WO3 and W2N nanowire arrays for photoelectrochemical hydrogen production
| Autor: | Mahendra K. Sunkara, Vidhya Chakrapani, Jyothish Thangala |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Materials science
Absorption spectroscopy Renewable Energy Sustainability and the Environment Band gap business.industry Energy conversion efficiency Nanowire Energy Engineering and Power Technology Nanotechnology Condensed Matter Physics chemistry.chemical_compound Fuel Technology chemistry Electrode Optoelectronics Quantum efficiency business Tungsten nitride Hydrogen production |
| Zdroj: | International Journal of Hydrogen Energy. 34:9050-9059 |
| ISSN: | 0360-3199 |
| DOI: | 10.1016/j.ijhydene.2009.09.031 |
| Popis: | Tungsten oxide (WO 3 ) nanowire array samples were nitrided in a NH 3 atmosphere to get complete conversion to tungsten nitride (W 2 N) nanowires. UV–vis absorption spectroscopy shows that the band gap of WO 3 reduced from 2.9 eV to 2.2 eV after nitridation to W 2 N. Photoelectrochemical properties of both WO 3 and W 2 N nanowire array electrodes were investigated. WO 3 nanowire arrays show maximum incident photon-to-current conversion efficiency of 85% at 370 nm at 1.2 V vs. SCE. The high quantum efficiency is attributed to the nanowire architecture which ensures efficient light absorption and charge transport. The nanowire arrays were stable even up to 8 h of continuous gas evolution. W 2 N nanowire arrays showed good photoactivity even at moderate bias. However, the pure W 2 N electrodes were unstable with respect to photocorrosion. The mixed phase W 2 N–WO 3 nanowires showed improvement in stability compared to pure W 2 N nanowire arrays. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect