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Zhang Z, Tsuchimochi T, Ina T, Kumabe Y, Muto S, Ohara K, Yamada H, Ten-No SL, Tachikawa T. Binary dopant segregation enables hematite-based heterostructures for highly efficient solar H 2O 2 synthesis. Nat Commun 2022; 13:1499. [PMID: 35322014 PMCID: PMC8943161 DOI: 10.1038/s41467-022-28944-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 02/14/2022] [Indexed: 12/25/2022] Open
Abstract
Dopant segregation, frequently observed in ionic oxides, is useful for engineering materials and devices. However, due to the poor driving force for ion migration and/or the presence of substantial grain boundaries, dopants are mostly confined within a nanoscale region. Herein, we demonstrate that core–shell heterostructures are formed by oriented self-segregation using one-step thermal annealing of metal-doped hematite mesocrystals at relatively low temperatures in air. The sintering of highly ordered interfaces between the nanocrystal subunits inside the mesocrystal eliminates grain boundaries, leaving numerous oxygen vacancies in the bulk. This results in the efficient segregation of dopants (~90%) on the external surface, which forms their oxide overlayers. The optimized photoanode based on hematite mesocrystals with oxide overlayers containing Sn and Ti dopants realises high activity (~0.8 μmol min−1 cm−2) and selectivity (~90%) for photoelectrochemical H2O2 production, which provides a wide range of application for the proposed concept. Photoelectrochemical H2O2 production offers a renewable means for chemical synthesis, yet water oxidation to H2O2 remains a challenge. Here, authors prepare heterostructured, metal-doped hematite mesocrystals that show a high selectivity for photoelectrochemical H2O2 alongside H2 production.
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Affiliation(s)
- Zhujun Zhang
- Molecular Photoscience Research Center, Kobe University, 1-1 Rokkodai-Cho, Nada-Ku, Kobe, 657-8501, Japan
| | - Takashi Tsuchimochi
- Graduate School of System Informatics, Kobe University, 1-1 Rokkodai-Cho, Nada-Ku, Kobe, 657-8501, Japan.,PRESTO, Japan Science and Technology Agency (JST), 4-1-8 Honcho Kawaguchi, Saitama, 332-0012, Japan
| | - Toshiaki Ina
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-Cho, Sayo-Gun, Hyogo, 679-5198, Japan
| | - Yoshitaka Kumabe
- Molecular Photoscience Research Center, Kobe University, 1-1 Rokkodai-Cho, Nada-Ku, Kobe, 657-8501, Japan
| | - Shunsuke Muto
- Electron Nanoscopy Section, Advanced Measurement Technology Center, Institute of Materials and Systems for Sustainability, Nagoya University, Furo-Cho, Chikusa-Ku, Nagoya, 464-8603, Japan
| | - Koji Ohara
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-Cho, Sayo-Gun, Hyogo, 679-5198, Japan
| | - Hiroki Yamada
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-Cho, Sayo-Gun, Hyogo, 679-5198, Japan
| | - Seiichiro L Ten-No
- Graduate School of System Informatics, Kobe University, 1-1 Rokkodai-Cho, Nada-Ku, Kobe, 657-8501, Japan.,Graduate School of Science, Technology, and Innovation, Kobe University, 1-1 Rokkodai-Cho, Nada-Ku, Kobe, 657-8501, Japan
| | - Takashi Tachikawa
- Molecular Photoscience Research Center, Kobe University, 1-1 Rokkodai-Cho, Nada-Ku, Kobe, 657-8501, Japan. .,Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-Cho, Nada-Ku, Kobe, 657-8501, Japan.
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Ansari MJ, Jasim SA, Taban TZ, Bokov DO, Shalaby MN, Al-Gazally ME, Kzar HH, Qasim MT, Mustafa YF, Khatami M. Anticancer Drug-Loading Capacity of Green Synthesized Porous Magnetic Iron Nanocarrier and Cytotoxic Effects Against Human Cancer Cell Line. J CLUST SCI 2022. [DOI: 10.1007/s10876-022-02235-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Ansari MJ, Jasim SA, Taban TZ, Bokov DO, Shalaby MN, Al-Gazally ME, Kzar HH, Qasim MT, Mustafa YF, Khatami M. Anticancer Drug-Loading Capacity of Green Synthesized Porous Magnetic Iron Nanocarrier and Cytotoxic Effects Against Human Cancer Cell Line. J CLUST SCI 2022. [DOI: https://doi.org/10.1007/s10876-022-02235-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Serrano A, López-sánchez J, Arnay I, Cid R, Vila M, Salas-cólera E, Castro GR, Rubio-zuazo J. Improving the CO and CH4 Gas Sensor Response at Room Temperature of α-Fe2O3(0001) Epitaxial Thin Films Grown on SrTiO3(111) Incorporating Au(111) Islands. Coatings 2021; 11:848. [DOI: 10.3390/coatings11070848] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In this work, the functional character of complex α-Fe2O3(0001)/SrTiO3(111) and Au(111) islands/α-Fe2O3(0001)/SrTiO3(111) heterostructures has been proven as gas sensors at room temperature. Epitaxial Au islands and α-Fe2O3 thin film are grown by pulsed laser deposition on SrTiO3(111) substrates. Intrinsic parameters such as the composition, particle size and epitaxial character are investigated for their influence on the gas sensing response. Both Au and α-Fe2O3 layer show an island-type growth with an average particle size of 40 and 62 nm, respectively. The epitaxial and incommensurate growth is evidenced, confirming a rotation of 30° between the in-plane crystallographic axes of α-Fe2O3(0001) structure and those of SrTiO3(111) substrate and between the in-plane crystallographic axes of Au(111) and those of α-Fe2O3(0001) structure. α-Fe2O3 is the only phase of iron oxide identified before and after its functionalization with Au nanoparticles. In addition, its structural characteristics are also preserved after Au deposition, with minor changes at short-range order. Conductance measurements of Au(111)/α-Fe2O3(0001)/SrTiO3(111) system show that the incorporation of epitaxial Au islands on top of the α-Fe2O3(0001) layer induces an enhancement of the gas-sensing activity of around 25% under CO and 35% under CH4 gas exposure, in comparison to a bare α-Fe2O3(0001) layer grown on SrTiO3(111) substrates. In addition, the response of the heterostructures to CO gas exposure is around 5–10% higher than to CH4 gas in each case.
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