The challenge of achieving efficient photocatalytic H₂ production from water splitting without sacrificial agents remains a significant hurdle. Herein, we demonstrate that the dual doping of Cu/Co single atoms on Li-reduced blue TiO₂ (Cu–Co SA/BTO) can effectively modulate the charge separation of photogenerated carriers during photocatalytic pure water splitting. Remarkably, the H₂ evolution rate of Cu–Co SA/BTO achieves a remarkable value of 1238.15 μmol·g^–1·h^–1, surpassing that of BTO by 11 times. Particularly, femtosecond transient absorption spectroscopy (fs-TA) and differential charge densities reveal that the efficient electron–hole separation originates from the doping of Cu/Co dual-single atoms. The doping of Cu single atoms boosts electron transfer from the TiO₂ conduction band to Cu atoms, while the doping of Co single atoms facilitates photogenerated hole migration to Co single atoms from TiO₂. This work establishes a promising photocatalyst design strategy for achieving highly efficient H₂ evolution through pure water splitting, marking a significant step toward sustainable and green energy production.

中文翻译：

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双单原子光催化剂中的有效电荷分离，用于无牺牲剂析氢

在不使用牺牲剂的情况下通过水分解实现高效光催化H ₂生产的挑战仍然是一个重大障碍。在此，我们证明了Cu/Co单原子在Li还原的蓝色TiO ₂ (Cu-Co SA/BTO)上的双重掺杂可以有效地调节光催化纯水分解过程中光生载流子的电荷分离。值得注意的是，Cu-Co SA/BTO的H _{2析出速率达到了1238.15 μmol·g} ^–1 ·h ^–1的惊人值，是BTO的11倍。特别是，飞秒瞬态吸收光谱（fs-TA）和差分电荷密度表明，有效的电子空穴分离源于Cu/Co双单原子的掺杂。 Cu单原子的掺杂促进电子从TiO ₂导带到Cu原子的转移，而Co单原子的掺杂促进光生空穴从TiO ₂迁移到Co单原子。这项工作建立了一种有前景的光催化剂设计策略，通过纯水分解实现高效H _{2析出，标志着朝着可持续和绿色能源生产迈出的重要一步。}