School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China.
School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China; Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, Suzhou University of Science and Technology, Suzhou, Jiangsu 215009, China.
Bioelectrochemistry. 2024 Aug;158:108723. doi: 10.1016/j.bioelechem.2024.108723. Epub 2024 May 3.
Bidirectional electron transfer is about that exoelectrogens produce bioelectricity via extracellular electron transfer at anode and drive cytoplasmic biochemical reactions via extracellular electron uptake at cathode. The key factor to determine above bioelectrochemical performances is the electron transfer efficiency under biocompatible abiotic/biotic interface. Here, a graphene/polyaniline (GO/PANI) nanocomposite electrode specially interfacing exoelectrogens (Shewanella loihica) and augmenting bidirectional electron transfer was conducted by in-situ electrochemical modification on carbon paper (CP). Impressively, the GO/PANI@CP electrode tremendously improved the performance of exoelectrogens at anode for wastewater treatment and bioelectricity generation (about 54 folds increase of power density compared to blank CP electrode). The bacteria on electrode surface not only showed fast electron release but also exhibited high electricity density of extracellular electron uptake through the proposed direct electron transfer pathway. Thus, the cathode applications of microbial electrosynthesis and bio-denitrification were developed via GO/PANI@CP electrode, which assisted the close contact between microbial outer-membrane cytochromes and nanocomposite electrode for efficient nitrate removal (0.333 mM/h). Overall, nanocomposite modified electrode with biocompatible interfaces has great potential to enhance bioelectrochemical reactions with exoelectrogens.
双向电子传递是指外电子体通过阳极的细胞外电子传递产生生物电能，并通过阴极的细胞外电子摄取来驱动细胞质生化反应。决定上述生物电化学性能的关键因素是生物相容的非生物/生物界面下的电子传递效率。在这里，通过在碳纸上进行原位电化学修饰，制备了一种专门用于外电子体（希瓦氏菌）并增强双向电子传递的石墨烯/聚苯胺（GO/PANI）纳米复合材料电极。令人印象深刻的是，GO/PANI@CP 电极极大地提高了阳极处理废水和产生生物电能的外电子体性能（与空白 CP 电极相比，功率密度提高了约 54 倍）。电极表面的细菌不仅表现出快速的电子释放，而且通过所提出的直接电子转移途径表现出高的细胞外电子摄取的电密度。因此，通过 GO/PANI@CP 电极开发了微生物电化学合成和生物反硝化的阴极应用，这有助于微生物外膜细胞色素与纳米复合材料电极的紧密接触，从而有效地去除硝酸盐（0.333 mM/h）。总的来说，具有生物相容性界面的纳米复合材料修饰电极具有增强与外电子体的生物电化学反应的巨大潜力。
