In this study, graphene oxide used as a stable support to adsorb and stabilize palladium nanoparticles for preparing a heterogeneous nanocatalyst. In order to increase the palladium adsorption, the surface of graphene oxide was functionalized with β-Cyclodextrin and cyanoguanidine compounds. The prepared nanocatalyst was defined by various characterization techniques such as FT-IR, XRD, TEM, SEM–EDX, ICP and UV–Vis. The catalytic efficiency of the synthesized organic–inorganic nanocomposite investigated by focusing on the Suzuki–Miyaura binding reaction and reduction of 4-nitrophenol to 4-aminophenol, which the nanocatalyst work is easy, affordable, and environmentally safe. The performed reaction showed high yields of biphenyl compounds through the Suzuki–Miyaura reaction and confirms very good conversion of 4-nitrophenol to its reduced form. Also, the proposed nanocatalyst presented significant catalytic efficiency (yield: 98% to 91%) after using five times.
Graphical AbstractWater and microbial contamination is a serious issues to aquatic system and human health. The metal selenide has a tremendous technique to degrade the dyes and bacteria.The present work reports the synthesis of ZnSe nanoparticles in a simple co-precipitation method. The synthesized samples were analyzed by structural, optical, morphological, catalytic and biological activity. The size and bandgap by annealing temperature tuning which are confirm by X-ray Diffraction and UV–Visible spectrometer. The quasi-spherical shapes were confirmed by Scanning Electron Microscope and Transmission Electron Microscope.The photo excited electrons have trapped the metals and promoting the degradation system. The release of ions to the surface was acknowledged by Photo Luminescence spectroscopy. The photocatalytic dye degradation of the Methyl Orange showed that the enhanced activity in high temperature. The photocatalytic dye degradation activity suggested that the temperature change the production of free radicals and ROS formation. The hydroxyl radicals were slewing the dye molecules and bacteria. The obtained results giving the information of ZnSe nanoparticles are one of the fascinating research areas in the current research world. Because of its large application in different field it acts as a promoting catalytic and biological application.
Graphical AbstractGraphene based magnetic nanohybrids have engrossed considerable research curiosity because of their exceptional properties and diverse applications associated with green chemistry. In this regard, a practical, facile and regioselective preparation of 1,2-diamines from N-tosylaziridine/(S)-(+)-2-Benzyl-1-(p-tolylsulfonyl)aziridine and aryl amines in the presence of magnetically separable graphene based nanohybrid (CoFe@rGO) has been proposed under mild and solvent free conditions. The FT-IR, FE-SEM, XPS, XRD and TEM spectroscopic analysis confirmed the formation of the CoFe@rGO nanohybrids. For unsymmetrical aziridine, nucleophilic attack of aryl amines was observed to take place selectively at the more substituted carbon atom of aziridine ring. Environmentally benign, efficient, shorter reaction time, solvent-free conditions, low catalyst loading, excellent reaction yields and reusability of the catalyst for six consecutive runs without significant loss in its activity are the key advantages of this protocol.
Graphical AbstractThis article presents two highly fluorescent donor-π-acceptor (D-π-A) moieties containing an electron-donating carbazole and phenothiazine donors fused with electron-withdrawing pyrrolo-quinoline acceptor dyes, PQC and PQPT. We also discussed the polymerization and film-forming process of dye PQC and PQPT doped in poly (methyl methacrylate) (PMMA) and polystyrene (PS) polymer to find their optical applications in polymer-based technology. We investigated the fluorescent properties of dyes PQC and PQPT from 0.01 to 1 wt% in poly(methyl methacrylate) (PMMA). We also investigated the changes in the spectrum shape and shift in wavelength with changes in poly(methyl methacrylate) (PMMA), polystyrene (PS), and TiO2 doped in polystyrene (PS/TiO2). The analysis of surface morphology of prepared polymer samples was done with the help of a scanning electron microscope. The thermal and photostability of synthesized dyes in poly (methyl methacrylate) (PMMA), polystyrene (PS), and TiO2 doped in polystyrene (PS/TiO2) were investigated to get detailed information owing to the application of fluorescent polymers in the field of optoelectronic, nanohybrid coatings in solar concentrators, etc.
