Abstract Anaerobic photocatalysis of semiconductors is a promising approach for the remediation of refractory pollutants which are readily reduced rather than oxidized. To sustain the operation of photoreduction, hole scavengers must be supplied. Bacteria as hole scavengers have attracted great attention. Thus, a bio-photoelectric reductive degradation system (BPRDS) was established by integrating nano-Ag3PO4 and Shewanella oneidensis MR-1. Photodegradation performance of BPRDS was evaluated via degrading p-chlorophenol (p-CP). Results showed that p-CP could be degraded by BPRDS under anaerobic photoexcitation conditions, but not be decomposed by Shewanella cells or nano-Ag3PO4. Block of extracellular electron transfer of S. oneidensis MR-1 could reduce p-CP degradation in BPRDS, implying bio-electrons were involved in anaerobic photodegradation process. Dose of riboflavin decreased the photodegradation efficiency significantly. DFT calculations revealed that bio-electrons released by S. oneidensis MR-1 could be transferred to photogenerated holes of nano-Ag3PO4 to exert biological hole scavengers. Hole and hydroxyl radical scavengers could not prevent degradation of p-CP in BPRDS, implying p-CP was removed via photoreduction rather than photooxidation. Our results demonstrate that EAB can act as biological hole scavengers for anaerobic photodegradation of pollutants, which will contribute to the application of BPRDS for environmental remediation.

中文翻译：

---

通过密度泛函理论计算阐明生物光电还原降解系统中对氯苯酚的光降解

摘要 半导体的厌氧光催化是修复难降解污染物的一种有前景的方法，这些污染物易于还原而不是氧化。为了维持光还原作用，必须提供空穴清除剂。细菌作为空穴清除剂引起了人们的极大关注。因此，通过整合纳米Ag3PO4和Shewanella oneidensis MR-1建立了生物光电还原降解系统（BPRDS）。通过降解对氯苯酚 (p-CP) 来评估 BPRDS 的光降解性能。结果表明，p-CP在厌氧光激发条件下可被BPRDS降解，而不能被希瓦氏菌或纳米Ag3PO4分解。阻断 S. oneidensis MR-1 的细胞外电子转移可以减少 BPRDS 中 p-CP 的降解，暗示生物电子参与了厌氧光降解过程。核黄素剂量显着降低光降解效率。DFT 计算表明，S. oneidensis MR-1 释放的生物电子可以转移到纳米 Ag3PO4 的光生孔中，发挥生物空穴清除剂的作用。空穴和羟基自由基清除剂不能阻止 BPRDS 中 p-CP 的降解，这意味着 p-CP 是通过光还原而不是光氧化去除的。我们的研究结果表明，EAB 可以作为厌氧光降解污染物的生物空穴清除剂，这将有助于 BPRDS 在环境修复中的应用。oneidensis MR-1 可以转移到纳米 Ag3PO4 的光生空穴中以发挥生物空穴清除剂的作用。空穴和羟基自由基清除剂不能阻止 BPRDS 中 p-CP 的降解，这意味着 p-CP 是通过光还原而不是光氧化去除的。我们的研究结果表明，EAB 可以作为厌氧光降解污染物的生物空穴清除剂，这将有助于 BPRDS 在环境修复中的应用。oneidensis MR-1 可以转移到纳米 Ag3PO4 的光生空穴中以发挥生物空穴清除剂的作用。空穴和羟基自由基清除剂不能阻止 BPRDS 中 p-CP 的降解，这意味着 p-CP 是通过光还原而不是光氧化去除的。我们的研究结果表明，EAB 可以作为厌氧光降解污染物的生物空穴清除剂，这将有助于 BPRDS 在环境修复中的应用。