単一粒子触媒上での水酸化反応を可視化(Scientists Visualize Water Oxidation on Single-Particle Catalysts)

2026-06-25 中国科学院(CAS)

中国科学院大連化学物理研究所の李燦教授、樊風涛教授らと厦門大学の研究チームは、オペランドSHINERS(殻絶縁ナノ粒子増強ラマン分光法)とナノスケール電気化学イメージングを組み合わせ、水分解における酸素発生反応(水酸化反応)の進行を単一粒子触媒上で原子レベルの空間分解能で可視化することに成功した。対象としたBiVO₄光触媒では、光照射で生成した正孔密度が0.67 nm⁻²を境に反応機構が変化することを明らかにした。閾値以下では(110)面と(010)面の双方で単一正孔移動が律速となり、OOHやOO中間体が形成される。一方、閾値を超えると(010)面では多正孔蓄積により反応速度が大幅に向上し、(110)面では高エネルギーを要する別経路へ移行することが判明した。これにより、水酸化反応は固定的な活性点ではなく、正孔蓄積に応じて触媒構造と反応経路が動的に再構成されることが示された。人工光合成触媒の設計を、静的な材料構造の最適化から光電荷と触媒構造の動的な相互作用の制御へ転換する新たな指針を提示した。

<関連情報>

単粒子触媒上での水酸化反応の空間イメージング Spatial imaging of water oxidation on single-particle catalysts

Wei Nie,Hong-Jia Wang,Yuying Gao,Deng Li,Yu Jin,Shisheng Zheng,Qian Li,Ziyuan Wang,Jian-Feng Li,Fengtao Fan & Can Li
Nature Nanotechnology  Published:12 June 2026
DOI:https://doi.org/10.1038/s41565-026-02184-3

単一粒子触媒上での水酸化反応を可視化(Scientists Visualize Water Oxidation on Single-Particle Catalysts)

Abstract

Water oxidation, widely recognized as the kinetic bottleneck of artificial photosynthesis, limits solar fuel efficiency. Despite progress in elucidating reaction mechanisms and theoretical predictions, the dynamic spatial coupling of charge transfer, localized structural motifs and active-site evolution remains unresolved, particularly as identified under operando conditions, obscuring key mechanistic pathways. Here, by integrating operando electrochemical shell-isolated nanoparticle-enhanced Raman spectroscopy with nanoscale electrochemical reaction imaging, we spatially resolve the atomic-scale interplay between hole transfer dynamics and the evolution of water oxidation intermediates that dictates the reaction kinetics on faceted BiVO4 particles. We show that dynamic structural adaption, mediated by multihole accumulation, governs the bifurcation of water oxidation pathways. At low surface hole densities (<0.67 nm−2), both (110) and (010) facets operate under single-hole transfer limitations, stabilizing hydroperoxo and peroxo intermediates, with the (110) facet evolving higher activity. On reaching a critical hole density threshold, the (010) facet evolves to be catalytically superior, exhibiting third-order power-law kinetics driven by the dynamic hole accumulation within Bi–O–V core structures via peroxo intermediates, whereas the (110) facet shifts to accumulate dual oxidizing equivalents, facilitating favourable intramolecular O–O coupling with higher energy demands. This work reveals water oxidation catalysis from static site-centric models to dynamic systems that are governed by hole-mediated structural adaptability, providing design principles for tailoring photocharge–catalyst architectures with atomic-scale precision for solar fuel generation.

0500化学一般
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