The application of microbe-photocatalyst biohybrid (MPB) systems to pollutant removals has drawn considerable attentions due to the high demands on energy shortage and environmental pollution prevention. However, the stability and utilization rate of photoelectrons generated under the photocatalysis of plasmonic metals are still low. Herein, we constructed a new Au-TiO₂/Shewanella biohybrid system by combining photocatalyst and electrogenic bacteria to realize the plasmon-induced visible-light-driven reduction of hexavalent chromium. The highly hydrophilic Au-TiO₂ and the outer membrane protein (OmcA) of Shewanella were effectively complexed to form a tight composite. The irradiation of visible light increases the expression level of extracellular polymeric substances (EPS) in the MPB system and upregulates the function gene of OmcA and MtrC, suggesting that the photoelectrons are absorbed by the conductive protein and deposited into the microbes to realize high efficiency chromium removal (68.9%). This study successfully utilize the photogenerated electrons under the catalysis of plasmonic gold nanoparticles and opens up a new avenue to the application of MPB system in water treatment.

中文翻译：

---

使用 Au-TiO2/Shewanella 生物杂交实现高效等离激元诱导的可见光驱动还原六价铬


由于对能源短缺和环境污染防治的高要求，微生物-光催化剂生物杂化 （MPB） 系统在污染物去除中的应用引起了相当大的关注。然而，在等离子体金属的光催化下产生的光电子的稳定性和利用率仍然很低。在此，我们通过结合光催化剂和生电细菌构建了一种新的 Au-TiO₂/Shewanella 生物杂交系统，实现了等离激元诱导的可见光驱动还原六价铬。高度亲水性的 Au-TiO₂ 和 Shewanella 的外膜蛋白 （OmcA） 有效地复合形成紧密复合材料。可见光照射增加了 MPB 系统中细胞外聚合物物质 （EPS） 的表达水平，并上调了 OmcA 和 MtrC 的功能基因，表明光电子被导电蛋白吸收并沉积到微生物中，实现高效除铬 （68.9%）。本研究在等离子体金纳米颗粒的催化下成功利用了光生电子，为 MPB 系统在水处理中的应用开辟了一条新途径。