Nano tin ferrous oxide decorated graphene oxide sheets for efficient arsenic (III) removal

Nano-sized tin ferrous oxide (Sn0.95Fe0.05O2−δ) decorated graphene oxide (GO) based adsorbents were synthesized by solution combustion technique. The synthesized adsorbents were thoroughly characterized by SEM, XRD, XPS, TGA, and BET with respect to their structure, morphology and specific surface area. A four-fold increase in the sorption capacity was realized in Sn0.95Fe0.05O2−δ decorated GO sheets compared to individual GO and nano tin ferrous oxide. The adsorption kinetics followed the pseudo-second-order model and the isotherm followed Langmuir equilibrium. The equilibrium isotherm showed that Sn0.95Fe0.05O2−δ decorated GO nanoparticles had higher sorption capacity (qm=105 mg g−1) compared to both Sn0.95Fe0.05O2−δ (qm=27 mg g−1) and GO (qm=23 mg g−1) indicating excellent synergism. The continuous adsorption of As (III) in a column was also conducted to investigate its feasibility for large-scale operations.