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The present work aimed to account for the first time green, and eco-friendly synthesis of Fe3O4/Cu nanocomposite as magneto-recyclable photocatalyst using Rosmarinus officinalis leaves aqueous extract. R. officinalis leaves extract played three significant roles in improving physicochemical properties of Fe3O4 nanoparticles as reducing, stabilizing and capping agents and can convert Cu2+ ions into Cu0. Several characterization techniques were employed to investigate the crystal structure, surface chemistry, morphology, and optical properties of the produced nanomaterials. The UV–Vis DRS spectra exhibited a low band-gap (1.7 eV), appropriate for an effective visible-light degradation. Effectiveness of Fe3O4 nanoparticles and Fe3O4/Cu nanocomposite as photocatalysts were examined under visible light illumination on an aqueous contaminant solution. Degradation efficiencies of methyl orange, imipenem, and imatinib mesylate, three types of organic contaminations were about 50–96% after 5400 s irradiation over Fe3O4 nanoparticles and Fe3O4/Cu nanocomposite. Total organic carbon analysis results confirmed degradation efficiencies of all samples. Trapping experiments results verified that O2− was the main oxidative species in the degradation of organic contaminations. The as-prepared photocatalysts could be reused after five successive cycles with no significant reduction in degradation efficiency. Besides, biogenic nanoparticles and nanocomposite were promoted H2O2 production. The photochemical production of H2O2 was achieved under visible light irradiation toward the two-electron oxygen reduction reaction. The plausible mechanisms for photocatalytic and degradations were proposed, which suggested the prepared photocatalysts' remarkable potential for removing contaminants with complex structures.

This work reports the synthesis and application of uniform and spherical molecularly imprinted polymeric (MIP) nanobeads for selective and efficient preconcentration of Rosmarinic acid (RA). The as-prepared RA MIP nanobeads were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Brunauer–Emmett–Teller (BET) techniques. As analyzed, nano-sized particles of MIP with spherical and uniform shape and the average size of 88 nm were synthesized. The prepared MIP nanobeads were used in an ultrasonic-assisted dispersive solid phase extraction approach (UA-DSPE) for extraction of RA as a natural antioxidant specie from the extract of Salvia Officinalis leaves. In UA-DSPE process, the RA content of the samples was determined using high-performance liquid chromatography (HPLC). The highest recovery percentage (>90%) was observed after loading of RA solution (pH 5.7) and after elution with 3 mL of acetic acid aqueous solution, followed by 6 min sonication. The selectivity studies demonstrated a selective and high affinity binding of the template molecule (i.e. RA) toward MIP sorbent compared to other compounds such as gallic acid, caffeic acid, and pyrocatechol.

In this work, a green and plant-mediated approach based on the aqueous extract of the Ficus Johannis plant was presented for synthesis of zinc sulfide (ZnS), as efficient and eco-friendly nanophotocatalysts (NPCs). In the first phase, after identification, collection, and drying of the plant, the aqueous extract of the plant fruits was prepared by microwave-assisted extraction (MAE) technique. The characterization of the as-prepared ZnS NPCs was carried out by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution scanning electron microscopy (HR-SEM), Fourier-transform infrared spectroscopy (FT-IR), fluorescence, and UV–Vis absorption spectroscopy. The fluorescence and UV–Vis absorption investigations showed an obvious emission peak between 420 and 440 nm with a broad absorption band between 290 and 320 nm. From SEM and TEM images, the particle size of the ZnS NPCs was estimated to be smaller than 20 nm. In the next step, the application of the as-prepared ZnS NPCs was examined as for photodegradation of some industrial pollutants including naphthalene (Naph), anthracene (AnT), 4- chlorophenol (4-CP), and 4- nitrophenol (4-NP). The effect of experimental parameters on photodegradation percentage of the pollutants such as NPCs dosage, initial pollutant concentration, UV-irradiation time, scavenger type was studied. Under optimum conditions, high-degradation efficiency was obtained using a low amount of ZnS NPCs, after 120 min UV irradiation. Finally, the probable mechanism of the presented heterogeneous photodegradation approach was discussed, too.

