Abstract Multi-layered hematite (α-Fe2O3) films were prepared on fluorine-doped tin oxide (FTO) using the dip coating method. The first three layers of the films were annealed at 500 °C and fourth layers at 500, 600, 700, 750 and 800 °C respectively, and their photoelectrochemical (PEC) performance was investigated. Films annealed at 750 °C recorded the best performance, producing 0.19 mA/cm2 photocurrent at 1.23 V vs reversible hydrogen electrode (RHE); 5.3 times more than what was recorded for films sintered at 500 °C, and the onset potential yielded a cathodic shift of 300 mV. The enhanced performance was linked to improved crystallization, absorption coefficient, lowered flat band potential, increased charge carrier density, decreased charge transfer resistance at the solid/liquid interface and increased surface states capacitance for films annealed at 750 °C. The PEC performance of multi-layered α-Fe2O3 films could be improved by annealing the last layers at elevated temperatures without damaging the conducting substrates.

中文翻译：

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制备用于光电化学分解水的多层赤铁矿薄膜的改良退火方法

摘要 采用浸涂法在掺氟氧化锡（FTO）上制备了多层赤铁矿（α-Fe2O3）薄膜。薄膜的前三层分别在 500°C 和第四层在 500、600、700、750 和 800°C 下退火，并研究了它们的光电化学（PEC）性能。在 750 °C 下退火的薄膜记录了最佳性能，在 1.23 V 与可逆氢电极 (RHE) 下产生 0.19 mA/cm2 光电流；比在 500 °C 下烧结的薄膜所记录的值高 5.3 倍，并且起始电位产生了 300 mV 的阴极位移。增强的性能与改进的结晶、吸收系数、降低的平带电位、增加的电荷载流子密度、降低了固/液界面处的电荷转移电阻，并增加了在 750 °C 下退火的薄膜的表面状态电容。多层α-Fe2O3 薄膜的PEC 性能可以通过在不损坏导电基板的情况下在高温下对最后一层进行退火来提高。