The construction of interfacial electric field (IEF) in semiconductor heterojunction is of great significance in boosting photocatalytic hydrogen evolution through efficient separation of photogenerated charge-carriers. However, the exploitation of IEF in type-I heterojunction has not been proposed for designing photocatalysts. Herein, based on the density functional theory prediction, p-SnS with different work functions modulated by Sn-vacancy are compounded with n-ZnIn₂S₄ containing S-vacancy to form type-I heterojunction. The optimized SnS/ZnIn₂S₄ photocatalyst without co-catalysts exhibits an impressive hydrogen evolution rate of 22.75 mmol g⁻¹ h⁻¹, 6.23 times of ZnIn₂S₄. Systematic investigations reveal that the interfacial Sn-S bond acts as a transport channel that accelerates the interface charge-carriers transfer under the promotion of IEF originating from the significant Fermi level difference. A large difference in the surface photovoltage signal of SnS/ZnIn₂S₄ and ZnIn₂S₄ is achieved from effective photogenerated charge-carriers separation by IEF. The new p-n type-I scheme of SnS/ZnIn₂S₄ induced by the interfacial mediation can separate the photogenerated charge-carriers, and retain the highly reductive electrons of ZnIn₂S₄ for hydrogen evolution, overcoming the disadvantage of reduction potential decline in the typical type-I scheme. This study will afford a new theoretical basis for the achievement of high-efficiency photocatalytic hydrogen evolution through interface modulation.

中文翻译：

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p-SnS/n-ZnIn2S4 的 Sn 和 S 空位的界面介导通过 I 型异质结的新方案增强光催化析氢

半导体异质结中界面电场（IEF）的构建对于通过光生载流子的有效分离促进光催化析氢具有重要意义。然而，尚未提出在 I 型异质结中利用 IEF 来设计光催化剂。在此，基于密度泛函理论预测，受Sn空位调制的不同功函数的p -SnS与含有S空位的n - ZnIn ₂ S ₄复合形成I型异质结。没有助催化剂的优化SnS/ZnIn ₂ S _{4光催化剂表现出令人印象深刻的22.75 mmol g} ^-1 h ^{-1的析氢速率，是ZnIn} ₂ S ₄的6.23倍。系统研究表明，界面 Sn-S 键作为传输通道，在显着费米能级差异的 IEF 促进下加速界面载流子传输。_{SnS/ZnIn 2} S ₄和ZnIn ₂ S ₄表面光电压信号的巨大差异是通过IEF有效的光生载流子分离实现的。_{界面介导诱导的SnS/ZnIn 2} S ₄新型pn I型方案可以分离光生载流子，并保留ZnIn ₂ S ₄的高还原性电子用于析氢，克服了还原电位下降的缺点。典型的I型方案。该研究将为通过界面调制实现高效光催化析氢提供新的理论基础。