Here, calcium tungstate nanoparticles (CWONPs) were synthesized by the hydrothermal method. The reaction parameters including calcium salt concentration, surfactant concentration, reaction time and temperature have been optimized by Taguchi Design Method for smaller particles size. The morphology, size, crystallinity and chemical structure of nanoparticles were investigated by different methods. The optimized calcium tungstate nanoparticles (opt-CWONPs) with average size of 51 nm were showed outstanding removal effectiveness for three different pollutants including methyl orange, imipenem and imatinib mesylate over UV illumination. Nearly, 100% of methyl orange, 98% of imipenem and 60% of imatinib mesylate are degraded at 1800s over opt-CWONPs with banggap 3.7 eV. In addition, a modified carbon paste electrode was formed with opt-CWONPs and linear sweep voltammetry was used to analyze its electrocatalytical activity in acidic media. The findings showed that the carbon paste electrode modified by opt-CWONPs had a higher current density in the hydrogen evolution reaction (HER) than the bare carbon paste electrode. This article has subsequently revealed a revolutionary method for opt-CWONPs preparation and demonstrated its multifunctionality as photocatalyst and electrocatalyst active ingredients.

The present study reported a green approach for sonochemical-assisted synthesis (SAS) of cadmium selenide nanoparticles (CdSe NPs) by using the aqueous extract of Leontice Leontopetalum plant. The aqueous extract was obtained by ultrasonic- assisted extraction (UAE; 15 min, 50°C) and microwave- assisted extraction (MAE; 15 min, 180, and 270 W) as two instrumental techniques. Next, the as-prepared aqueous extracts were used in a plant-mediated synthetic approach for the synthesis of CdSe NPs by applying the SAS technique. The synthesized samples were characterized via different techniques; including transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), ultraviolet-visible absorption; photoluminescence, and Fourier transform infrared spectroscopy. The average particle size of the prepared CdSe NPs was estimated below 50 nm. UV-Vis absorption and fluorescence techniques indicate a wide absorption band around 360–420 nm and an intense emission peak around 460 nm, respectively. After green synthesis and characterization, antimicrobial, antioxidant, and antifungal properties of the aqueous plant extracts as well as their corresponded CdSe NPs were evaluated by different assays, comparatively. Moreover, the genotoxicity and toxicity potential of the samples were investigated. The results indicate the significant antimicrobial activity of the extracts as well as the CdSe NPs, with the negligible toxicity and genotoxicity impacts.

In this study, the effect of three different transition metal ion dopants (Mn

A simple biogenic approach for synthesis of Fe

In this study, a new carbon paste electrode (CPE) modified with porphyrin-based ion imprinted polymer (IIP) was designed and applied for the potentiometric determination of Cu2+ ions in aqueous solutions. The Cu-IIP was prepared using methacrylic acid, ethyleneglycoldimethacrylate monomers, in the presence of a copper complex of 5,10,15,20-tetrakis(4-hydroxyphenyl)-porphyrin. After polymerization, the prepared polymer was eluted by an aqueous solution of hydrochloric acid to leach the imprinted ions, which results in an obvious change in its color from purple to light brown. By microscopic analysis, the mean particle size of the prepared leached IIP was estimated to be around 60 nm. After characterization, the prepared IIP NPs were used as a modifier to design a modified CPE for potentiometric determination of Cu2+ ions in aqueous solutions. As found, at the optimum paste composition, the modified potentiometric sensor exhibited an excellent Nernstian response (30.15 ± 0.2 mV dec−1) to the logarithm of Cu2+ ion concentration over the concentration range of 4.0 × 10−9 to 2.0 × 10−1 mol L−1. Moreover, the designed sensor showed a low detection limit (2.0 × 10−9 mol L−1) with a short response time (∼5 s) and acceptable stability (at least 2 months). In addition, the sensor was successfully applied as a reasonable indicator electrode in potentiometric titration (against EDTA) with high precision and accuracy. Applicability of the IIP NP modified CPE was examined and confirmed by analysis of various water samples for the determination of Cu2+ ions.

This study presents a rapid water-based chemical precipitation method for synthesis of zinc sulfide (ZnS) quantum dots (QDs), under the ultrasonic radiation, using two capping agents; including 2-mercaptoethanol and l-cysteine. It is demonstrated that by applying ultrasonic radiation, the synthesis time can be significantly decreased. The effect of capping agent type on the color specifications (using colorimetry), absorption spectra (using ultraviolet–visible absorption spectroscopy) and ZnS structure (using X-ray diffraction) are investigated. The results of the research indicate that the as-synthesized QDs were cubic structures with dimensions less than 10 nm. After characterization, the QDs samples were performed as nano-scaled photoatalysts, through a UV-driven photodegradation process for the degradation of crystalline violet (CV) as a pollutant dye. Moreover, the present study assesses the effect of operating conditions including the pH of the dye solution, UV-irradiation time, ionic strength, type and dosage of nanophotocatalyst on degradation efficiency. Experimental results of the research demonstrate the QDs can be reused for at-least five times, without a significant decrease in their photocatalytic properties. The maximum photodegradation efficiency for the CV solution adjusted at pH 11, in the presence of a low amount of QDs (i.e. 5 mg) was observed after 90 min irradiation time. Finally, the probable mechanism and kinetics of degradation reaction are proposed in the study. From the kinetic data, the acceptable regression coefficient values (>0.98) for the pseudo first-order kinetic model was obtained for expression the present QD-based photodegradation approach.

