4-(4-Pyrid­yl)pyridinium bis­(pyridine-2,6-dicarboxyl­ato)ferrate(III) tetra­hydrate

In the title compound, (C10H9N2)[Fe(C7H3NO4)2]·4H2O or (bpyH)[Fe(pydc)2]·4H2O, the asymmetric unit contains an [Fe(pydc)2]− (pydcH2= pyridine-2,6-dicarboxylic acid) anion, a protonated 4,4′-bipyridine as a counter-ion, (bpyH)+, and four uncoordinated water mol­ecules. The anion is a six-coordinate complex with a distorted octa­hedral geometry around the FeIII atom. A wide range of non-covalent inter­actions, i.e. O—H⋯O, O—H⋯N and N—H⋯O hydrogen bonds, ion pairing, C—O⋯π [3.431 (2) Å] and C—H⋯π stacking inter­actions result in the formation of a three-dimensional network structure

Design, synthesis, and characterization of a novel Zn(II)-2-phenyl benzimidazole framework for the removal of organic dyes

Abstract A novel Zn (II) organic framework comprising 2-phenyl benzimidazole (ZPBIF-1) was synthesized by using a solvothermal method. The characterization of the synthesized MOF was performed utilizing XRD, SEM, FT-IR, 1H-NMR, 13C-NMR, MS, XPS, TG/DTA, and N2 sorption analysis. ZPBIF-1 was successfully utilized to remove Acid red 88, Basic Violet 14, Basic Blue 54, and Congo red dyes in aqueous solutions. In this study, some parameters, including adsorbent dosage, initial dye concentration, contact time, temperature, and pH, were examined. To evaluate the experimental data, Freundlich, Langmuir, Temkin, and Dubinin-Radushkevich isotherm models were used. In this case, Langmuir is the most suitable model. Several kinetic models, including First-order, pseudo-first-order, second-order, and Pseudo-second-order kinetic models, Elovich's, and Weber's intraparticle diffusion models, were utilized to comprehend the detailed adsorption process. According to the pseudo-second-order kinetic model, dye sorption kinetics is best described. In addition, thermodynamic parameters like enthalpy (ΔH°), Gibbs free energy (ΔG°), and entropy (ΔS°) were also achieved and analyzed. The experimental studies thus suggest that Zn (II) metal–organic framework based on 2-phenyl benzimidazole could be a promising candidate for eliminating dyes from aqueous solution. Hence, the experimental studies suggest that a Zn (II) metal–organic framework based on 2-phenylbenzimidazole could be a promising candidate for eliminating dyes from aqueous solution. The maximum adsorption capacity of ZPBIF-1 was 1666.66, 1250, 1000, and 1250 mg/g for Acid red 88, Basic violet 14, Basic blue 54, and Congo red dyes, respectively. Furthermore, this method was used to remove contaminant dyes from textile wastewater, and an acceptable result was obtained

Influence of mild alkaline treatment on the cellulosic surfaces active sites

Agro-residues fibers are inexpensive environmentally friendly alternatives to synthetic fibers in fiber reinforced polymer composites. The natural fiber properties and bondability with adhesive can be modified by subjecting the fibers to a pre-treatment procedure. The knowledge ofthe modified fibers sur face properties is essential to explain and predict their applications. The present study is focused on the effect of alkaline treatment on the surface characteristics of stalk fibers from rapeseed, tobacco, cotton, lemon balm and kiwi. The chemical composition of fibers and Fourier transform infrared spectroscopy show components extraction and the X-ray diffraction show improvement in the crystallinity index of the treated fibers. But only the IGC analysis allows us to know in detail the alterations on the fiber surface and the effect on the adhesion of the fibers. IGC shows that alkaline treatment produces changes in the nature and number of the active sites, responsible for the physico-chemical activity of the surface of the fibers. The fiber hydrophobicity was improved by the increase of more energetic and active sites in the surface. Also,the creation of new basic active sites and removal of acidic active sites from the fiber surface due to alkaline treatment has been clearly shown.info:eu-repo/semantics/publishedVersio

Synergistic potential in spinel ferrite MFe2O4 (M = Co, Ni) nanoparticles-mediated graphene oxide: Structural aspects, photocatalytic, and kinetic studies

