A new composite cation exchange material poly-o-toluidine stannic molybdate was synthesized by the incorporation of an organic polymer poly-o-toluidine into the matrices of inorganic precipitate of ...stannic molybdate. The experimental parameters such as concentration, mixing ratio and pH were established for the synthesis of the material. The material was found to be granular and can be conveniently used in column operations. The newly synthesized composite material exhibits improved thermal stability, ion exchange capacity and selectivity for toxic heavy metal ions. The material is characterized using various analytical techniques like FTIR, TGA, DTA, XRD, SEM, TEM and elemental analysis. The X-ray diffraction study showed semicrystalline nature of the material. The pH titration studies revealed monofunctional weak acid behavior of the exchanger. The elution behavior of the exchanger was also examined. The distribution coefficient studies of metal ions on the material were performed in different solvent systems and the material was found to be selective for Hg
2+ and Pb
2+ ions. On the basis of distribution coefficient values, some analytically important binary separations of metal ions viz. Al
3+–Hg
2+, Cu
2+–Hg
2+, Cu
2+–Th
4+, Zn
2+–Hg
2+, Bi
3+–Hg
2+, Cd
2+–Pb
2+ were achieved on poly-o-toluidine stannic molybdate columns. Hg
2+ and Pb
2+ ions were also selectively separated from synthetic mixtures of metal ions. In order to demonstrate the practical utility of the material, quantitative separations of Hg
2+ from thermal power plant effluents and of Pb
2+ from lead storage battery industry wastes have been achieved.
A nanocomposite acrylamide tin(IV) silicomolybdate (
AC/TSMNC
) was chemically synthesized by the sol–gel technique in surfactant medium at room temperature. The synthesis conditions, such as ...reactant concentrations, pH and temperature were varied to optimize the ion exchange properties of the nanocomposite ion exchange material. The ion exchange capacity was found to be 1.92 meq/g for Na
+
. The nanocomposite was characterized on the basis of chemical composition, Fourier-transform infrared spectroscopy, X-ray diffraction (
XRD
), scanning electron microscopy (
SEM
) and transmission electron microscopy (
TEM
) studies. The interpretation of the XRD pattern indicated its semi-crystalline nature. The diamond shape morphology was observed in SEM studies. The particle size of the material was in the range of 50‒100 nm as indicated by TEM. Sorption studies were performed in a number of solvent systems showing high selectivity for Pb(II) and Ni(II) in synthetic mixtures. On the basis of distribution coefficient studies several binary separations of metal ions, viz. Mg
2+
–Pb
2+
, Mg
2+
–Ni
2+
, Sr
2+
–Pb
2+
, Sr
2+
–Ni
2+
, Zn
2+
–Pb
2+
, Zn
2+
–Ni
2+
were achieved quantitatively on acrylamide tin(IV) silicomolybdate columns. The quantitative separation of Ni
2+
and Zn
2+
was also achieved on a commercially available pharmaceutical formulation (Rxplus). Photocatalytic degradation of methylene blue dye onto AC/TSMNC was investigated for 3.5 h under solar light at a wavelength of 664 nm. The rate of methylene blue dye photodegradation onto AC/TSMNC was found to follow the pseudo-first-order kinetic model.
In this work, a novel metal-organic framework ZIF-8 is fabricated with poly-o-anisidine/zinc oxide (POA/ZnO) to obtain poly-o-anisidine/zinc-oxide nanohybrid material (PAZ@ZIF-8) via in-situ approach ...at room temperature. The characteristics of as-prepared nanocomposites were investigated by employing sophisticated techniques such as SEM, TEM, FTIR, XRD, and SEM-EDAX. The PAZ@ZIF-8 nanohybrid material exhibits a significant rational function for the adsorption of highly toxic organic pollutants. The as-synthesized nanohybrid materials are employed to remove Malachite Green (MG) dye from aqueous solutions. PAZ@ZIF-8 has displayed excellent removal efficiency towards the removal of MG dye, and almost 96% of the dye is removed within a very short period as compared to ZIF-8 (34%) and POA/ZnO (61%), respectively. The experiments were carried out at different pH values (3 - 9) and adsorbent amounts (1 - 1.5 mg/g). The Langmuir sorption model is a better fit for the removal of MG dye on PAZ@ZIF-8, and the maximum adsorption capacity of 613 mg/g is observed. The sorption kinetics of MG dye on PAZ@ZIF-8 is well followed by the pseudo-second-order model. PAZ@ZIF-8 has shown excellent recyclability for three consecutive cycles, and almost 90% of the dye is removed in the third cycle. This research will overlay the road to developing innovative nanohybrid 3D-MOF adsorbent systems for detoxification and wastewater treatment.
