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 Ti 4 O 7 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 Ti 4 O 7 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 Ti 4 O 7 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. © 2015 American Institute of Chemical Engineers AIChE J , 62: 508–524, 2016