Abstract The existence of artificial dyes in water is a significant environmental concern, as it can lead to poor water quality. Photodegradation is becoming an increasingly popular method for treating water contaminated with dyes. In this study, the photodegradation of Reactive Red 66 and Reactive Red 120 dyes, as well as textile wastewater, was investigated under UV and visible light irradiation. To enhance the photoresponse of the MFe2O4 (M = Co, Ni) nanoparticles, modifications were made by incorporating graphene oxide. The MFe2O4 nanoparticles and MFe2O4/GO nanocomposite photocatalysts were subjected to several characterization techniques, including FT-IR, Raman spectroscopy, XRD, DRS, zeta potential, VSM, TGA, DSC, BET, SEM, and EDAX analysis. Experiments were conducted to optimize several key parameters involved in the photodegradation process, including pH, photocatalyst dosage, initial dye concentration, and irradiation time. The removal efficiency of Reactive Red 66 and Reactive Red 120 dyes using CoFe2O4 nanoparticles was found to be 86.97 and 82.63%, respectively. Also, the removal percentage of these dyes using CoFe2O4/GO nanocomposite photocatalyst was 95.57 and 90.9% for Reactive Red 66 and Reactive Red 120, respectively. Experiments found that NiFe2O4 nanoparticles removed 90.92% of Reactive Red 66 dye and 84.7% of Reactive Red 120 dye. The NiFe2O4/GO nanocomposite photocatalyst showed even higher removal efficiencies, degrading 97.96% of Reactive Red 66 and 93.44% of Reactive Red 120. After three days of exposure to visible light irradiation, the removal percentage of Reactive Red 66 using MFe2O4 and MFe2O4/GO nanocomposite was investigated

Investigation on the surface properties of chemically modified natural fibers using inverse gas chromatography

This paper presents the application of inverse gas chromatography (IGC) technique for characterization and comparison of the surface properties of the natural fibers as reinforcement fillers in wood plas tic composites. The effects of chemical modification using 1% NaOH were also studied. The fibers used for this work were Iranian cultivated eucalyptus, spruce, bagasse, and wheat straw. Chemical composi tion of fibers was found to be modified after treatment as characterized by Fourier transform infrared spectroscopy (FTIR). The crystallinity of fibers and the specific interaction was improved by the alkaline treatment, with more relevance to the agro-fibers. The IGC shows also a general increase in the wettability of the modified fiber when compared with the raw (unmodified) samples. Alkaline treatment achieves the best overall improvement in the properties evaluated of the agro-fibers when compared to the wood fibers.info:eu-repo/semantics/publishedVersio

Hydrogen bond-mediated self-assembly of Tin (II) oxide wrapped with Chitosan/[BzPy]Cl network: An effective bionanocomposite for textile wastewater remediation

A novel and efficient bionanocomposite was synthesized by incorporating SnO into chitosan (Ch) and a room-temperature ionic liquid (RTIL). The bionanocomposite was synthesized in benzoyl pyridinium chloride [BzPy]Cl to maintain the unique properties of SnO, chitosan, and the ionic liquid. Adsorption and photodegradation processes were applied to evaluate the bionanocomposite for removing azo and anthraquinone dyes and textile wastewater. SnO/[BzPy]Cl and SnO/[BzPy]Cl/Ch samples were prepared and characterized using various techniques, including FT-IR, SEM, XRD, EDAX, XPS, DSC, TGA, nitrogen adsorption/desorption isotherm, and DRS analysis. SEM analysis revealed a hierarchical roughened rose flower-like morphology for the biocomposite. The band gap energies of SnO/[BzPy]Cl and SnO/[BzPy]Cl/chitosan were found to be 3.9 and 3.3 eV, respectively, indicating a reduction in the band gap energy with the introduction of [BzPy]Cl and chitosan. SnO/[BzPy]Cl/Ch showed high removal rates (92–95 %) for Fast Red, Blue 15, Red 120, Blue 94, Yellow 160, and Acid Orange 7 dyes. The adsorption kinetics followed a pseudo-second-order model.In addition, the effect of different photodegradation parameters such as solution pH, dye concentrations, contact time, and amount of photocatalyst, was studied. Given the optimal results obtained in removing azo and anthraquinone dyes, the SnO/[BzPy]Cl/Ch nanocomposite was used as an efficient nanocomposite for removing dyes from textile wastewater. The highest removal efficiency was found to be 95.8 %, obtained under ultraviolet and visible light. Furthermore, BOD and COD reduction analysis showed significant reductions, indicating the excellent performance of the photocatalyst

Preparation, characterization and catalytic application of some polyoxometalates with Keggin, Wells-Dawson and Preyssler structures

1725-1729Dibutylphthalate has been prepared via esterification reaction in the presence of some solid acidic catalysts. Transition metal polyoxometalates with Keggin (K3[PMo6W6O40], K3[PMo12O40], K4[SiMo12O40], K4[SiW12O40], Na7[PW11O39]), Wells-Dawson (K6[P2W18O62]), and Preyssler structures (K14[NaP5W30O110]) have been synthesized and characterized. The reactivity of these catalysts has been studied for the preparation of dibutylphtalate by esterification reaction of phthalic anhydride and 1-butanol. Among the various acidic catalyst used, K3[PMo6W6O40] showed the best reactivity and efficiency compared to other catalysts