Herein, Nd(NO3)3(H2pzdca) n (MA-1) was synthesized from a reaction of 2,3-pyrazinedicarboxylic acid H2Pzdca as an organic linker with salt of Nd(III) under solvothermal conditions. The detailed ...structural analysis for crystals was performed utilizing single-crystal X-ray diffraction (SCXRD). After that, the neodymium-based coordination polymer (MA-1) crystal was directly generated upon the surface of functionalized carbon nanotubes (F-CNTs) through bonds or affinity between F-CNTs and MA-1 via the solvothermal approach. Meanwhile, the existence of F-CNTs does not affect the production of MA-1 crystals. FT-IR, PXRD, SEM, TEM, and SCXRD studies were used to characterize the crystalline material, MA-1 and MA-1@CNT. To investigate the MA-1@CNT sensing properties, Pb(II), As(III), Cr(VI), and nitrobenzene (NB) were utilized as analytes. It is worth mentioning that MA-1@CNT developed as a susceptible sensor exhibits a fluorescence “turn-on” response for Pb(II) and As(III) ions, while a fluorescence “turn-off” response in the case of Cr(VI) and NB with significantly low limit of detection (LOD) values of 15.9 for Pb(II), 16.0 for As(III), 76.9 for Cr(VI), and 21.1 nM for NB, which are comparable with the lowest LOD available in the literature. Furthermore, MA-1@CNT could be conveniently regenerated and reused for at least three cycles by simply filtering and washing with water several times. The sensing mechanism is ascribed to the inner filter effect owing to the overlap between the emission and/or excitation bands of MA-1@CNT with the absorption bands of Cr(VI) and NB. In contrast, the fluorescence enhancement in the case of Pb(II) and As(III) could be correlated to the chelation-enhanced fluorescence phenomenon. These results indicate that MA-1@CNT is an ideal sensor for Pb(II), As(III), Cr(VI), and NB recognition.
The drug binding to serum protein (SP) is an area of intense research in evaluating drug candidates. Thus, composite material based on chitosan (CS), and amoxicillin tri hydrate (AMOT) were designed ...in order to evaluate the release of AMOT@CS NPs and it’s binding with BSA under physiological condition. The inclusion of 2% v/v T80 in the CS NPs enabled in vitro release of AMOT, at 298 K and pH 7.4 up to 68.03%. This study also was undertaken to compare and explore the binding of potential chemotherapeutic antibacterial drug Amoxicillin trihydrate (AMOT) and AMOT@Chitosan nanoparticles (AMOT@CS NPs) with a model protein bovine serum albumin (BSA) by fluorescence spectroscopy, synchronous fluorescence spectroscopy, Ultraviolet–visible (UV–vis) absorption, and CD spectroscopic techniques. Experimental results indicated that AMOT and AMOT@CS NPs could bind with BSA and quench the fluorescence of BSA via static mechanism. The interactions among BSA with AMOT, AMOT/T80 and AMOT@CS NPs were evidenced by substantial changes in the BSA secondary structure, as revealed by circular dichroism. The findings of thermodynamic parameters revealed that the binding reaction in both systems was exothermic and spontaneous, enthalpically drivenand that the hydrogen bonding and Vander Waals forces played a vital role to achieve optimal interaction between AMOT/ AMOT@CS NPs and BSA.
