigate the crystalline quality, chemical structure, and morphology of the composite P(VDF-TrFE)/CB films, which indicated no significant changes in these parameters. However, some increase in surface roughness was observed when the CB content increased. With the application of an external force, the piezoelectrically generated voltage was found to systematically increase with higher CB content, reaching a maximum value at 0.6 wt.%, after which the sample exhibited low resistance. The piezoelectric voltage produced by the unpoled 0.6 wt.% CB composite film significantly exceeded the unpoled pure P(VDF-TrFE) film when subjected to the same applied strain. Furthermore, it exhibited exceptional stability in the piezoelectric voltage over time, exceeding the output voltage of the poled pure P(VDF-TrFE) film. Notably, P(VDF_TrFE)/CB composite-based devices can be used in energy harvesting and piezoelectric strain sensing to monitor human motions, which has the potential to positively impact the field of smart wearable devices.

Eco-Friendly of Sound-Absorbing Material Based on Polyurethane-Urea with Natural Fiber Waste

Noise has a wide impact on human health and non-health. One of the sound-absorbing materials commonly used in the community is polyurethane-urea foam. However, public concerns about the environment because the availability of petroleum as a raw material for polyurethane-urea foam synthesis is limited, and the waste pollutes the environment, posing a new challenge to be researched. For this reason, this study aims to develop polyurethane-urea foam with a mixture of natural fiber waste as an eco-friendly alternative to sound-absorbing materials. The raw materials used were natural fiber waste (rice straw waste and plywood industry sawdust waste) and chemicals (PEG, MDI, EDA, MAH), with a waste composition of 5% (w/w). The synthesis method employed was a one-shot method. The synthesized foam was characterized by FTIR, camera microscope, SEM, TGA and acoustic tests. The results uncovered that the sample had peaks in the absorption of the functional groups NH, OH, Urethane, Aromatic, and Amide. The morphological structure of the foam consisted of an open cell and a closed cell. Its thermal resistance was above 125°C. In addition, the foam with the highest sound-absorbing ability was polyurethane-urea foam/rice straw waste at 0.83 at a frequency of 4312 Hz.

Adsorption of levofloxacin hydrochloride by microplastics with or without oxygen functional groups

Functional groups can alter the properties of microplastics (MPs), thereby affecting their adsorption of antibiotics.This study selected oxygen free plastics polyvinyl chloride (PVC), polystyrene (PS), and oxygen containing plastics polyethylene terephthalate (PET) as representative MPs to investigate the adsorption behavior of MPs on levofloxacin hydrochloride (LEV) before and after ultraviolet (UV) aging.The research results indicated that the adsorption capacity of PET before and after aging was the strongest (from 0.430 to 0.859 mg/g), followed by PVC (from 0.406 to 0.733 mg/g) and PS (from 0.326 to 0.526 mg/g). After aging, PVC and PS generated C = O, and –OH functional groups, and the content of PET -COOR and –OH has increased. As the pH increases from 2 to 12, the saturated adsorption capacity of MPs first increased and then decreased. The adsorption capacities were suppressed with the presence of NaCl. Pb2+ and Cd2+ inhibited adsorption, as the complexation of oxygen-containing functional groups with metals reduced the saturation adsorption. In the mechanism calculation, the contribution of microporous filling was the most, while the contribution of functional groups was small. The increase of oxygen-containing functional groups enhanced the electrostatic interaction and hydrogen bond.

Structural characterisation of bioactive compounds of Gymnosporia senegalensis (Lam.) Loes. using advanced analytical technique like FT-IR, GC-MS and 1H-NMR spectroscopy

The present investigation was carried out to characterise bioactive components from G. senegalensis by using Fourier-transform infra-red (FT-IR) spectroscopy, 1H-nuclear magnetic resonance spectroscopy, and gas chromatography-mass spectrometry (GC-MS). The FTIR analysis confirmed the presence of > CH2, -CH3, C = C-C, C-H, C-F, C = C, -C = N-, C-C = N-, and -OH functional groups. The 1H-NMR spectrum revealed the presence of structures of four bioactive compounds i.e. tetratetracontana derivative, β-carotene, amyrin, and terpineol. GC-MS revealed the presence of different types of high and low molecular weight chemical entities with varying quantities including volatile and essential oil, monoterpenoid, tetraterpenoid, carotenoid, terpenoid, triterpenes, and nortriterpenes. From the results, it could be concluded that G. senegalensis contains various bioactive compounds of biological and pharmacological importance. Overall, this study will provide insight into the characterisation and development of drugs from medicinal plants.

