AUTHOR=Qi Guangfeng , Wang Xiaohui , Zhao Jingang , Song Chunyan , Zhang Yanbo , Ren Feizhou , Zhang Nan 

TITLE=Fabrication and Characterization of the Porous Ti4O7 Reactive Electrochemical Membrane

JOURNAL=Frontiers in Chemistry

VOLUME=Volume 9 - 2021

YEAR=2022

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2021.833024

DOI=10.3389/fchem.2021.833024

ISSN=2296-2646

ABSTRACT=Preparation of the Magnéli Ti4O7 reactive electrochemical membrane (REM) with high purity is of great significance for its application in electrochemical advanced oxidation processes (EAOPs) for wastewater treatment. In this study, Ti4O7 REM with high purity was synthesized by mechanical pressing of TiO2 powders followed by thermal reduction to Ti4O7 using Ti powder as the reducing reagent, where the TiO2 monolith and Ti powder were separated from each other with the distance of about 5 cm in the vacuum furnace. When the temperature was elevated to 1333 K, Magnéli phase Ti4O7 REM with the Ti4O7 content of 98.5% was obtained after 4 h’s thermal reduction. Noticeably, the surface and interior of obtained REM bulk sample has homogeneous Ti4O7 content. Doping carbon black (0wt%-15wt%) could increase the porosity of the Ti4O7 REM (38%-59%). Accordingly, the internal resistance of electrode and electrolyte and the charge-transfer impedance increased slightly with increasing carbon black content. The optimum electro-active surface area (1.1 m2) was obtained at carbon black content of 5wt%, which increased by 1.3-fold in comparison with that without carbon black. The as-prepared Ti4O7 REMs shows high oxygen evolution potential, approximately 2.7 V/SHE, indicating their appreciable electrocatalytic activity toward the production of •OH.