Environmental pollution has become one of the greatest problems worldwide, and photocatalysts have attracted a great deal of attention as one solution to this problem. In the present study, we report a novel environmentally friendly property of graphene quantum dots (GQDs) as efficient nano-materials for the degradation of organic pollutant dyes based on the photocatalytic behavior of GQDs under visible-light irradiation. GQD samples were derived from citric acid by a pyrolysis procedure. The synthesized GQDs were characterized by various techniques including transmission electron microscopy, UV–Vis absorption, Raman spectroscopy, fluorescence spectroscopy, and zeta potential measurements. The photocatalytic degradation of Celestine Blue (CB) was studied using GQDs under visible light irradiation. The effect of pH value, contacting time, dosage of GQDs, and initial dye concentration on the degradation kinetics of CB was systematically investigated. MS analyses were conducted to determine the degradation products evolving during the photocatalytic degradation. The possible mechanisms of degradation of CB based on GQDs under visible light are discussed as well.

In this work, a new modified carbon paste electrode (CPE) was constructed for potentiometric determination of naproxen (NAP) based on its imprinted polymer as a chemical modifier. An efficient precipitation polymerization method was applied for the synthesis of nano-sized NAP molecular imprinted polymer (MIP). In the preparation of MIP, methacrylic acid and ethylene glycol dimethacrylate were used as the functional monomer and cross-linking agent, respectively. The nano-sized NAP-MIP was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy (SEM). SEM images confirmed the nanostructure morphology of the prepared MIP, with a particle size range of 50–80 nm. The MIP based sensor with the optimum composition exhibits a good linear response with a slope of −59.5 ± 1.5 mV per decade over the concentration range of 1.0 × 10−9.5–1.0 × 10−1 mol L−1. It has a very low limit of detection, 3.0 × 10−10 mol L−1, with a response time of 3 s. The potentiometric response of the sensor was independent of the pH of test solution in a wide range of 5.0–11.0. The proposed electrode shows a very good selectivity for NAP over other drugs. The chemically modified CPE indicated an excellent applicability for the determination of NAP in NAP capsules.

In this work, a simple, efficient and powerful photocatalytic methodology based on application of pure zinc sulfide (ZnS) quantum dots (QDs) is presented for the removal of naphthalene, as a model molecule of industrial pollutants. A facile room-temperature precipitation method was applied for the synthesis of ZnS QDs, in the presence of 2-mercaptoethanol as capping agents. The characterization of the prepared QDs was carried out by X-ray diffraction (XRD), transmission electron microscopy, high-resolution scanning electron microscopy, scanning tunneling microscopy, fluorescence, and UV–Vis absorption spectroscopies. The XRD investigations indicated that the prepared ZnS QDs are crystalline, with cubic zinc blend structure, with the average particle diameters of 1.2 nm. The fluorescence and UV–Vis absorption investigations showed a narrow and sharp emission band at 424 nm with a broad adsorption band around 235 nm. In addition, the prepared ZnS QDs were used as nanophotocatalysts, for the removal of naphthalene, as a model molecule. The influence of the experimental parameters on the removal efficiency of the ZnS QDs was studied. According to the results, the highest photocatalytic degradation of naphthalene in the presence of ZnS QDs (>95 %) was obtained at alkaline pH, in the presence of 10 mg of QDs, after a reasonable reaction time.