Graphical AbstractThe metal centres of nano-zeolitic imidazolate framework-8(Zinc) and 67(Cobalt) [nZIF-8(Zn) and nZIF-67(Co)] were partially exchanged with titanium (Ti) centres to form bimetallic nZIF-8(Zn/Ti) (52% Ti4+) and nZIF-67(Co/Ti) (38% Ti4+) respectively, for enhanced photocatalytic performance. A morphological and structural analysis by scanning electron microscopy, energy dispersive spectroscopy (EDS)-mapping and powder X-ray diffraction showed that the particle size, distribution, and the structural integrity of the Sodalite frameworks of the parent ZIFs were retained during the exchange process to form the new bimetallic Ti-ZIFs. Fourier transform infrared spectroscopy confirmed that no additional chemical bonds were formed during the process. X-ray photoelectron spectroscopy binding energies confirmed the preservation of the Zn(II), Co(II) and Ti(IV) oxidation states, as well as the Ti-content, consistent with inductively coupled plasma-optical emission spectrometry and EDS measurements. The Ti-exchanged ZIFs showed higher activity during the photocatalytic oxidation of hydroquinone in comparison with their parent ZIFs. Their kinetic rates were nearly five times faster than those of the parent ZIFs, with the first-order rate constants k?=?0.189 min?1 for nZIF-8(Zn/Ti) and k?=?0.139 min?1 for nZIF-67(Co/Ti). These catalysts are efficient, stable, and reusable for three photocatalytic cycles without a significant loss of catalytic activity.
Graphical AbstractIn this study, cost-effective, environmentally friendly well-fabricated SnO2/TiO2 nanocomposite synthesized via hydrothermal route and the photocatalytic activity was validated using the (NH3-trz)[Fe(dipic)2] complex under ultra-violet illumination. The structural features of (NH3-trz)[Fe(dipic)2] complex and catalysts were systematically examined by various characteristics. The photoreactivity of the model compound (NH3-trz)[Fe(dipic)2] in water/binary solvent systems was investigated. The rate of photoreaction (k) of nanocomposite (0.1432 s?1) is higher than the SnO2 (0.0373 s?1) and TiO2 (0.1422 s?1) in H2O:PriOH (70:30%) than the rest of the solvents system. The pathways, mechanistic feature of accumulated reactive species on nanocomposite to induce adherent [Fe(dipic)2]? anion and photo-reductive products were studied.
Graphical AbstractA series of novel 4-acetamidophenyl 3-((Z)-but-2-enoyl)phenylcarbamate based chalcone moieties have been synthesized via green chemical Ti/Al(OH)3 and Fe/Al(OH)3 nano catalyzed pathway and spectroscopic authentication of these synthesized molecules were interpreted by FT-IR, 1H-NMR, 13C-NMR, Mass and elemental analysis. In-silico molecular docking studies of the compounds exhibited excellent binding energy (??8.06 kcal and ??8.94 kcal) towards the essential requirements of targeted compounds for EGFR receptor bearing quinazoline inhibitor (PDB ID: 1M17(Lapitinib). UV–Vis and fluorescence spectroscopy measurements evidenced that there is a significant effect on the absorption and emission spectra. Cyclic voltammetry (CV) studies reveal that HOMO and LUMO values of the compounds are evidenced that band along with intra molecular charge transfer character (D-π-A). The red shift maxima (500 nm) of the emission spectra in various solvent were increasing with the solvent polarity.
