Removal of toxic Cr(vi) by UV-active functionalized graphene oxide for water purification

Abstract

Extraction of hazardous heavy metals like As, Hg, Cd, Cr(VI), etc. for water purification is a great challenge. Exploiting the large surface area of graphene, in the present work, we have synthesized a UV-active 2,6-diamino pyridine-reduced graphene oxide (DAP-RGO) composite to remove Cr(VI) from acidic water solution. Here, the presence of an extra pyridinic-nitrogen lone pair facilitates the removal efficiency of excess Cr(VI) [500 mg L À1 in 3 h only] over reported results so far. In addition to that, the unique advantage of this UV-active material is the enhancement of removal efficiency by 18% at a higher pH value. We believe that this study will bring forth a new class of UV-active graphene based adsorbents with remarkably high removal efficiency for toxic heavy metals from waste-water in future.

1‐Aza‐15‐Crown‐5 Functionalized Graphene Oxide for 2D Graphene‐Based Li+‐ion Conductor

“…Such shifting of binding energy of G band has also been reported in some surface-functionalized graphitic materials. [ 25,26 ] After Li + -ion attachment, the G band is blue shifted to 1602 cm −1 and this type of blue shifting arises due to the interaction of Li + ion with the composite structure. [ 27 ] To understand the proper interaction between the Li ions and the graphitic C atoms, we have analyzed the XPS spectra of the composite shown in Figure 2 .…”

“…[ 31 ] The highest binding energy peak at ≈288.4 eV corresponds to the binding energy of carboxylic group. [ 26 ] To understand the chemical nature of Li in the composite is of great importance as it may provide useful information about the interactions between the Li + ions and the graphitic C atoms. Figure 2 c represents the high-resolution Li 1s XPS spectrum, which has been fi tted by three components.…”

Modification of mesoporous silica magnetite nanoparticles by 3-aminopropyltriethoxysilane for the removal of Cr(VI) from aqueous solution

“…The unite cell parameter (a 0 ) could be calculated from d 100 value by the following equation. and then its absorbance is measured by UV-Vis spectrophotometer at 540 nm [4,26].…”

“…Despite these positive features, MNPs are M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 4 associated with several deficiencies such as aggregation, oxidation in air and instability under acidic conditions. For reduction of these undesirable features, bare MNPs are embedded into a host matrix [12].…”

“…Cr (III) is considered as a necessary element for controllingof glucose, lipid and protein metabolism in the human and animal body. While Cr (VI) is very dangerous to living organism due to its toxicity, mutagenic and carcinogenic properties [4,5].…”