Hierarchically porous monoliths based on N-Doped reduced titanium oxides and their electric and electrochemical properties

Year: 2013 DOI: 10.1021/cm401933a

Extra Information

George Hasegawa, Tatsuya Sato, Kazuyoshi Kanamori, Kousuke Nakano, Takeshi Yajima, Yoji Kobayashi, Hiroshi Kageyama, Takeshi Abe, Kazuki Nakanishi.   Chemistry of Materials, 2013, 25, 3504-3512.

Abstract

In this report, we demonstrate a novel synthesis method to obtain reduced titanium oxides with monolithic shape and with a well-defined hierarchically porous structure from the titanium-based network bridged with ethylenediamine. The hierarchically porous monoliths are fabricated by the nonhydrolytic sol?gel reaction accompanied by phase separation. This method allows a low-temperature crystallization into Ti4O7 and Ti3O5 at 800 and 900 °C, respectively, with N-doped carbon. These reduced titanium oxides are well-doped with N atoms even under argon atmosphere without NH3, which accounts for the low-temperature reduction. The resultant monolithic materials possess controllable macropores and high specific surface area together with excellent electric conductivity up to 230 S cm?1, indicating promise as a conductive substrate that can substitute carbon electrodes. In this report, we demonstrate a novel synthesis method to obtain reduced titanium oxides with monolithic shape and with a well-defined hierarchically porous structure from the titanium-based network bridged with ethylenediamine. The hierarchically porous monoliths are fabricated by the nonhydrolytic sol?gel reaction accompanied by phase separation. This method allows a low-temperature crystallization into Ti4O7 and Ti3O5 at 800 and 900 °C, respectively, with N-doped carbon. These reduced titanium oxides are well-doped with N atoms even under argon atmosphere without NH3, which accounts for the low-temperature reduction. The resultant monolithic materials possess controllable macropores and high specific surface area together with excellent electric conductivity up to 230 S cm?1, indicating promise as a conductive substrate that can substitute carbon electrodes.