A simple biogenic approach for synthesis of Fe3O4/Au nanocomposite with 31 nm size using aqueous extract of Carum carvi L. seeds has been reported. Phytochemicals of Carum carvi L. seeds extract play three roles, including reducing, capping, and stabilizing agents during the nanocomposite fabrication process. Resulting nanocomposite was characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, differential reflectance spectroscopy, vibrating-sample magnetometer, energy-dispersive X-ray spectroscopy and X-ray elemental mapping. Differential reflectance spectroscopy investigated optical property and absorption spectra display a sharp absorption agreeing to a bandgap of 1.6 eV. Photocatalytic activity of biogenic Fe3O4/Au nanocomposite has been investigated for degradation of imatinib and imipenem drugs under UV and visible light irradiation, due to pharmaceuticals have shown to be recalcitrant in wastewater and conventional wastewater treatments do not remove them, often. Degradation efficiency of imatinib, and imipenem are about 92% and 96% after 1200 s exposure UV light and about 82% and 84% after 3600s exposure visible light in the concentration of 10 ppm drugs. Also, antimicrobial activity of biogenic Fe3O4/Au nanocomposite was investigated on three human pathogens and best result can see in 25 mg/mL of nanocomposite versuse Bacillus subtilis that inhibition zone is about 27 mm. Design of nanocomposites capable of simultaneously removing pharmaceutical and microbial contaminations is important in environments such as hospitals wastewater treatment.

In the present research, two magnetic nanophotocatalysts (MNPCs) including iron oxide nanoparticles decorated with zinc sulfide quantum dots (Fe3O4@ZnS QDs), and N,S- doped graphene QDs (Fe3O4 @ N, S-GQDs) were synthesized by the sonochemical and hydrothermal methods, respectively. The prepared MNPCs were characterized by various techniques including X-Ray Diffraction (XRD), field emission scanning electron microscopy (FE-SEM), vibrating sample magnetometer (VSM), UV–vis absorption and Fourier transform infrared (FT-IR) spectroscopy. The SEM images show the formation of nano- sized particles of Fe3O4, also the morphology and size of the particles were changed after their decoration with ZnS and GQDs. The magnetic saturation values of Fe3O4@ZnS QDs and Fe3O4 @ N, S-GQDs samples were obtained as 19.43 and 55.58 emu.g−1, respectively. The desirable paramagnetic properties of the samples provide suitable magnetic separation process and simple recyclyig of MNPCs. The photocatalytic activity of the as-synthesized samples was evaluated through investigating their ability to degrade an organic pollutant (i.e. Victoria Blue R dye) in aqueous media. The photodegradation efficiency was evaluated based on the decrease of VBR concentration at its maximum absorption wavelength, in the presence of Fe3O4@ZnS QDs and Fe3O4 @ N, S-GQDs as nanophotocatalyst and under ultraviolet (UV) and visible (Vis) light irradiations, respectively. In optimization experiments, the effect of various factors including pH, dye concentration, irradiation time, MNPC dosage, type and concentration of salts were investigated. The maximum photodegradation percentage of Fe3O4@ZnS QDs was obtained as 93.44 % at pH 8, and in the case of Fe3O4 @ N, S-GQDs as 96.68 % at pH 9, after 120 min irradiation.

Here, a selective nano-sized magnetic sorbent based on iron oxide (Fe3O4) core and molecular imprinted polymer (MIP) shell was synthesized and used as a selective sorbent for separation of piroxicam (PIX) from aqueous media. The magnetic MIP functionalized with NH2 group (Fe3O4@SiO2@NH2) was prepared by a surface imprinting approach. The characterization of the MMIP sorbent was carried out by scanning electron microscopy (SEM), infrared spectroscopy (FT-IR), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), Brumauer-Emmett-Teller (BET) and Barrett–Joyner–Halenda (BJH) analyses. The results indicated that the magnetic sorbent were as microspherical nanoparticles with the average size of 50 nm, with well water-dispersibility and easily magnetically separation. The influence of the variables on PIX recovery including initial pH of sample solution, volume and concentration of the eluent, ultrasonic time, ionic strength, and the amount of MMIP were studied and optimized. The linear range (LR), relative standard deviation (RSD) and limit of detection (LOD = 3Sb/m) for determination of PIX were found to be 0.01–10.0 mg L−1, 2.56 % and 5.0 ng mL−1, respectively. The used Fe3O4@SiO2@NH2-MMIP sorbent can be regenerated with 2 ml of pure methanol, without any significant decrease in its adsorption affinity. The results demonstrated an enhanced affinity for the as-prepared MMIP toward the PIX compared to non-imprinted polymer.

