Fig. 5From: Preparation of Graphene Oxide-Based Hydrogels as Efficient Dye Adsorbents for Wastewater TreatmentSurvey XPS spectra (a) of samples: a, GO sheet; b, GO/PEI hydrogel (#2). Deconvolution of XPS peaks of the GO/PEI hydrogel (#2) nanocomposite: b C(1s), c N(1s), and d O(1s)Back to article page