title: Synthesis and characterization of polyacrylic acid- grafted-carboxylic graphene/titanium nanotube composite for the effective removal of enrofloxacin from aqueous solutions: Adsorption and photocatalytic degradation studies.
abstract: Polyacrylic acid-grafted-carboxylic graphene/titanium nanotube (PAA-g-CGR/TNT) composite was synthesized. It was effectively used as adsorbent as well as photocatalyst. The composite was characterized by FTIR, XRD, SEM, TEM, Surface Area Analyzer, XPS and DRS. The photocatalytic activity of PAA-g-CGR/TNT composite was evaluated on the basis of the degradation of pollutants by using sunlight. The band gap of the prepared photocatalyst was found to be 2.6eV. The removal of the antibiotic enrofloxacin (ENR) was achieved by two step mechanism based on adsorption and photodegradation. The maximum adsorption was observed at pH 5.0. The best fitted kinetic model was found to be pseudo-second-order. The maximum adsorption was observed at 30°C. The maximum adsorption capacity was found to be 13.40mg/g. The kinetics of photodegradation of ENR onto PAA-g-CGR/TNT composite follow first-order kinetics and optimum pH was found to be 5.0. The regeneration and reuse of the adsorbent-cum-photocatalyst were also examined upto five cycles.
authors.affiliation: Department of Chemistry, School of Physical and Mathematical Sciences, University of Kerala, Kariavattom, Trivandrum 695 581, India. Electronic address: tsani@rediffmail.com.
authors.forename: Thayyath S
authors.initials: TS
authors.lastname: Anirudhan
authors.affiliation: Department of Chemistry, School of Physical and Mathematical Sciences, University of Kerala, Kariavattom, Trivandrum 695 581, India.
authors.forename: F
authors.initials: F
authors.lastname: Shainy
authors.affiliation: Department of Chemistry, School of Physical and Mathematical Sciences, University of Kerala, Kariavattom, Trivandrum 695 581, India.
authors.forename: J
authors.initials: J
authors.lastname: Christa
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry* / Q000528:radiation effects; D000327:Adsorption; D000970:Antineoplastic Agents / Q000737:chemistry*; D002384:Catalysis; D000077422:Enrofloxacin; D024841:Fluoroquinolones / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry* / Q000528:radiation effects; D006863:Hydrogen-Ion Concentration; D008027:Light; D046529:Microscopy, Electron, Transmission; D043942:Nanotubes / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure; D010782:Photolysis; D055672:Static Electricity; D014025:Titanium / Q000737:chemistry* / Q000528:radiation effects; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D000180:Acrylic Resins; D000970:Antineoplastic Agents; D024841:Fluoroquinolones; D014874:Water Pollutants, Chemical; D000077422:Enrofloxacin; C006903:carbopol 940; D006108:Graphite; D014025:Titanium
keywords: Adsorption; Enrofloxacin; Graphene oxide; Photocatalytic degradation; Titanium nanotubes