title: Sulfuric acid doped poly diaminopyridine/graphene composite to remove high concentration of toxic Cr(VI).
abstract: Sulfuric acid doped diaminopyridine polymers are synthesized in situ on graphene oxide surface via mutual oxidation-reduction technique. Exploiting large and highly porous surface, we have used this polymer composite as an adsorbent to remove high concentration of toxic Cr(VI) from water. It shows very high adsorption capacity (609.76 mg g(-1)) during removal process. The composite takes only 100 min to remove high concentration of 500 mg L(-1) Cr(VI) from water. Interesting features for this material is the enhancement of removal efficiency at lower acidic condition due to the formation of acid doped emeraldine salt during polymerization. XPS and AAS measurements reveal that our prepared material mainly follows reduction mechanism at higher acidic condition while anions exchange mechanism at lower acidic condition during the removal experiments. Good recycling ability with ∼ 92% removal efficiency after fifth cycle is also noticed for this material. Easy preparation, superior stability in acidic condition, remarkable removal efficiency and excellent recycling ability make this polymer composite an efficient material for modern filtration units in waste water purification.
authors.affiliation: Department of Materials Science, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India.
authors.forename: Diptiman
authors.initials: D
authors.lastname: Dinda
authors.affiliation: Department of Materials Science, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India. Electronic address: cnssks@iacs.res.in.
authors.forename: Shyamal
authors.initials: S
authors.lastname: Kumar Saha
mesh_terms: D000327:Adsorption; D002857:Chromium / Q000302:isolation & purification* / Q000633:toxicity; D006108:Graphite / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste / Q000032:analysis; D007700:Kinetics; D008855:Microscopy, Electron, Scanning; D011108:Polymers; D011725:Pyridines / Q000737:chemistry*; D013464:Sulfuric Acids / Q000737:chemistry*; D013633:Tanning; D013816:Thermodynamics; D014874:Water Pollutants, Chemical / Q000302:isolation & purification* / Q000633:toxicity; D018508:Water Purification / Q000379:methods*
chemical_list: D007220:Industrial Waste; D011108:Polymers; D011725:Pyridines; D013464:Sulfuric Acids; D014874:Water Pollutants, Chemical; D002857:Chromium; C074702:chromium hexavalent ion; D006108:Graphite; C505797:2,6-diaminopyridine; C033158:sulfuric acid
keywords: Graphene; High adsorption capacity and good recycling ability; In situ polymerization; Removal of toxic Cr(VI); Sulfuric acid doping