Cation-Deficient Tantalum Oxide–Zinc Tantalate Nanocomposite for Photocatalytic Carbon Dioxide Conversion
- 1Kyoto University
- 2Sumitomo Metal Mining (Japan)
Abstract
Artificial photosynthesis offers a promising route to close the anthropogenic carbon cycle, yet efficient photocatalytic CO2 conversion with H2O as an electron donor remains challenging.ZnTa2O6 (ZTO0.50) is one of the most active photocatalysts, but the origin of its activity remains unclear.In this study, we show that Ta-rich ZnTa2O6 (ZTOn, n = Zn/Ta) inherently contains a rutile-type tantalum oxide phase, identified as cationdeficient Ta0.8O2, whose role has been largely overlooked.By tuning the ZnO/Ta2O5 precursor ratio, we obtain ZTO0.43 with the highest Ta0.8O2 content.Structural and spectroscopic analyses reveal atomically intimate interfaces between Ta0.8O2 and ZnTa2O6 that promote charge separation and H2O oxidation.Density functional theory calculations show that Ta vacancies stabilise a semiconducting electronic structure and induce wavefunction localisation on adjacent O atoms, enhancing their reactivity towards H2O oxidation.Consequently, ZTO0.43 modified with the Ag@Cr cocatalyst achieves a CO formation rate exceeding 1 mmol h -1 , with a 95% selectivity; to the best of our knowledge, this is the highest CO formation rate obtained via photocatalytic conversion of CO2 with H2O as the electron donor.
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BibTeX
@misc{kawata2026cationdeficient,
title = {{Cation-Deficient Tantalum Oxide–Zinc Tantalate Nanocomposite for Photocatalytic Carbon Dioxide Conversion}},
author = {Kio Kawata and Shoji Iguchi and Shimpei Naniwa and Akihisa Ishikawa and Wataru Ota and Tohru Sato and Masamu Nishimoto and Kentaro Teramura},
howpublished = {ChemRxiv},
year = {2026},
month = oct,
doi = {10.26434/chemrxiv-2025-8x01k/v3},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv-2025-8x01k/v3},
note = {CC BY},
}
RIS
TY - UNPB
TI - Cation-Deficient Tantalum Oxide–Zinc Tantalate Nanocomposite for Photocatalytic Carbon Dioxide Conversion
AU - Kio Kawata
AU - Shoji Iguchi
AU - Shimpei Naniwa
AU - Akihisa Ishikawa
AU - Wataru Ota
AU - Tohru Sato
AU - Masamu Nishimoto
AU - Kentaro Teramura
PY - 2026
DA - 2026/10/06
PB - ChemRxiv
DO - 10.26434/chemrxiv-2025-8x01k/v3
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv-2025-8x01k/v3
AB - Artificial photosynthesis offers a promising route to close the anthropogenic carbon cycle, yet efficient photocatalytic CO2 conversion with H2O as an electron donor remains challenging.ZnTa2O6 (ZTO0.50) is one of the most active photocatalysts, but the origin of its activity remains unclear.In this study, we show that Ta-rich ZnTa2O6 (ZTOn, n = Zn/Ta) inherently contains a rutile-type tantalum oxide phase, identified as cationdeficient Ta0.8O2, whose role has been largely overlooked.By tuning the ZnO/Ta2O5 precursor ratio, we obtain ZTO0.43 with the highest Ta0.8O2 content.Structural and spectroscopic analyses reveal atomically intimate interfaces between Ta0.8O2 and ZnTa2O6 that promote charge separation and H2O oxidation.Density functional theory calculations show that Ta vacancies stabilise a semiconducting electronic structure and induce wavefunction localisation on adjacent O atoms, enhancing their reactivity towards H2O oxidation.Consequently, ZTO0.43 modified with the Ag@Cr cocatalyst achieves a CO formation rate exceeding 1 mmol h -1 , with a 95% selectivity; to the best of our knowledge, this is the highest CO formation rate obtained via photocatalytic conversion of CO2 with H2O as the electron donor.
ER -