Stannic silicomolybdate was synthesized at pH 0.63 .The experimental parameters such as order of mixing, mixing volume ratio, pH, stirring time, drying temperature were established for the synthesis ...of the material. The ion exchange capacity of Ca
2+ was improved from 0.53 to 1.73
meq/g for this newly synthesized material. The reproducibility of the product formed was checked. The exchanger was characterized on the basis of chemical composition, thermal and chemical stability, FTIR, TGA, DSC, X-ray and SEM analysis. The scanning electron microscopy of the material shows a regular diamond shape morphology. The presence of uniform morphology also indicated the absence of impure phases. The X-ray diffraction study showed the amorphous nature. Distribution coefficient studies of the metal ions on this material were performed in solvents having different acid dissociation constants namely trichloroacetic acid, formic acid and acetic acid. The effect of dielectric constants of solvents was studied by using dimethylsulfoxide; formic acid, acetic acid and trichloroacetic acid. The effect of temperature on the distribution coefficient was explored. It was finally concluded that 45
°C appeared to be the most favorable temperature. Important quantitative separations of metal ions in ternary mixtures included Ni
2+–Co
2+–Pb
2+, Cu
2+–Cr
3+–Pb
2+, Cu
2+–Fe
3+–Pb
2+, Th
4+–Zr
4+–Sn
4+, Cr
3+–Ni
2+–Fe
3+, Cu
2+–Ni
2+–Ag
+ and Fe
3+–Zn
2+–Al
3+. The practical potential of stannic silicomolybdate was explored by separating Cu
2+ and Zn
2+ quantitatively in synthetic mixtures as well as in commercially available brass samples.
A highly efficient and recyclable catalysts, mesoporous poly o-anisidine titanium phosphate (POA-TP) and Sm co-doped POA-TP have been synthesized by chemical in situ polymerization in micellar media. ...Mesoporous nanocomposites of POA-TP and Sm@ POA-TP have been characterized by instrumental techniques such as FTIR, XRD, TGA-DTA, SEM, TEM, PL, electron-paramagnetic resonance (EPR) spectroscopies & UV–vis diffuse reflectance spectroscopy (DRS) and their photocatalytic performance were investigated based on the degradation of methylene blue (MB) and malachite green (MG) dyes. The optical properties revealed that the band gap of Sm@POA-TP was reduced from 3.76 eV (POA-TP) to 3.70 eV (Sm@POA-TP) due to the presence of new donor energy levels with Sm3+ loading. The experimental results indicated that the enhanced photo-catalytic performance with Sm@POA-TP could be attributed to the increased optical absorption and efficient separation and migration of photo-produced charge carriers with decreasing the recombination of electrons–holes creating from doping effects. Cyclic voltammetry study was employed to investigate the redox behaviors and the current producing ability of the materials. The distribution coefficient values were used as the basis for the separation and determination of metals in water samples. The analytical column separation efficiency was explored by achieving binary separations of metal ions like Mg2+–Pb2+, Mg2+– Fe2+, Sr2+–Pb2+, Sr2+–Fe2+, Zn2+–Pb2+, Zn2+ – Fe2+. This study could lead to the synthesis of low cost photocatalysts highly efficient for the removal of environmentally hazardous dyes and metal ions from aqueous solution.
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•Mesoporous Sm@POA-TP and POA-TP nanocomposites synthesized by facile chemical in situ polymerization in micellar media.•Sm@POA-TP and POA-TP have been characterized by FTIR, SEM/EDX, TEM, TGA-DTA, XRD, EPR, U.V–vis (DRS) analyses.•Sm@POA-TP and POA-TP show high efficient and recyclable photocatalytic activities for degradation of MB and MG dyes.•Some binary separations of heavy metals were achieved quantitatively.
