Hematite (α-Fe₂O₃) material is regarded as a promising candidate for solar-driven water splitting because of the low cost, chemical stability, and appropriate bandgap; however, the corresponding system performances are limited by the poor electrical conductivity, short diffusion length of minority carrier, and sluggish oxygen evolution reaction. Here, we introduce the in situ Sn doping into the nanoworm-like α-Fe₂O₃ film with ultrasonic spray pyrolysis method. We show that the current density at 1.23 V vs. RHE (J_ph@1.23V) under one-sun illumination can be improved from 10 to 130 μA/cm² after optimizing the Sn dopant density. Moreover, J_ph@1.23V can be further enhanced 25-folds compared to the untreated counterpart via the post-rapid thermal process (RTP), which is used to introduce the defect doping of oxygen vacancy. Photoelectrochemical impedance spectrum and Mott-Schottky analysis indicate that the performance improvement can be ascribed to the increased carrier density and the decreased resistances for the charge trapping on the surface states and the surface charge transferring into the electrolyte. X-ray photoelectron spectrum and X-ray diffraction confirm the existence of Sn and oxygen vacancy, and the potential influences of varying levels of Sn doping and oxygen vacancy are discussed. Our work points out one universal approach to efficiently improve the photoelectrochemical performances of the metal oxide semiconductors.

赤铁矿（α-Fe ₂ O ₃）材料具有成本低、化学稳定性好、带隙合适等优点，被认为是太阳能驱动水分解的有希望的候选材料；然而，相应的系统性能受到导电性差、少数载流子扩散长度短和析氧反应缓慢的限制。在这里，我们采用超声喷雾热解法将Sn原位掺杂引入纳米蠕虫状α-Fe ₂ O ₃薄膜中。我们表明，在优化 Sn 掺杂剂密度后，单日光照下 1.23 V 与 RHE ( J _ph@1.23V ) 的电流密度可以从 10 提高到 130 μA/cm ^{2 。}此外，J _ph@1.23V通过用于引入氧空位缺陷掺杂的后快速热处理（RTP），与未处理的对应物相比，可以进一步增强 25 倍。光电化学阻抗谱和 Mott-Schottky 分析表明，性能的提高可归因于载流子密度的增加和表面态电荷俘获和表面电荷转移到电解质中的电阻降低。X射线光电子能谱和X射线衍射证实了Sn和氧空位的存在，并讨论了不同程度的Sn掺杂和氧空位的潜在影响。我们的工作指出了一种有效提高金属氧化物半导体光电化学性能的通用方法。