Graphene bentonite supported ZnFe2O4 as superparamagnetic photocatalyst for antibiotic degradation 

¹School of Chemistry, Shoolini University of Biotechnology and Management Sciences,  Solan -173212, Himachal Pradesh, India

²School of Physics, Shoolini University of Biotechnology and Management Sciences,  Solan -173212, Himachal Pradesh, India

Adv. Mater. Lett., 2017, 8 (3), pp 229-238

DOI: 10.5185/amlett.2017.1467

Publication Date (Web): Jan 28, 2017

Copyright © IAAM-VBRI Press

E-mail: pardeepchem@gmail.com

Abstract

The supported photocatalysis is emerging as an effective technology to overcome of inherent drawbacks of bare magnetic photocatalysts. Herein, ZnFe₂O₄ was immobilized over graphene sand composite (GSC) and bentonite (BT) to report ZnFe₂O₄/GSC and ZnFe₂O₄/BT photocatalyst. The size of ZnFe₂O₄/GSC and ZnFe₂O₄/BT was obtained as 100 and 50 nm, respectively. Both photocatalysts exhibited band gap of 1.95 eV.  ZnFe₂O₄/GSC and ZnFe₂O₄/BT had BET surface area of 15.6 and 14.5 cm², respectively. The appearance of D and G band in Raman spectra indicated the formation of graphene sand composites. The superparamagnetic property of photocatalyst resulted in quick separation photocatalyst form reaction solution. The adsorption and photocatalytic capability of ZnFe₂O₄/GSC and ZnFe₂O₄/BT was evaluated for photo-mineralization of ampicillin and oxytetracycline antibiotics. The adsorption process showed significant effect on mineralization of selected antibiotics. Simultaneous adsorption and degradation (A+P) process was highly effective for antibiotic degradation. More than 90% of antibiotic mineralization was obtained in 10 hours. The power law model authorized the complex nature of degradation process. Magnetically recoverable photocatalyst exhibited significant recycling efficiency due to easier recovery of photocatalysts. 

Keywords

Superparamagnetic ZnFe₂O₄, supported-photocatalysis, antibiotic mineralization, kinetics.