Xu Feiyan, Mei Wantian, Hu Peiyu, Zheng Luoxuan, Zhang Jianjun, Cao Heng, García Hermenegildo, Yu Jiaguo
Laboratory of Solar Fuel, Faculty of Materials Science and Chemistry, China University of Geosciences, 68 Jincheng Street, Wuhan, 430078, P.R. China.
Instituto Universitario de Tecnología Química, CSIC-UPV, Universitat Politècnica de València, Valencia, 46022, Spain.
Angew Chem Int Ed Engl. 2025 Sep 22;64(39):e202513364. doi: 10.1002/anie.202513364. Epub 2025 Aug 11.
Photocatalytic CO reduction into solar fuels presents a promising strategy for carbon mitigation and sustainable energy conversion. However, single-component photocatalysts suffer from inefficient charge separation, while binary heterojunctions-even with cocatalysts assistance-often undergo rapid Coulombic recombination due to timescale mismatches between ultrafast charge transfer and slower surface reaction kinetics. To overcome these limitations, a spatially engineered NbC/NbO/ZnO ternary heterostructure is developed by anchoring ZnO quantum dots (QDs) onto NbO nanorods grown in situ from NbC MXene. This architecture integrates an NbO/ZnO S-scheme heterojunction and an NbC/NbO Schottky junction, sharing NbO as a central mediator, thereby establishing bidirectional interfacial electric fields (IEFs) that direct photogenerated electrons toward ZnO and holes toward NbC. In situ irradiated X-ray photoelectron spectroscopy (XPS), X-ray absorption fine structure (XAFS), and femtosecond transient absorption spectroscopy (fs-TAS) reveal interface-specific electronic interactions and time-resolved carrier dynamics, confirming efficient and spatially resolved charge migration across the decoupled interfaces. This spatial charge separation effectively suppresses Coulombic recombination and prolongs carrier lifetimes. Additionally, the photothermal effect of NbC MXene enhances CO chemisorption and activation at defective ZnO QDs. These synergistic effects collectively enable high-efficiency CO photoreduction without molecular cocatalysts or sacrificial agents, providing a mechanistically distinct and scalable approach for artificial photosynthesis.
光催化将二氧化碳还原为太阳能燃料是一种有前景的碳减排和可持续能源转换策略。然而，单组分光催化剂存在电荷分离效率低的问题，而二元异质结——即使有共催化剂的协助——由于超快电荷转移和较慢的表面反应动力学之间的时间尺度不匹配，往往会经历快速的库仑复合。为了克服这些限制，通过将氧化锌量子点（QDs）锚定在由碳化铌MXene原位生长的氧化铌纳米棒上，开发了一种空间工程化的碳化铌/氧化铌/氧化锌三元异质结构。这种结构整合了氧化铌/氧化锌S型异质结和碳化铌/氧化铌肖特基结，以氧化铌作为中心介质，从而建立双向界面电场（IEF），将光生电子导向氧化锌，空穴导向碳化铌。原位辐照X射线光电子能谱（XPS）、X射线吸收精细结构（XAFS）和飞秒瞬态吸收光谱（fs-TAS）揭示了界面特异性电子相互作用和时间分辨的载流子动力学，证实了跨解耦界面的高效和空间分辨电荷迁移。这种空间电荷分离有效地抑制了库仑复合，延长了载流子寿命。此外，碳化铌MXene的光热效应增强了在有缺陷的氧化锌量子点处的一氧化碳化学吸附和活化。这些协同效应共同实现了无分子共催化剂或牺牲剂的高效一氧化碳光还原，为人工光合作用提供了一种机制上不同且可扩展的方法。
