太陽光を利用した水の光触媒分解による水素製造の革新（China Achieves Breakthrough in Solar-powered Water Splitting for Hydrogen Production）

2025-04-09 中国科学院(CAS)

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• https://english.cas.cn/newsroom/cas_media/202504/t20250409_1040845.shtml
• https://pubs.acs.org/doi/10.1021/jacs.5c01936

見かけの量子収率30％を達成した光触媒的総合水分解のためのScドープ酸化ルチルTiO2における自発的励起子解離 Spontaneous Exciton Dissociation in Sc-Doped Rutile TiO2 for Photocatalytic Overall Water Splitting with an Apparent Quantum Yield of 30%

Fei Qin,Yuyang Kang,Xingyuan San,Yun-Long Tang,Jianjun Li,Xin Zhang,Kangyu Zhang,and Gang Liu
Journal of the American Chemical Society  Published: April 7, 2025
DOI:https://doi.org/10.1021/jacs.5c01936

Abstract

Achieving high-efficiency photocatalytic overall water splitting with earth-abundant materials like TiO₂ under ambient conditions is a compelling renewable energy solution. However, this remains challenging due to both the presence of rich deep-level defects and lack of strong driving force in particulate photocatalysts, limiting the separation of photogenerated charges. Here, we developed a scandium (Sc)-doped rutile TiO₂ with fully passivated detrimental Ti³⁺ defects and very strong built-in electric field arising from engineered (101)/(110) facet junctions. The Sc³⁺ doping enables a much lower exciton binding energy of 8.2 meV (28.6 meV for undoping) than room-temperature thermal fluctuation energy, indicating spontaneous exciton dissociation. These features enable the photogenerated electrons and holes to selectively transfer to the (110) and (101) facets, respectively. The resulting Sc-doped TiO₂ with cocatalyst delivers photocatalytic overall water splitting with an apparent quantum yield of 30.3% at 360 nm and a solar-to-hydrogen conversion efficiency of 0.34%, representing the highest values reported for TiO₂-based photocatalysts under ambient conditions.