Bismuth oxide (Bi2O3), a yellow semiconductor ceramic, is considered as an advanced photoactive energy material, but its activity still needs further improvement for practical applications. In this study, black Bi2O3 with nanocrystalline structure and large fraction of oxygen vacancies is synthesized by mechanical straining via the high-pressure torsion (HPT) method. The black oxide exhibits enhanced light absorbance under both UV and visible lights. It shows a bipolar photocurrent behavior with up to six times higher photocurrent density compared with the unprocessed yellow Bi2O3. This study shows the high potential of severely-strained black Bi2O3 for photovoltaic, photoconductivity and photocatalytic applications.

中文翻译：

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通过高压扭转应变产生具有增强的光电流产生的新型黑色氧化铋 (Bi2O3)

氧化铋（Bi2O3）是一种黄色的半导体陶瓷，被认为是一种先进的光活性能源材料，但其活性仍需进一步提高以实现实际应用。在这项研究中，通过高压扭转 (HPT) 方法通过机械应变合成了具有纳米晶结构和大量氧空位的黑色 Bi2O3。黑色氧化物在紫外线和可见光下都表现出增强的吸光度。与未加工的黄色 Bi2O3 相比，它显示出双极光电流行为，光电流密度高达六倍。这项研究显示了严重应变的黑色 Bi2O3 在光伏、光电导和光催化应用方面的巨大潜力。