Enhancing visible light photo-oxidation of water with TiO2 nanowire arrays via cotreatment with H2 and NH3: synergistic effects between Ti3+ and N

Son Hoang; Sean P Berglund; Nathan T Hahn; Allen J Bard; C Buddie Mullins

doi:10.1021/ja211369s

Enhancing visible light photo-oxidation of water with TiO2 nanowire arrays via cotreatment with H2 and NH3: synergistic effects between Ti3+ and N

J Am Chem Soc. 2012 Feb 29;134(8):3659-62. doi: 10.1021/ja211369s. Epub 2012 Feb 14.

Authors

Son Hoang¹, Sean P Berglund, Nathan T Hahn, Allen J Bard, C Buddie Mullins

Affiliation

¹ Department of Chemical Engineering, Center for Electrochemistry, Texas Materials Institute, University of Texas at Austin, 1 University Station C0400, Austin, Texas 78712-0231, USA.

PMID: 22316385
DOI: 10.1021/ja211369s

Abstract

We report a synergistic effect involving hydrogenation and nitridation cotreatment of TiO(2) nanowire (NW) arrays that improves the water photo-oxidation performance under visible light illumination. The visible light (>420 nm) photocurrent of the cotreated TiO(2) is 0.16 mA/cm(2) and accounts for 41% of the total photocurrent under simulated AM 1.5 G illumination. Electron paramagnetic resonance (EPR) spectroscopy reveals that the concentration of Ti(3+) species in the bulk of the TiO(2) following hydrogenation and nitridation cotreatment is significantly higher than that of the sample treated solely with ammonia. It is believed that the interaction between the N-dopant and Ti(3+) is the key to the extension of the active spectrum and the superior visible light water photo-oxidation activity of the hydrogenation and nitridation cotreated TiO(2) NW arrays.