| 研究課題/領域番号 |
22F22366
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| 配分区分 | 補助金 |
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| 研究機関 | 国立研究開発法人物質・材料研究機構 |
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研究代表者 |
押切 光丈 国立研究開発法人物質・材料研究機構, 国際ナノアーキテクトニクス研究拠点, 主幹研究員 (20354368)
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| 研究分担者 |
LI SIJIE 国立研究開発法人物質・材料研究機構, 国際ナノアーキテクトニクス研究拠点, 外国人特別研究員
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| 研究期間 (年度) |
2022-11-16 – 2025-03-31
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| キーワード | photoelectrocatalysis / carbon dioxide reduction / silicon photocathode / photoanode / cocatalysts / surface and interface |
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| 研究実績の概要 |
This project aims at developing Si-based photocathodes and potential photoanodes for solar-driven synergistic reaction of CO2 reduction and water oxidation. In the past year, we converted planner p-Si semiconductors into p-Si pyramid-textured semiconductors as photocathodes by a liquid-phase etching method. The large specific surface area of p-Si pyramid-structure is conducive to the loading of cocatalysts and facilitates the separation and migration of photogenerated carriers. The photocathode performance was evaluated after loading cocatalyst. Compared with planner p-Si, the photoelectrochemical (PEC) CO2 reduction performance of p-Si pyramid was significantly improved, which proves that the PEC CO2 reduction performance of Si-based photocathodes is closely related to the semiconductor surface structure and the interface connection of semiconductor/cocatalyst.
On the other hand, we also tried to form transition metal oxide BiVO4 semiconductors on transparent conductive substrate (fluorine-doped tin oxide: FTO) based on a liquid-phase synthesis strategy. It was confirmed that BiOI was electrodeposited on the substrate first, and then transformed into BiVO4 semiconductors by heat treatment. The chemical composition, morphology, and crystal structure of BiVO4 semiconductor with porous nanostructure were analyzed and evaluated. Since the as-prepared BiVO4 porous nanostructured semiconductor exhibits n-type semiconducting properties, we set out to try to optimize it as a potential photoanode for assisting PEC CO2 reduction.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
Focusing on the proposed research plan, we have constructed Si nanostructures as photocathodes for PEC CO2 reduction. Current results indicated that the surface modification of Si semiconductors is beneficial to the loading of cocatalysts in the later stage and exhibits better PEC catalytic performance. In addition, we analyzed the morphology, chemical composition, and crystal structure of the as-prepared BiVO4 porous nanostructured semiconductor, confirming that it is a strong candidate for the desired n-type semiconductor photoanode. In the water oxidation performance test, the BiVO4 photoanode also showed gratifying performance. Therefore, we have made smooth progress in fabricating the Si-based semiconductor photocathode and its potential photoanode, which provides a good foundation for subsequently constructing the synergistic reaction device of CO2 reduction and water oxidation.
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| 今後の研究の推進方策 |
On the basis of the previous year's research, future research will mainly focus on three issues. First, we will continue to systematically study and optimize the surface structure of Si-based semiconductor photocathode to further improve the separation and migration of photogenerated carriers. Second, we will design and optimize CO2 reduction cocatalysts to achieve a superior adhesion at the cocatalyst/Si semiconductor interface, thereby constructing a Si-based photocathode system with low onset potential and high photocurrent. The third is the further structure improvement and performance evaluation of the n-type BiVO4 photoanode to help to achieve unbiased CO2 reduction.
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