Corn husk multilayered graphene/ZnO nanocomposite materials with enhanced photocatalytic activity for organic dyes and doxycycline degradation

Abstract

This study focuses on utilization of biomass waste for fabrication of multilayered graphene (MLG) via cellulose extraction. MLG nanosheets were synthesized from corn husk via alkali-acid treatments, pyrolysis, and activation. Initially, cellulose was extracted followed by carbonization and activation of the carbon material. Multilayered graphene/zinc oxide (MLG/ZnO) nanocomposite was synthesized through ex-situ casting of ZnO and MLG nanopowders. The photocatalytic degradation of congo red (CR) and rhodamine B (RhB) by MLG/ZnO photocatalyst under sunlight irradiation exhibited maximum degradations of 100 and 86%, respectively, while pristine ZnO gave degradations of 85 and 71% for RhB and CR, respectively. The obtained results validated high photocatalytic activity for the optimized MLG/ZnO nanocomposite in RhB and CR degradation under natural sunlight irradiation. The nanocomposite further demonstrates 95% degradation for doxycycline (DOX) under UV light. This work provides an insight into better ways of recycling biomass waste to fabricate valuable materials to solve environmental problems.