Synergy of TiO2/Na0.23TiO2 Heterojunction for Enhanced Photocatalysis. Issue 8 (13th July 2018)

• Record Type: Journal Article
• Authors: Wang, Jing‐Zhou; Zhou, Jian‐Ping; Guo, Ze‐Qing; Lei, Yu‐Xi; Hassan, Qadeer Ul
• Is Part Of: Crystal research and technology. Volume 53:Issue 8(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-07-13
• Subjects: band gap -- Fermi level -- hydrothermal methods -- mid‐gap state -- photocatalytic activity; Crystallography -- Periodicals; 548
• DOI: 10.1002/crat.201700153
• Languages: English
• ISSNs: 0232-1300

Abstract

Abstract: TiO2 /Na0.23 TiO2 composite photocatalyst is prepared by a simple hydrothermal method. Na0.23 TiO2 appears at the alkali concentration of 1.2 m, 320 °C, and 80 min. Different morphologies are obtained under different experimental conditions—namely, nanosheets, nanowire, and nanorod. The photocatalytic activity of TiO2 /Na0.23 TiO2 composites is superior to the raw anatase titanium dioxide (TiO2 ) for the degradation of methylene blue under UV–visible light irradiation. The best photocatalytic performance is achieved in a composite prepared at an alkali concentration of 1.5 m . The photogenerated charge separation is a main factor in enhancing the activity of semiconductor‐based photocatalysts. The calculated band gap of Na0.23 TiO2 is about 2.904 eV. The Fermi level lies in the conduction band in Na0.23 TiO2 while it is near the valence band in anatase TiO2 . Then, a heterojunction is formed and is helpful for the photogenerated electron‐hole pairs separation, resulting in an enhanced photocatalysis. Abstract : TiO2 /Na0.23 TiO2 photocatalyst is synthesized by a hydrothermal method for the first time. TiO2 /Na0.23 TiO2 composite exhibits superior photocatalytic activity to anatase titanium dioxide for the degradation of methylene blue under UV–visible light irradiation. Heterojunction is helpful for the photogenerated electron‐hole pairs separation, resulting in an enhanced photocatalysis. The authors propose a photocatalytic mechanism on the basis of theoretical calculation.