Herein, we describe an electrochemical, economically viable, rapid, and optimized procedure to synthesize of sphere Al2W3O12 nanoparticles of 40 nm mean particle size. By using various techniques, size, morphology, chemical structure, and crystallinity were depicted. Considerably, the Al2W3O12 nanoparticles under UV light showed admirable elimination effectiveness for the reduction of three impurities included methyl orange as dye, imatinib mesylate as an anticancer drug with endocrine and mutagenic disruptive effects and imipenem as an antibiotic drug, and the probable mechanism is also suggested. Nearly 90% of methyl orange, 56% of imatinib mesylate, and 75% of imipenem are eradicated in 5000 s, the 1500s, and 1200s on the synthesized nanoparticles. Additionally, the nanoparticles displayed antimicrobial action versus Bacillus, Escherichia coli, and Staphylococcus aureus in the presence of 6.25, 12.5, and 25 mg/ml concentration of nanoparticles. On the other hand, the carbon paste electrode modified with Al2W3O12 nanoparticles was prepared, and its electrocatalytic activity was investigated in an acidic medium for hydrogen evolution reaction by linear sweep voltammetry method. The modified carbon paste electrode has a higher current density and lowers negative potential in the hydrogen evolution reaction compared to the unmodified electrode; the results of linear sweep voltammetry showed. Hence, this article has revealed an innovatory way for preparation Al2W3O12 nanoparticles and represented their multifunctional ability as the photocatalyst, antimicrobial agent and electrocatalytic activity.

In this paper, we have introduced a novel property of graphene quantum dots (GQDs) as efficient nano-materials for degradation of organic pollutant dyes based on the photocatalytic behavior of GQDs under visible light irradiation. GQD samples were synthesized directly through pyrolyzing citric acid method. The synthesized GQDs were characterized by various techniques including colorimetry, transmission electron microscopy (TEM), and UV–vis absorption, Raman spectroscopy, fluorescence spectroscopy, and zeta potential measurements. In this study, a cationic dye (i.e., New Fuchsin) was chosen as a model molecule to investigate catalytic behavior of the prepared GQDs as green nanomaterials. The influence of experimental parameters such as pH of the dye solution, contacting time, dosage of GQDs, and initial concentration of NF dye on the degradation efficiency of GQD were studied. The possible mechanisms of degradation of NF based on GQDs under visible light were discussed, too.

In this research, green and aqueous based synthesis routes were performed for chemical preparation of pure and transition metal ions doped ZnS quantum dots at room temperature. Doping of ZnS QDs by three transition metal ions (Mn2+, Co2+, Ni2+ ions) as dopants have been investigated by various techniques. In the optical absorption studies, a broad absorption band in the wavelength range of 280–300 nm clearly reveals quantum size effect in ZnS QDs. The crystal structure and the approximate size of QDs were measured by XRD pattern. The average particle size of QDs was found to be around 1–3 nm. In addition, the photocatalytic activities of the prepared ZnS QDs as their abilities to remove methyl violet (MV) cationic dye, as a model molecule, were studied. Effect of the experimental parameters, such as the type of dopant and the amount of QDs, pH of the initial dye solution, irradiation time, ionic strength of reaction media, and initial dye concentration on the decolorization efficiency (DE) of QDs as green nano-semiconductors were studied. The results demonstrated that doped QDS (for 5% of dopants) effectively bleached out MV, showing positive photocatalytic enhancement over pure ZnS nanoparticles.

An ion imprinted membrane with a porous polyvinylidene fluoride (PVDF) support was prepared by surface ionic imprinting technology. Ion imprinted membranes possess artificial recognition sites, which are able to specifically rebind a target ion in the presence of other similar compounds. In this study, Ni(II) ion imprinted membrane (IIM) was synthesized by copolymerization of Ni(II) ion (or without it for non-imprinted membrane) and dithizone as chelating ligand in the presence of methacrylic acid (MAA), ethyleneglycol dimethacrylate (EGDMA) as monomer and cross-linker, respectively using 2,2-azobisisobutyronitrile (AIBN) as initiator. Dithizone was selected as complex agent to show the capability of using a non-special ligand for synthesis of selective ion imprinted membrane. The affecting parameter such as pH and concentration of Ni2+ ion solution on the loading capacity of membrane were investigated. To obtain the maximum adsorption efficiency of Ni, pH of the sample solution should be carefully adjusted at 8. In addition, the effect of imprinting technique on the selective recognition of Ni(II) ion towards Co(II) ions through the modified imprinted membrane was studied in the permeation experiments. The results of permeation and adsorption experiment indicated that, the Ni(II) ion imprinted membrane has the ability of specificity and recognition towards the imprinted nickel ion compared to the non-imprinted polymer membrane. The separation factor (α) of the imprinted membrane for the Ni2+ ion versus Co2+ ions was 2.6, whereas the non-imprinted and control membrane (without dithizone ligand) did not show any selectivity.