Institute for Clean Energy and Advanced Materials, Faculty of Materials and Energy , Southwest University , Chongqing 400715 , China.
Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies , Chongqing 400715 , P.R. China.
ACS Appl Mater Interfaces. 2018 Apr 11;10(14):11671-11677. doi: 10.1021/acsami.7b19826. Epub 2018 Mar 30.
Interfacial electron transfer between an electroactive biofilm and an electrode is a crucial step for microbial fuel cells (MFCs) and other bio-electrochemical systems. Here, a hierarchically porous nitrogen-doped carbon nanotubes (CNTs)/reduced graphene oxide (rGO) composite with polyaniline as the nitrogen source has been developed for the MFC anode. This composite possesses a nitrogen atom-doped surface for improved flavin redox reaction and a three-dimensional hierarchically porous structure for rich bacterial biofilm growth. The maximum power density achieved with the N-CNTs/rGO anode in S. putrefaciens CN32 MFCs is 1137 mW m, which is 8.9 times compared with that of the carbon cloth anode and also higher than those of N-CNTs (731.17 mW m), N-rGO (442.26 mW m), and the CNTs/rGO (779.9 mW m) composite without nitrogen doping. The greatly improved bio-electrocatalysis could be attributed to the enhanced adsorption of flavins on the N-doped surface and the high density of biofilm adhesion for fast interfacial electron transfer. This work reveals a synergistic effect from pore structure tailoring and surface chemistry designing to boost both the bio- and electrocatalysis in MFCs, which also provide insights for the bioelectrode design in other bio-electrochemical systems.
在微生物燃料电池(MFC)和其他生物电化学系统中,活性生物膜与电极之间的界面电子转移是至关重要的一步。在这里,我们开发了一种具有聚苯胺作为氮源的分层多孔氮掺杂碳纳米管(CNTs)/还原氧化石墨烯(rGO)复合材料,作为 MFC 的阳极。该复合材料具有氮原子掺杂表面,可改善黄素氧化还原反应,具有三维分层多孔结构,有利于细菌生物膜的生长。在 S. putrefaciens CN32 MFC 中,N-CNTs/rGO 阳极的最大功率密度达到 1137 mW m-2,是碳布阳极的 8.9 倍,也高于 N-CNTs(731.17 mW m-2)、N-rGO(442.26 mW m-2)和未掺杂氮的 CNTs/rGO(779.9 mW m-2)复合材料。生物电化学催化性能的大幅提高可归因于氮掺杂表面上黄素的增强吸附和有利于快速界面电子转移的高密度生物膜附着。这项工作揭示了孔结构剪裁和表面化学设计的协同效应,可同时提高 MFC 中的生物和电化学催化性能,这也为其他生物电化学系统中的生物电极设计提供了新的思路。