We report an anomalous photoinduced reconstructing and dark self-healing process on Bi₂O₂S nanoplates by monitoring the time profile of open-circuit potential (OCP). When the light was switched on and off on the nanoplates, we observed pronounced and repeatable decrement–recovery cycles of the OCP signal, which are inexplicable by a rapid electron–hole separation–recombination process only as in a conventional semiconductor. It is proposed that upon irradiation, accumulation of photogenerated holes at the electrode surface caused oxidation of the S layers of Bi₂O₂S nanoplates into certain intermediates, which, when the light was turned off, were then reduced back to the original state by the electron back flow. Raman scattering spectroscopy provided te S–S vibrational signature of the intermediate, evidencing the hole oxidative dimerization of the S^2– species and the inverse reductive S–S dissociation process. The photophysics and photochemistry of semiconductor nanoplates reported here may inspire the development of energy devices, switches, and memristors.

中文翻译：

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Bi2O2S纳米板上的异常光诱导重建和黑暗自我修复过程。

我们通过监测开路电势（OCP）的时间曲线报告了Bi ₂ O ₂ S纳米板上的异常光诱导重建和黑暗自我修复过程。当在纳米板上打开和关闭光时，我们观察到了OCP信号明显且可重复的减量-恢复周期，而快速的电子-空穴分离-重组过程是无法解释的，仅在常规半导体中是无法解释的。提出在辐照时，光生空穴在电极表面的积累引起Bi ₂ O ₂的S层的氧化。S纳米板变成某些中间体，当光被关闭时，这些中间体随后通过电子回流而还原回到原始状态。拉曼散射光谱提供了中间体的S–S振动特征，证明了S ^2–物种的空穴氧化二聚作用和逆还原S–S解离过程。本文报道的半导体纳米板的光物理和光化学可能会激发能源设备，开关和忆阻器的发展。