2016年
Design of nitrogen-doped layered tantalates for non-sacrificial and selective hydrogen evolution from water under visible light
JOURNAL OF MATERIALS CHEMISTRY A
- ,
- ,
- ,
- 巻
- 4
- 号
- 37
- 開始ページ
- 14444
- 終了ページ
- 14452
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1039/c6ta04416f
- 出版者・発行元
- ROYAL SOC CHEMISTRY
Nitrogen doping into a series of layered tantalates (ALaTa(2)O(7), where A = Li, Na, K, Rb, or Cs) was attempted in order to produce materials capable of catalyzing non-sacrificial and endergonic water reduction under visible light. Heating of KLaTa2O7 and RbLaTa2O7 in an NH3 stream at 1073 K led to successful nitrogen doping, accompanied by a significant shift in the absorption edge of the material toward the visible-light region, while similar treatment of the other tantalates resulted in the collapse of the layered structure or partial anion substitution at the surface. Although the NH3 heating of a conventional RbLaTa2O7 precursor prepared with nearly stoichiometric Rb (Rb/La = 1.2) resulted in the formation of impurities such as Ta3N5 and amorphous tantalum nitrides, the use of a Rb-rich precursor prepared with excess Rb (Rb/La = 2.4) effectively suppressed this impurity formation. The Rb+ cations in the prepared pure nitrogen-doped sample were exchanged with H+ to facilitate the intercalation of water, and a cationic Pt precursor was then selectively introduced into the interlayers and photocatalytically reduced to Pt metal particles. The internally platinized H+/RbLaTa2O7-xNy showed stable H-2 evolution in the presence of I- as an electron donor under visible light, accompanied by the generation of I-3(-). Although the externally platinized H+/RbLaTa2O7-xNy sample and other bulk-type photocatalysts such as Ta3N5 generated H-2 in the presence of a sacrificial electron donor, H-2 evolution was negligible in the presence of I-. The stable H-2 evolution over the internally platinized H+/RbLaTa2O7-xNy sample is due to the suppressed backward reduction of I-3(-) to I- at selective reduction sites in the interlayer spaces, which are accessible only to cationic species and water.
- リンク情報
- ID情報
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- DOI : 10.1039/c6ta04416f
- ISSN : 2050-7488
- eISSN : 2050-7496
- ORCIDのPut Code : 52756764
- Web of Science ID : WOS:000384444200044