Biomimetic synthesis and use of silver nanoparticles, an innocuous stratagem to combat fungal diseases in plants

In the era of antimicrobial resistance, the creation of novel nanoparticles with resilient antimicrobial activity and the need to progress a comprehensive approach to fight pathogenic fungi is critical. Due to the immense range of variations of Calotropis procera phytochemicals, their versatile functionalization, and the possibility of multivalent binding sites make it preeminent for use in the present research to synthesize antifungal silver nanoparticles (AgNPs). The UV–visible (UV–vis) spectrum of AgNPs displayed the multiple Surface Plasmon Resonance (SPR) peaks with ʎMax 350 nm, 408 nm, 584 nm, 635 nm and 654 nm and sweeping change in spectrum revealed shape anisotropy. The multifunctional moieties of phytochemicals explored with Fourier Transform Infra-Red (FTIR) spectrum showed SO, PO, NH, OH and CO functional groups involved in a redox reaction that served as capping/stabilizing agents for created amphiphilic colloidal AgNPs structures. The X-ray diffraction (XRD) analysis revealed Face Centered Cubic (FCC) shaped Nano-sized silver. The Atomic Force Microscopy (AFM) analysis displayed predominant prism shape AgNPs with different size collections having a mean size of 28.8 nm. The significant in vitro antifungal activity against plant and human pathogenic fungus Scopulariopsis alboflavescens was observed using the disk diffusion method, and it was resolved that biogenic synthesis of AgNPs from plants will be a safe strategy to combat fungal diseases in plants.

Photocatalytic degradation of fluoroquinolone antibiotics using chitosan biopolymer functionalized copper oxide nanoparticles prepared by facile sonochemical method

Photocatalytic degradation is an excellent method for removing pharmaceutical residues due to their simplicity, ecological benignity, high efficiency, and exceptional stability. Herein, we demonstrate the sonochemically synthesised chitosan biopolymer functionalized copper oxide nanoparticles as an efficient photocatalyst for the degradation of fluoroquinolone-based antibiotics. The X-ray diffraction Rietveld refinement revealed the formation of single-phase copper oxide (CuO) with a monoclinic structure. The presence of biopolymer functionalization was corroborated by Fourier Transform Infrared spectroscopy by observing the -NH2 and -OH functional groups. The high-resolution transmission electron microscopic images inferred that Chitosan functionalized copper oxide (C-CuO) particles are nano-sized with a smooth texture and aggregation-free particles. The strong absorbance and the broad photoluminescence emission in the ultraviolet-visible region confirm the suitability of CuO and C-CuO nanoparticles for photocatalytic applications. The catalytic activity was studied against fluoroquinolone-based antibiotics such as ciprofloxacin and norfloxacin under direct sunlight illumination. Interestingly, the C-CuO catalyst demonstrated 71.07 % (@140 min.) and 71.9 % (@60 min.) of degradation for ciprofloxacin and norfloxacin, respectively. The obtained photocatalytic activity of the prepared CuO and C-CuO catalysts was superior to the CuO particles prepared by the coprecipitation method (CC-CuO).

Chemical, structure and thermal characterisation of biowaste fish bone parts for orthopaedic coatings

ABSTRACT Fish bone waste is a valuable source of natural hydroxyapatite (HA). In this study, different sections of Nile tilapia (Oreochromis niloticus); head bone (T-HEB), otolith bone (T-OTB), operculum bone (T-OPB), and spine bone (T-SPB) were considered for potential natural HA biomaterial. The findings show that the T-OTB powder had a lower size particle distribution with 16.99 µm (d0.5) while T-OPB had the highest one with 148.14 µm (d0.5). Irregular particle morphology was observed for T-OPB, T-OTB, and T-SPB except for T-HEB powder, which owns needle-sharped particles. The phase analysis and the presence of the functional groups of OH−, CO3−2, and PO3− 4 belonging to HA confirmed the formation of HA for previous samples. In contrast, the T-OTB powder was mostly composed of CaO fitting with aragonite peaks according to elemental and phase analyses. The thermal analysis revealed that the volatile/organic compounds were removed completely above 622 °C for T-HEB, T-OPB, and T-SPB and the total mass loss of them was less than 2.17%. While this temperature was 864 °C for T-OTB and total mass loss was higher at 44.5%. The Ca/P ratio of T-HEB, T-OPB, and T-SPB powders was found to be 0.49 higher than the stochiometric HA. The findings suggest that T-HEB, T-OPB, and T-SPB powders can be used in the area of orthopaedic coatings.

Alkalization treatment engineering gas sensing selectivity improvement of ZnCo2O4 microspheres toward xylene

Improving the recognition ability of gas sensing materials toward target gases is one of the eternal themes of gas sensor research. Here, a feasible alkalization treatment strategy is proposed and is used to greatly improve gas sensing selectivity and response of oxide semiconductor based sensing materials. To be specific, ZnCo2O4 microspheres could be prepared through a solvothermal strategy with annealing, but do not exhibit gas sensing selectivity. When treated with 0.5 M sodium hydroxide aqueous solution, the alkalized ZnCo2O4 microspheres (ZCO-0.5) show significantly enhanced xylene gas sensing selectivity at 160 °C. Meanwhile, the ZCO-0.5 sensor also exhibits superior stability, repeatability and reliability toward xylene gas. The enhanced selectivity of xylene gas sensing originates from more exposed metal-oxygen bonds, OH functional groups, -O terminal groups and Co3+ ions on the surfaces of ZnCo2O4 microspheres introduced by the alkalization treatment of sodium hydroxide solution with appropriate concentration. The alkalization treatment method in this study could be applied to other oxide semiconductors to enhance their gas sensing selectivity and performances.

The inhibition effect of white dextrin on Al1050 alloy corrosion behavior in the NaOH media: Thermodynamic and kinetic study

In this research, white dextrin as a new, low-cost, and eco-friendly inhibitor was used in 0.05 M NaOH electrolyte for investigating the corrosion behavior of Al1050 alloy. Dextrin contains many OH functional groups to be a proper candidate for adsorbing on the metallic surface. To study this behavior, potentiodynamic polarization (PDP), electrochemical impedance spectroscopy, and weight loss tests were utilized. Furthermore, to evaluate the topography of the surface, atomic force microscopy, and scanning electron microscopy were also used. PDP result tests showed that the highest inhibition efficiency for dextrin was about 97% at ambient temperature in the presence of 1 g/L dextrin. By increasing the test temperature from 298 to 328 K the inhibition efficiency was reduced from 97% to 49% indicating the physical adsorption of dextrin at the metal surface. Results of weight loss tests displayed that the inhibition efficiency decreased up to 40% after 48 h. The surface analysis showed that based on the presence of dextrin, the smoothness of the corroded surface increased about by 64% compared to the uninhibited surface. The obtained results confirmed that the adsorption mechanism of dextrin was obeyed from Langmuir isotherm.

Synthesis of salicylaldehyde tailored PAMAM dendrimers/chitosan for adsorption of aqueous Hg(II): Performance and mechanism

Water pollution caused by Hg(II) exerts hazardous effect to environmental safety and human health. Herein, a family of salicylaldehyde tailored poly(amidoamine) (PAMAM) dendrimers/chitosan composites (G0-S/CTS, G1-S/CTS, and G2-S/CTS) were prepared and used for the removal of Hg(II) from water solution. The adsorption performance of the as-prepared composites for Hg(II) was thoroughly demonstrated by determining various influencing factors. G0-S/CTS, G1-S/CTS and G2-S/CTS exhibited competitive adsorption capacity and good adsorption selective property for Hg(II). The maximum adsorption capacity of G0-S/CTS, G1-S/CTS and G2-S/CTS for Hg(II) were 1.86, 2.18 and 4.47 mmol‧g−1, respectively. The adsorption for Hg(II) could be enhanced by raising initial Hg(II) concentration and temperature. The adsorption process was dominated by film diffusion processes with monolayer adsorption behavior. The functional groups of NH2, CONH, CN, OH, CO and CN were mainly responsible for the adsorption of Hg(II). G0-S/CTS, G1-S/CTS and G2-S/CTS displayed good regeneration property and the regenerate rate maintained 95.00 % after five adsorption-desorption cycles. The as-prepared adsorbents could be potentially used for the efficient removal of Hg(II) from aqueous solution.

Green Synthesis and Biological Study of New Imidazothiazines Using New MCRs: A Combined Experimental and Theoretical Investigation

For the performing this research multicomponent reaction of isatin, electron-deficient acetylenic compounds, α-haloketones, ammonium acetate, isothiocyanates and methyl aziridine in aqueous at room temperature was investigated for the production of novel derivatives of azepinothiazine in excellent yields. The synthesized azepinothiazines have OH, NH2 and NH functional groups that have acidic hydrogen and show high antioxidant activity. These synthesized compounds also displayed antimicrobial activity by using the disk diffusion procedure and two Gram-positive and Gram-negative bacteria. Also, to better understanding reaction mechanism density functional theory-based quantum chemical methods have been applied. The employed process for the production of azepinothiazine has some benefits such as short time of reactions, excellent efficiency of the product, easy separation of products.