A new inorganic cation exchanger titanium(IV) molybdosilicate has been synthesized. The effect of experimental parameters such as mixing ratio of reagents, temperature, and pH on the properties of ...material has been studied. The material was characterized on the basis of chemical composition, thermal and chemical stability, X-ray diffraction, FTIR, TGA and SEM studies. The exchanger behaves as a monofunctional acid in alkali systems and bifunctional in alkaline earth system. The cation exchange capacity for Na
+ was found to be 0.74
mequiv./g ions. The adsorption behavior of metal ions in different solvent systems namely acetic acid, formic acid, dimethylsulfoxide, phenol, triton, formamide and dimineralized water has been studied. The analytical applications of the material have been explored by achieving some binary as well as ternary separations from aqueous solution on its columns. In order to demonstrate analytical utility of titanium(IV) molybdosilicate, quantitative separation of Fe
3+ and Zn
2+ contents of a commercially available pharmaceutical sample viz Fefol-Z has been performed on its column.
Neodymium-doped polyaniline supported Zn-Al layered double hydroxide (PANI@Nd-LDH) nanocomposite has been prepared via an ex-situ oxidative polymerization process. The as-prepared nanocomposite shows ...selective fluorescence detection and adsorption of hexavalent chromium Cr(VI) within a short period. The fluorescence intensity of PANI@Nd-LDH decreases linearly with Cr(VI) concentrations ranging from 200 ppb to 1000 ppb with a limit of detection (LOD) of 1.5 nM and a limit of quantification (LOQ) of 96 nM. The sensing mechanism can be ascribed by the inner filter effect of Cr(VI), the intercalation of Cr(VI) within the intergallery region of LDH, and the synergistic affinity of metal ions along with the polymer chain for Cr(VI). The adsorption performance of PANI@Nd-LDH nanocomposite is evaluated for Cr(VI) from wastewaters, which displayed high removal capacity towards Cr(VI) (219 mg/g) as compared on bare Nd-LDH (123 mg/g) and LDH (88 mg/g) respectively. The adsorption of Cr(VI) on PANI@Nd-LDH depends on the pH of the aqueous solution. The adsorption isotherm and kinetics are supported by the Langmuir model and pseudo-second-order model, respectively. Owing to the highly sensitive detection and adsorption of Cr(VI) from aqueous water samples demonstrated the potential application of PANI@Nd-LDH as an excellent environmental probe can be exploited.
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•PANI@Nd-LDH was synthesized and employed for selective detection and removal of Cr(VI) in water.•PANI@Nd-LDH shows excellent sensitivity for the detection of Cr(VI) at ppb level.•The high adsorption capacity for Cr(VI) (219 mg/g) is attributed to complexation and ionic interactions.•The detection of Cr(VI) is based on inner filter effect and ionic interactions.•PANI@Nd-LDH could possibly emerge as an excellent adsorbent as well as sensor for the removal of Cr(VI) from wastewater.
Functional properties of two-dimensional (2D) nano-hybrid materials have received much attention in advanced research and technology due to exponential need of green energy, clean water and pollution ...free environment. Nowadays, it is a demanding apprehension to develop advanced stratigies for the synthesis of nano-hybrid multifunctional materials such as graphene oxide supported layered double hydroxides (GO/LDHs) by employing different chemical routes with extraordinary properties that can lead to novel technologies for identifying and addressing the current global environmental challenges. Starting with paradigm graphene doped with other 2D materials including layered metal hydroxides (LMHs), mixed metal oxides (MMOs), metal nitrides (MXenes) and metal carbides have gradually emerged as potential hybrid nanomaterials for the removal of environmental pollutants. The current review highlights the ongoing advances of hybrid LDHs-supported nanomaterials in various fields. Association of LDHs with carbon-based nanomaterials (graphene/graphene oxide, carbon quantum dots, carbon nanotubes/nanofibers) exposed that these nanocomposite materials have outstanding environmental applications owing to their distinctive combination of architectural properties, exfoliation, and nanoarchitectural topological transformation features. GO/LDHs have many potential applications in wastewater treatment, adsorption and separation of toxic gases from environment, environmental sensors and catalysts. Sooner, the LDHs-supported nanomaterials are anticipated to open an innovative eco-friendly way for their possible applicability in environmental systems.
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