Vikrant Yadav

Synthesis and characterization of different metal oxide and GO composites for removal of toxic metal ions

ABSTRACT This manuscript deals with graphene oxide (GO) and GO–metal oxide composite for heavy metal adsorption. Metal oxide–GO composites e.g. Fe3O4–GO and Mn3O4–GO have been prepared and explored for heavy metals e.g. lead, chromium, nickel, cadmium etc. adsorption from the water. Metal oxide–GO composites have been prepared through respective techniques. The various characterizations of the nanocomposites viz. structural and thermal have been analysed by transmission electron microscopy, thermogravimetric analyser etc. Different concentration of heavy metal has been taken to examine the efficiency of composites towards adsorption. Furthermore, effect of time on adsorption has also been evaluated. Metal oxide–GO composites illustrate better results as compared to GO showing the usability of composites for heavy metal adsorption for the production of clean water.

Zn-MOF@SPES composite membranes: synthesis, characterization and its electrochemical performance

ABSTRACT Herein, the applicability of MOF-based composite ion exchange membranes have been explored. Series of membranes have been synthesized by varying Zn-MOF content in SPES matrix. Number of spectroscopic techniques were used to characterize the successful synthesis of Zn-MOF and composite membranes. Physicochemical properties of composite membranes have been evaluated and observed to be enhanced. Composite membranes have been subjected to salt removal efficiency through electrodialysis, and observed that Z-2 membrane shows best flux and salt removal efficiency than others, which were 1.72 molm−2h−1 and 1.0 kWhkg−1 respectively with superior electro-chemical performance.

Synthesis and characterization of aluminium modified graphene oxide: an approach towards defluoridation of potable water

Abstract An approach towards the synthesis of aluminum modified graphene oxide (GO) has been studied in the present manuscript. Graphene oxide has been modified by the aluminum sulfate followed by alkalization to synthesized Al-GO composite. GO and Al-GO composite has been characterization by the means of different techniques i.e. XRD, FT-IR, FT-Raman, TEM, SEM, TGA and elemental mapping. Analysis confirmed the formation of GO and Al-GO composite. The prepared GO composite has been checked for the removal of fluoride from the potable water with different initial concentration of fluoride ions. Composite shows it’s effectiveness for the removal of fluoride throughout the pH range. The maximum adsorption capacity and Langmuir constant determined for the adsorbent dose of 1u2009g L−1 are found to be 38.31u2009mg g−1 and 0.5252u2009L mg−1 respectively.GRAPHICAL ABSTRACT Graphical Abstract

Synthesis of Chloride-Free Potash Fertilized by Ionic Metathesis Using Four-Compartment Electrodialysis Salt Engineering

A sustainable approach for the production of high-purity potash fertilizers devoid of chloride is highly needed. Conventional preparation processes for chloride-free potash fertilizers have certain limitations, such as complicated synthesis procedure, including high-temperature requirement, causing environmental pollution. In this work, a novel approach has been proposed for the production of high-purity potash fertilizer (KNO3, K2SO4, and KH2PO4) from KCl by metathesis electrodialysis (MED). Sulfonated poly(ether sulfone)-based cation-exchange membrane and quaternized brominated poly(2,6-dimethyl-1,4-phenylene oxide)-based anion-exchange membranes are used for the MED experiments. The membranes show adequate water uptake, ionic conductivity, and ion-exchange capacity with good mechanical and thermal stabilities. The yields of KNO3, K2SO4, and KH2PO4 are found to be 90, 86, and 90%, respectively. The power consumptions during MED experiment for KNO3, K2SO4, and KH2PO4 are calculated to 0.94, 0.89, and 1.04 kWh/kg, respectively. The purity of products is confirmed by inductively coupled plasma and X-ray diffraction analysis and by measuring ionic contents. The process provides an energy-intensive way for high-purity synthesis of KNO3, K2SO4, and KH2PO4.