Sliding behavior at the graphene oxide and polyethylene interface

Harnessing their excellent physical attributes, two-dimensional nanostructures have gained prominences as reinforcements in polymer nanocomposites. Given the intricate structure of nanofillers and the varied interfacial connections, in-depth understanding of the strengthening mechanisms becomes pivotal for optimizing nanocomposite design. By varying the GO's morphology, a notable divergence of approximately 30% is evident in the interfacial shear strength. This divergence is attributed to the mechanical interlocking effect instigated by the presence of -O- and -OH functional groups. Functionalizing with groups like -CH3-CH2-NH2 (-Ethylamine) and -(HOCH2)3CNH2 (-TRIS) enhances the mass density of PE polymers at the interphase, which changes the interface sliding (low-density interphase) to the cohesive sliding during the pull-out process. As a result, the maximum interfacial shear strength (204–223 MPa) of these two samples is much larger than that of the pristine GO/PE (149–151 MPa), and even comparable with the pure PE's tensile strength. Intriguingly, shorter or highly flexible functional group exhibit a comparatively weaker influence on the interfacial shear strength. Moreover, as the sliding surface shifts toward the cohesive zone, diminishing sample thickness (less than 60 Å) generally corresponds to augmented interfacial shear strength due to the boundary confinement effect. In summary, this work offers a comprehensively elucidation of GO/PE pull-out behavior, facilitating the design of nanocomposites with exceptional mechanical performance.

Polystyrene and low-density polyethylene pellets are less effective in arsenic adsorption than uncontaminated river sediment

The adsorption process of inorganic arsenic (As) plays an important role in its mobility, bioavailability, and toxicity in the river environment. In this work, the adsorption of dissolved arsenite (As(III)) and arsenate (As(V)) by microplastics (MPs) pellets (polystyrene (PS) and low-density polyethylene (LDPE)), river sediment, and their mixture were investigated to assess the adsorption affinities and mechanism. The adsorption kinetics showed slow and mild rising zones from the natural behavior of the chemical adsorption. The results indicated that both MP characteristics and water properties played a significant role in the adsorption behavior of inorganic As species. The As adsorption equilibrium was modeled well by both Langmuir and Freundlich isotherms and partly fitted with the Sips model suggesting that both mono-layer and multi-layer adsorption occurred during adsorption The spontaneous adsorption process for both As(III) and As(V) was evidenced by the adsorption thermodynamics. The maximum adsorption capacities of As(III) and As(V) reached 143.3 mg/kg and 109.8 mg/kg on PS in deionized water, which were higher than those on sediment-PS mixture (119.3 mg/kg, 99.2 mg/kg), which were all lower than on sediment alone (263.3 mg/kg, 398.7 mg/kg). The Fourier transform infrared spectroscopy analysis identified that As(III) and As(V) interaction with sediment surface functional groups was the main adsorption mechanism from surface complexation and coordination. Two functional groups of polystyrene (-NH2, -OH) were mainly involved in the adsorption of inorganic As species on PS, while -COO- and -OH functional groups contributed to the adsorption mechanism of inorganic As species on LDPE. The findings provide valuable insight on the adsorption behavior and mechanisms of As(III) and As(V) in river systems in the presence of MPs particles. Both PS and LDPE were shown to be less effective than river sediment in the adsorption of As species from water, which provides a different perspective in understanding the scale of MPs impact in pollutant transport in the aquatic environment.Graphical

Fabrication of CuNPs Using Schiff Base Ligand and Their Catalytic Reduction of Pharmaceutical Drugs, Fluorescence Selective Detection of Cd2+, Antimicrobial, and Antioxidant Activities.

Here, we have approached the synthesis of copper nanoparticles (CuNPs) Schiff base (5-trifluoromethoxy-2-(((2chloro-5-(methyl)phenyl)imino)methyl)phenol)). The synthesized CuNPs were characterized by UV-vis spectroscopy, PL, FTIR, powder XRD, and TEM analysis. From the UV-vis absorption spectroscopy, an absorption peak was observed at 585 nm. As a result of the powder XRD and TEM studies, spherical particle sizes ranged between 4 and 10 nm. FT-IR analysis confirmed the presence of functional groups ‒OH, C=C, -C=N-, and C‒H triggers the synthesis of CuNPs. Further, the catalytic property of the CuNPs were revealed by the degradation of pharmaceutical drugs such as Capecitabine (CAP) and Ciprofloxacin (CIP) in 90 min of reaction time in the presence of NaBH4. The reaction kinetics followed pseudo-first-order with k-values (rate constant) 0.248 min-1 and 0.307 min-1. In addition, the synthesized CuNPs have exhibited selective sensing detection of Cd2+ metal ions in different range of concentration (10-100 µM) by spectrofluorometrically with the limit of detection (LOD) is 0.0284 nM and limit of quantification (LOQ) is 0.0586 nM. The CuNPs revealed significant antioxidant activities against DPPH as a common free radical at 50 µg/mL with 71.24% of scavenging activity. The maximum antimicrobial potential and zone of inhibition of P. Aeruginosa is 17.25±0.8 mm and A. niger is 12.1 mm by using CuNPs.