Thursday, 17 May 2018: 08:15
Room 612 (Washington State Convention Center)
The use of TiO2 photoelectrodes (or TiO2 suspensions) to produce hydrogen from various electrolytes (with or without sacrificial agents) has been highly investigated over the past decades and still remains a most investigated topic.1 The advantage of anodic TiO2 nanotubes (NTs) is not only that they provide a one dimensional charge-transfer path, but also they are back-contacted on metal substrate that can be used as electrodes directly.2 Pathways to create noble-metal-free H2 evolution activity on TiO2 NTs are not only of considerable scientific but also of high economic interest.3-4 Here we introduce an efficient way to introduce a sub-surface configuration of a broad range of lattice defects (namely vacancy/interstitial pairs) using high energy ion implantation.5
In this study, we report defect containing TiO2 NTs that strongly acts as photo co-catalysts. This catalyst is obtained by low-dose nitrogen ion-implantation that can be tuned to obtain a highly defined ion and defect distribution within the TiO2 NT substrate. A particular advantage of creating these defect centers by N-implantation is that the active centers can be placed as a coherent layer at a defined sub-surface location and allow surface patterning.6 The catalysts presented here show considerable photocatalytic activity for hydrogen evolution under solar light illumination in the absence of noble metal or external bias. These results provide a new platform for TiO2 based photo co-catalysts.
References
- Fujishima and K. Honda, Nature, 1972, 238, 37-38.
- X. Zhou, N. T. Nguyen, S. Özkan, P. Schmuki, Electrochem. Comm., 2014(46,) 157–162.
- Zhou, N. Liu and P. Schmuki, Electrochem. Commun., 2014 (49), 60–64.
- N Liu, V. Häublein, X. Zhou, U. Venkatesan, M. Hartmann, M. Mačković, T. Nakajima, E. Spiecker, A. Osvet, L. Frey, and P. Schmuki, Nano Lett., 2015, 15 (10), 6815–6820.
- Zhou, V. Häublein, N. Liu, N. T. Nguyen, E. M. Zolnhofer, H. Tsuchiya, M. S. Killian, K. Meyer, L. Frey, P. Schmuki, Angew. Chem. Int. Ed. 2016, 55, 3763-3767.
- X. Zhou, N. Liu, P. Schmuki, ACS Cat., 2017, 7, 3210–3235.