One-pot green synthesis of rGO-NiO/CdO nanocomposite materials for the photocatalytic degradation of phenol from waste waters and the study of resistance against Staphylococcus aureus

Abstract

Reduced graphene oxide (rGO) adorned NiO/CdO (rNC) nanocomposite is made through a simple one pot synthesis process by reducing graphene oxide obtained via the Hummer's method with Alternanthera sessilis leaf extract. An evaluation of the photocatalytic and antibacterial properties of the rNC composite was conducted in comparison to the results obtained for NiO/CdO (NC) nanocomposite prepared using chemical precipitation. XRD patterns of NC and rNC samples show peaks associated with cubic NiO and CdO. rNC composite images show spherical grains along with a few nanoneedles. NC and rNC composites exhibit optical band gaps of 2.96 and 2.82 eV, respectively. FTIR spectrum of the rNC composite revealed Cd-O and Ni-O bands at 757, 633, 489 cm−1. NC and rNC catalysts degraded 80.5% and 89.6% of phenol after 90 min of visible light irradiation. rGO shows strong electron conductivity and high adsorption capacity, which may account for increased photodegradation efficiency of rNC catalyst. Antibacterial efficacy of the NC composite improves with rGO decoration.

Keywords

• Green synthesis
• XRD
• Raman studies
• Photodegradation
• Reactive oxygen species