title: Optimized graphene oxide foam with enhanced performance and high selectivity for mercury removal from water.
abstract: This work explores the preparation of three-dimensional graphene oxide macroscopic structures, shaped by self-assembling single graphene oxide (3DGO) sheets with control of its surface chemistry by combining with nitrogen functional groups (3DGON), or with nitrogen and sulphur functional groups (3DGOSN), and their application in the removal of mercury (Hg(II)) from aqueous solutions. The chemical structure of the materials was assessed by using different characterization techniques: SEM, XPS and BET. Adsorption studies conducted in Hg(II) contaminated ultra-pure water reveal the enhanced ability of 3DGON for the adsorption of this metal, when compared to the other GO foams. A small dose of 3DGON (10 mg L(-1)) allows to remove up to 96% of Hg(II) after 24 h of contact time, leading to a residual concentration in solution close to the guideline value for drinking water (1 μg L(-1)). The ability of this material to adsorb Hg (II) was evaluated relatively to different experimental parameters such as pH, sorbent dose, time and effect on different competing metal ions. Real application was also evaluated by testing its performance in two different natural matrices, river and sea water, with very promising results.
authors.affiliation: CESAM & Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: Bruno
authors.initials: B
authors.lastname: Henriques
authors.affiliation: TEMA-NRD, Mechanical Engineering Department, University of Aveiro, 3810-193 Aveiro, Portugal; Aveiro Institute of Nanotechnology, AIN, University of Aveiro, 3810-193 Aveiro, Portugal. Electronic address: ggoncalves@ua.pt.
authors.forename: Gil
authors.initials: G
authors.lastname: Gonçalves
authors.affiliation: Department of Applied Physics and Mechanical Eng., Lulea University of Technology, Sweden.
authors.forename: Nazanin
authors.initials: N
authors.lastname: Emami
authors.affiliation: CESAM & Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: Eduarda
authors.initials: E
authors.lastname: Pereira
authors.affiliation: TEMA-NRD, Mechanical Engineering Department, University of Aveiro, 3810-193 Aveiro, Portugal; Aveiro Institute of Nanotechnology, AIN, University of Aveiro, 3810-193 Aveiro, Portugal; Centro de Investigación Biomédica en Red. Bioingeniería, Biomateriales y Nanomedicina, CIBER-BBN, Spain. Electronic address: mvila@ua.pt.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Vila
authors.affiliation: TEMA-NRD, Mechanical Engineering Department, University of Aveiro, 3810-193 Aveiro, Portugal; Aveiro Institute of Nanotechnology, AIN, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: Paula A A P
authors.initials: PA
authors.lastname: Marques
keywords: Competitive ions; Graphene oxide; Mercury; Natural waters; Remediation; Sorption