The interfacial charge dynamics was crucial for semiconductor heterostructure photocatalysis. Through the rational design of the heterostructure interface, heterojunction expressed variable recombination and migration dynamics for excited carriers. Herein, followed by a typical chemical bath strategy with the hexagonal cadmium sulfide (CdS) overlapped on the exfoliated molybdenum disulfide (MoS₂) film, we developed a cadmium sulfide/molybdenum disulfide (CdS-MoS₂) nano-heterojunction and investigated the interfacial charge dynamics for photocatalytic hydrogen evolution. Photoelectron spectroscopy detected an energetic offset between CdS and MoS₂, revealing the formation of an interfacial electric field with efficient charges separation. Through transient absorption spectra, we demonstrated the type-II contact at the CdS-MoS₂ interface. Driven by the electric field, the excited carriers separated and rapidly migrated to sub-band defects of CdS within the first 500 fs. The carriers-restricted defects provided catalytic active sites, endowing CdS-MoS₂ a highly efficient photocatalytic capability. Consequentially, the CdS-MoS₂ achieved an enhanced hydrogen evolution rate of 2.3 mmol·g⁻¹·h⁻¹ with significantly stronger photocurrent density. This work gave an insight to the channel of interfacial separation and migration for excited carriers, which could contribute to the interfacial engineering of advanced heterojunction photocatalysts.

界面电荷动力学对于半导体异质结构光催化至关重要。通过异质结构界面的合理设计，异质结表达了激发载流子的可变复合和迁移动力学。在此，我们采用典型的化学浴策略，将六方硫化镉 (CdS) 重叠在剥离的二硫化钼 (MoS ₂ ) 薄膜上，开发了硫化镉/二硫化钼 (CdS-MoS ₂ ) 纳米异质结并研究了界面光催化析氢的电荷动力学。光电子能谱检测到 CdS 和 MoS _{2之间的能量偏移}，揭示了具有有效电荷分离的界面电场的形成。通过瞬态吸收光谱，我们证明了 CdS-MoS ₂界面处的 II 型接触。在电场的驱动下，激发的载流子在前 500 fs 内分离并迅速迁移到 CdS 的子带缺陷中。载流子限制的缺陷提供了催化活性位点，赋予了CdS-MoS ₂高效的光催化能力。因此，CdS-MoS ₂的析氢速率提高了 2.3 mmol·g ^-1 ·h ^-1具有明显更强的光电流密度。这项工作深入了解了受激载流子的界面分离和迁移通道，这可能有助于先进异质结光催化剂的界面工程。