Fig. 2From: Facile synthesis of reduced graphene oxide by Tecoma stans extracts for efficient removal of Ni (II) from water: batch experiments and response surface methodology(a) UV–Vis spectroscopy and (b) FT-IR spectra of graphene oxide (GO), and reduced graphene oxide (rGO) using different concentrations of Tecoma stans leaves extract (5, 25, and 50 mg mL− 1 of leaves extract)Back to article page