Source: material analysis and Application
Introduction to achievements:
Energy shortage and environmental pollution are the main problems facing the current global economic development. It is of great significance to develop green and sustainable energy technologies to alleviate the current social energy shortage and prevent and control environmental pollution. Microbial fuel cell (MFC), as a new capacity equipment, has the functions of sewage purification and ecological environment restoration because of its green environmental protection, low operating cost and good stability. Based on this, the research group of Professor wangyuqiao of Southeast University and the research group of Professor xiekun of Chongqing Three Gorges University published a report entitled“ MXene@MnO2 /Carbon cloth as an anode for microbial fuel cells ".
In this work, mxene with high conductivity and good hydrophilicity was used as the substrate, and MnO2 nano sheets with strong biocompatibility were orderly grown on its surface, and constructed on the surface of carbon cloth MXene@MnO2 Electrodes. Because of its high pore structure, good biocompatibility and super hydrophilicity, it enhances its extracellular electron transfer as MFC anode (Fig. 1), thus promoting the rapid start-up and power output of MFC. The preparation process of this kind of anode is simple and the reaction conditions are warm, which is suitable for large-scale industrialization.
Figure 1 MXene@MnO2 Enhanced extracellular electron transport
Key points of the article
Key point 1: promote the quick start of battery
In order to realize the rapid start-up, efficient and stable operation of MFC, and then improve its power generation performance and waste reduction efficiency, researchers are working hard to develop high-performance anodes.
Compared with nitrogen doped graphitized carbon, conductive polymer and other materials, MnO2 nano sheets are orderly grown on the surface of mxene substrate and then modified with carbon cloth as anode in this work, which has the advantages of simple preparation process, green environmental protection and low cost. The constructed anode has the characteristics of high conductivity, good hydrophilicity and high biocompatibility, MXene@MnO2 The modified carbon cloth as an anode helps the microbial community to rapidly colonize and reproduce on its surface, so as to realize the rapid start-up of MFC, and its start-up time is as short as 70H.
Key point 2:enhance output energy density
The low output power density of traditional MFC seriously restricts its industrial popularization and application. Literature research shows that the output of its power density is closely related to the internal resistance of the biological anode and the process of extracellular electron transfer. The smaller the internal resistance of the anode, the faster the extracellular electron transfer, the more conducive to the output of energy and improve its energy density.
In view of this, the MXene@MnO2 The load of electroactive bacteria on its surface is significantly increased, and the electrons produced by its metabolism can be quickly transferred to the external circuit through the composite structure. MXene@MnO2 The special structure of MFC improves the electrical performance of the anode and promotes the process of extracellular electron transfer, thus enhancing the output power density of MFC, which is increased to 746.3 MW · m-2.
Key point 3: efficient degradation of organic pollutants
The traditional MFC anode chamber has a single colony structure and slow metabolism of refractory organic pollutants, resulting in low waste reduction performance and energy recovery efficiency, which seriously restricts its application in environmental treatment and energy recovery.
MXene@MnO2 The modified carbon cloth anode surface can form a dense and thick biofilm with rich microbial community structure and strong metabolic capacity. Therefore, it has the characteristics of strong degradation of organic pollutants, high degradation efficiency of Congo red dye and good cyclic degradation performance. Therefore, MXene@MnO2 The modified carbon cloth anode assembled MFC shows potential application in the field of environmental treatment and energy recovery.
Graphic Guide
Figure 2（a）MXene，（b）MnO2和（c-d）MnO2
Figure 3 (a, b) XRD pattern; (c) MnO2@MXene /Wetting angle of CC, (d) mno2/cc, (E) CC and (f) mxene/cc anode materials
Figure 4 (a) MnO2@MXene /SEM images of the biofilm on the anode surfaces of CC, (b) mno2/cc, (c) mxene/cc and (d) CC
Figure 5 electrochemical properties of anode before inoculation (a, c) and after inoculation (B, d)
Figure 6 (a) degradation efficiency of Congo red dye in MFC and (b) MnO2@MXene /Cyclic degradation performance of cc-mfc
Literature:
https://doi.org/10.1002/slct.202200612
