TY - JOUR
T1 - Surface modified carbon nanomats provide cationic and anionic rectifier membranes in aqueous electrolyte media
AU - Tshwenya, Luthando
AU - Putra, Budi Riza
AU - Orimolade, Benjamin O.
AU - Marken, Frank
AU - Arotiba, Omotayo A.
N1 - Publisher Copyright:
© 2020
PY - 2020/9/10
Y1 - 2020/9/10
N2 - 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.
AB - 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.
KW - Carbon nanomat
KW - Dendrimer
KW - Desalination
KW - Ionic current rectification
KW - Ionic diode
KW - Surface modified carbon nanofibers
UR - http://www.scopus.com/inward/record.url?scp=85087949917&partnerID=8YFLogxK
U2 - 10.1016/j.electacta.2020.136750
DO - 10.1016/j.electacta.2020.136750
M3 - Article
AN - SCOPUS:85087949917
SN - 0013-4686
VL - 354
JO - Electrochimica Acta
JF - Electrochimica Acta
M1 - 136750
ER -