Highly porous Ti4O7 reactive electrochemical water filtration membranes fabricated via electrospinning/electrospraying

Abstract

Porous, flexible, reactive electrochemical membranes (REMs) for water purification were synthesized by a novel simultaneous electrospinning/electrospraying (E/E) technique, which produced a network of poly(sulfone) fibers and Ti4O7 particles as evidenced by scanning electron microscopy. Cyclic voltammetry indicated that the kinetics for water electrolysis reactions and the Fe(CN)(6)(4-/3-) redox couple were enhanced by Ti4O7 deposition using the E/E technique. Membrane filtration experiments using phenol as a model contaminant showed a 2.6-fold enhancement in the observed first-order rate constant for phenol oxidation (k(obs,phenol)) in filtration mode relative to cross-flow operation. Phenol oxidation in filtration mode was approaching the pore diffusion mass transfer limit, and was 6 to 8 times higher than measured in a previous study that utilized a ceramic Ti4O7 REM operated in filtration mode and is comparable to rate constants obtained with carbon nanotube flow-through reactors, which are among the highest reported in the literature to date. (c) 2015 American Institute of Chemical Engineers AIChE J, 62: 508-524, 2016