Graphical AbstractThe objective of the present study was to synthesize Cu doped ZnS nanocore crosslinked with lignocellulose (represented as Cu:ZnS-lignocellulose nanocomposite) for antifungal action against the devastating tea blister blight pathogen Exobasidium vexans. The characteristic features of the nanocomposite were analyzed via different physicochemical techniques like FTIR, XRD, XPS, SEM, SEM–EDX, Elemental mapping, PCS, and UV-PL studies. The FTIR and XPS investigations revealed the crosslinking between lignocellulose and the Cu:ZnS. The presence of lignocellulose was seen to attribute a potent antifungal efficacy, also enhancing the stability of the resulting nanocomposite in aqueous suspensions. The antifungal efficacy confirmed through disk diffusion and broth dilution assays have a maximum zone of inhibition of 1.75 cm2 and a MIC50 of 0.05 mg/ml against E. vexans. Additionally, the antisporulant activity was evident as the basidiospores failed to germinate in presence of the Cu:ZnS-lignocellulose nanocomposites. This shows potential for stemming the rapid infectivity of E. vexans by achieving disease inhibition at the early stage. Finally, the comparison with two commonly used commercial fungicides (copper oxychloride and fluconazole) demonstrated?>?tenfold higher antifungal activity for Cu:ZnS-lignocellulose nanocomposites.
Graphical abstractHere, we report a facile synthesis of porous zinc-titanium oxide based mixed oxide nanoparticles having Zn/Ti molar ratio 1:2 based on evaporation-induced sol–gel route using Pluronic triblock copolymer P123 as a template. Use of volatile ethanolic media during the evaporation-induced self-assembly (EISA) method facilitates the formation of Zn–Ti mixed oxide heterostructure. Powder XRD data reveals that the composite material displayed ZnTiO3/TiO2 phases. Morphology, composition, porosity, nanostructure and thermal stability have been systematically investigated using small angle powder XRD, FE SEM-EDS, TEM, N2 sorption, FT IR and TG-DTA techniques. The observed BET surface area of Zn–Ti mixed oxide was 231 m2 g?1 with a typical mesopore diameter (~?5 nm) mostly arising from interparticle void space. The Zn–Ti mixed oxide catalyst showed bifunctional activity for Friedel–Craft benzylation of aromatics using benzyl chloride as well as partial oxidation of olefins under mild reaction conditions using dilute aqueous H2O2 as oxidant.
Graphical AbstractZn–Ti based porous nanoparticles synthesized using Pluronic P123 copolymer surfactant via EISA method has shown a very high surface area of 231 m2 g?1 and a significant bifunctional role for liquid phase oxidation and benzylation reaction.
This study depicts the electrochemical synthesis of nanocomposites based on polyaniline nanorods (NRs) wrap with reduced graphene oxide (PANI–rGO) on ITO substrates for photocurrent generation, photodegradation, and antibacterial applications. The synthesis of PANI–rGO nanocomposites was elaborated by the incorporation of rGO into PANI thin films during electropolymerization in the presence of sulfuric acid. The synthesis of rGO was done by modification on the well-known Hammer’s method. The thin film nanocomposites were characterized by X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (FESEM), UV–Visible and electrochemical photocurrent spectroscopy. FESEM revealed the formation of PANI NRs with diameters of between 50 and 150 nm. The XPS was employed to confirm the compositions of the PANI–rGO nanocomposites. From photoelectrochemical results, the generated photocurrent was improved in the presence of rGO in PANI NRs. Whereas experimental findings show that the introduction of rGO into PANI improved the photoresponse from 7 to 13 µA cm?2. Integration of 3D rGO into PANI results in better photocatalytic performance for the degradation of Congo red (CR). The enhanced photocatalytic activity with the presence of rGO revealed the good potential of PANI-GO nanocomposites for dye degradation. The effective removal of CR of up to 90% has been observed in an acidic medium and is acceptable compared to the surface area of the substrate. At optimum conditions, also the nature of the antibacterial activities has been investigated by ITO/PANI and ITO/PANI–rGO thin films, and the results have shown exhibited antibacterial activity against the growth of E. coli gram-negative bacteria.
Graphical AbstractNi–Mo2C and Ni–WC were evaluated in dry reforming of methane employing different CH4/CO2 ratios. Ni–Mo2C remained active under an excess of CH4, but deactivation occurred under an excess of CO2. Ni–WC was resistant to excess of CO2 but showed carbon deposition under excess of CH4.
