Wide-bandgap semiconductors are generally effective for the photocatalytic degradation of VOCs under UV light irradiation. However, we found that various VOCs could be effectively degraded and even mineralized by a variety of wide-bandgap semiconductors under visible light irradiation. The findings of our study indicate that adsorption of VOCs on catalysts generated a narrow bandgap between the ground state of the adsorbed VOCs and the conduction band of the catalysts. Such a bandgap induced visible light absorption, generating photoelectrons that are subsequently transferred from the VOCs to the conduction band of the catalyst. The photoelectrons are then captured by the surrounding oxygen, producing reactive superoxide radicals to attack the VOCs, leading to their degradation and mineralization. The degradation efficiency of VOCs by semiconductors under visible light is greatly dependent on the types of semiconductors and VOCs. This study uncovers a new mechanism for wide-bandgap semiconductor photocatalytic degradation of VOCs in visible light irradiation.

中文翻译：

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可见光光催化的新机制：通过宽带隙半导体吸附有机化合物产生带内

宽带隙半导体通常对紫外光照射下的 VOC 光催化降解有效。然而，我们发现各种VOCs在可见光照射下可以被多种宽带隙半导体有效降解甚至矿化。我们的研究结果表明，VOC 在催化剂上的吸附在吸附的 VOC 的基态和催化剂的导带之间产生了狭窄的带隙。这种带隙诱导可见光吸收，产生光电子，随后从 VOC 转移到催化剂的导带。然后光电子被周围的氧气捕获，产生反应性超氧自由基来攻击挥发性有机化合物，导致其降解和矿化。可见光下半导体对VOCs的降解效率很大程度上取决于半导体和VOCs的类型。这项研究揭示了可见光照射下宽带隙半导体光催化降解VOCs的新机制。