Surface modified carbon nanomats provide cationic and anionic rectifier membranes in aqueous electrolyte media. (10th September 2020)

• Record Type: Journal Article
• Authors: Tshwenya, Luthando; Putra, Budi Riza; Orimolade, Benjamin O.; Marken, Frank; Arotiba, Omotayo A.
• Is Part Of: Electrochimica acta. Volume 354(2020)
• Publication Date: 2020-09-10
• Subjects: Surface modified carbon nanofibers -- Carbon nanomat -- Ionic current rectification -- Ionic diode -- Dendrimer -- Desalination; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2020.136750
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: Carbon nanofibers (CNFs) are converted into anionic current rectifiers by surface modification with amine functional groups using hydrothermal means (forming modified CNFs, with generation-3 poly (propylene imine) dendrimer, urea and boric acid). To confirm surface charge, morphological changes and carbon nanomat thickness, zeta potential analysis, transmission electron microscopy (TEM) and scanning electron microscopy (SEM), were used. When a dispersion of surface modified carbon nanofibers in DMF is drop-cast asymmetrically to form nanomats onto laser drilled microholes (5, 10, or 20 µm diameter) of poly (ethylene terephthalate) substrates and immersed into aqueous electrolyte solutions, anionic diode behaviour is observed (in contrast to pristine carbon nanofibers, which exhibit cationic diode behaviour). The effects of electrolyte type, ionic strength, and microhole diameter on ionic diode performance were investigated using cyclic voltammetry, chronoamperometry, and impedance spectroscopy. Future applications in desalination are proposed. Graphical abstract: Image, graphical abstract