Graphic AbstractAn efficient solvent-free catalyst system for hydrosilylation of aldehydes and ketones was developed based on iron pre-catalyst Fe2(CO)9/C6H4-o-(NCH2PPh2)2BH. The reactions were tolerant of many functional groups and the corresponding alcohols were isolated in good to excellent yields following basic hydrolysis of the reaction products. The reaction is likely catalyzed by an in situ generated pincer ligated iron hydride complex.
Graphic AbstractAn osmotic urine fuel cell (OsUFC) was employed to recover water, energy, and nutrients from urine. The recovered water was used to reduce the salinity of the brine solution. The water flux of concentrated urine (2.83 LMH) was lower than that of diluted urine (4.72 LMH); however, the current output was higher due to the high conductivity. Besides, the water flux of concentrated urine was improved significantly from 1.91 to 5.09 LMH by varying NaCl concentrations from 0.5 to 3 M, respectively. Similarly, the current production was enhanced from 4.07 to 61.20 mW m?3 for the NaCl concentrations from 0.5 to 3 M, respectively. Moreover, OsUFC displayed nutrient rejection rates of 100%, 90%, 99%, and 96% for PO43?, TN, NH4+–N, and TOC, respectively. Furthermore, OsUFC showed salinity reduction efficiencies of 25.15% and 32.28% for Na+ and Cl?, respectively.
Graphical abstract3D metal–organic frameworks (MOFs) can be appropriate templates for the fabrication of nanomaterials due to they have active sites exposed on the channel or surface, which thus provide them with improved catalytic performance. In this study, a 3D cobalt-based MOF [Co(H2bpta)]n (Co-MOF), where H4bpta denotes 2,2′,4,4′-biphenyltetracarboxylic acid, has been constructed with the use of a ligand with a high carbon content. On this basis, a 2D magnetic carbon-coated cobalt nanoparticle composite (Co@C) was prepared by using the title MOF under different temperatures. Magnetic Co@C can readily absorb dye from the solution and can thus act as an inexpensive and fast-acting adsorbent. Moreover, we have explored the adsorption isotherms, kinetics and thermodynamics of the anion dyes in detail. The adsorption capacity of the Co@C-800 for investigated methyl orange (MO) and congo red (CR) dyes were 773.48 and 495.66 mg g?1, respectively. It is noteworthy that MO adsorption is higher in existing materials. Thermodynamic studies suggest that the adsorption processes are spontaneous and exothermic. This study opens a new insight into the synthesis and application of carbon-based materials that enable the selective removal of organic dyes.
Graphical AbstractA Co-MOF has been solvothermal synthesized and structurally characterized, which was used as a combined catalyst and carbon source for the synthesis of magnetic Co@C. Interestingly, the as-grown Co@C-800 exhibits high-performance selective adsorption of anionic dyes (MO and CR) with high adsorption capacities.
Micro-mesoporous aluminosilicates based on ZSM-5 zeolite, obtained by a dual template method, as well as in the presence of a dual-functional template (i.e. a Gemini-type surfactant), were tested in the oxidation of furfural with hydrogen peroxide. Even substantial changes in acidity and porosity of the catalysts result in minor variations of selectivity towards the desired products. Application of the synthesized zeolite-based materials in the oxidation of furfural with hydrogen peroxide leads to formation of 2(5H)-furanone (yield up to 28.5%) and succinic acid (up to 19.5%) as the main C4 reaction products. The kinetic model developed previously to treat the results for oxidation of furfural over sulfated zirconia was able to describe the data also for micro-mesoporous aluminosilicates.
Graphical AbstractThis work proposed a new path to synthesize Ni-phyllosilicate through the reaction of nickel hydroxide and silica sol on the surface of Ni-foam to form the monolithic Ni-phyllosilicate/Ni-foam catalyst. Ni-phyllosilicate could reprint the morphology of nickel hydroxid and firmly anchor on the framework of Ni-foam, which obtained fine Ni particles of 2.8 nm after reduction in H2 at 650 °C, resulting in high catalytic activity for CO2 methanation. In addition, the Ni-phyllosilicate/Ni-foam catalyst showed high long-term stability in a 100 h-lifetime test owing to the combined effects of surface confinement of Ni-phyllosilicate, firm anchoring between Ni-phyllosilicate and Ni-foam, as well as the high heat transfer property of Ni-foam.
Graphical AbstractThe demand for clean water has been increasing around the world. In this study, graphene oxide/Fe3O4/Ag nanomaterials with different graphene oxide:Fe3O4 ratios were prepared and determined the best formulations for water treatment. Ag nanoparticles were incorporated into the materials by a green reduction method using Cleistocalyx Operculatus leaf extract for the first time. The synthesized materials were characterized by FTIR, Raman, XRD, FESEM, EDX and VSM methods. The characterizations confirm that the materials have been prepared successfully with various element compositions and can be separated by outer magnetic fields. The results show that the GF31A sample with graphene oxide:Fe3O4 ratio of 3:1 and about 5 wt.% Ag in the composition exhibits the highest efficiency for chemical oxygen demand (COD), total nitrogen (TN) and PO43? removals. This material also induces good antibacterial and antifungal activity on harmful gram (+), gram (?), and fungi microorganisms such as Staphylococcus aureus, Salmonella enterica, Candida albicans with small IC50 values (from 1.5 to 11.1 mg/L). More than 70% of COD, TN, PO43? and 100% of E. coli have been removed from two real water samples treated with GF31A (0.1 g/100 mL). The results reveal that GF31A is a potential agent for water treatment application. Besides the newly using of Cleistocalyx Operculatus in the synthesis, this is also the first time various graphene oxide/Fe3O4/Ag materials have been systematically investigated for both water decontamination and disinfection with the ease of magnetically separation.
Graphical AbstractA Cd(II)-based metal–organic framework (Cd-MOF), named [Cd2(taptp)(bbibpy)(H2O)·2H2O·DMF]n, was successfully constructed under the condition of solvothermal (H2taptp?=?2-(4-(tetrazol-5-yl)phenoxy)terephthalic acid, bbibpy?=?5,5′-bis(benzimidazol-2-yl)-2,2′-bipyridine, DMF?=?N,N′-dimethylformamide). Cd-MOF was characterized by X-ray single-crystal diffraction, elemental analysis and thermogravimetric (TG) analysis. X-ray single crystal diffraction analysis reveals that Cd-MOF has a two-dimensional (2D) framework structure and crystallizes in the monoclinic system, space group P21/c. The fluorescence quenching experimental results show that Cd-MOF is potential fluorescent material that can selectively and sensitively fluorescent sensing Nitrobenzene. The fluorescence quenching of Cd-MOF belongs to dynamic quenching based on the Stern–Volmer model. The concentration-fluorescence experimental result shows that the detection limit of Cd-MOF for NB is 7.16?×?10–8 M, based on 3σ/Ksv.
Graphical AbstractA Cd-MOF has been successfully synthesized and characterized. The fluorescence quenching experiments results showed Cd-MOF exhibits sensitive response to NB with detection limit of 7.16?×?10–8 M.
In order to further improve the catalytic activity and stability of heterogeneous acid catalysts, a polystyrene microspheres modified sulfonic acid-based catalyst (PS-SO3H) was prepared. PS-SO3H was characterized by Fourier transform infrared spectroscopy, powder X-ray diffraction, scanning electron microscope, transmission electron microscope, N2 adsorption–desorption, and X-ray photoelectron spectroscopy. Catalytic efficiency was determined using the reaction of furfuryl alcoholysis to ethyl levulinate (EL). The obtained results showed that PS-SO3H had excellent catalytic performance, with EL yield of 94.7%. In addition, PS-SO3H was easily separated from the reaction system and recycled multiple times without significant reduction in activity. High catalytic activity stemmed from the effect of Brønsted acid sites and appropriate structural properties.
Graphical Abstract