Regulating the Electronic Structure of Cu-N x Active Sites for Efficient and Durable Oxygen Reduction Catalysis to Improve Microbial Fuel Cell Performance.
Qiu-Ren PanBi-Lin LaiLi-Juan HuangYan-Nan FengNan LiZhao-Qing LiuPublished in: ACS applied materials & interfaces (2022)
The efficient and durable oxygen reduction reaction (ORR) catalyst is of great significance to boost power generation and pollutant degradation in microbial fuel cells (MFCs). Although transition metal-nitrogen-codoped carbon materials are an important class of ORR catalysts, copper-nitrogen-codoped carbon is not considered a suitable MFC cathode catalyst due to the insufficient performance and especially instability. Herein, we report a three-dimensional (3D) hierarchical porous copper, nitrogen, and boron codoped carbon (3DHP Cu-N/B-C) catalyst synthesized by the dual template method. The introduced B atom as an electron donor increases the electron density around the Cu-N x active site, which significantly promotes the efficiency of the ORR process and stabilizes the active site by preventing demetallization. Thus, the 3DHP Cu-N/B-C catalyst exhibited excellent ORR performance with the half-wave potential of 0.83 V (vs reversible hydrogen electrode (RHE)) in a 0.1 M KOH electrolyte and 0.68 V (vs RHE) in a 50 mM PBS electrolyte. Meanwhile, 3DHP Cu-N/B-C had satisfactory stability with 94.16% current retention after 24 h of chronoamperometry test, which is better than that of 20% Pt/C. The MFCs using 3DHP Cu-N/B-C not only showed a maximum power density of up to 760.14 ± 19.03 mW m -2 but also operating durability of more than 50 days. Moreover, the 16S rDNA sequencing results presented that the 3DHP Cu-N/B-C catalyst had a positive effect on the microbial community of the MFC with more anaerobic electroactive bacteria in the anode biofilm and fewer aerobic bacteria in the cathode biofilm. This study provides a new approach for the development of Cu-based ORR electrocatalysts as well as guidance for the rational design of high-performance MFCs.
Keyphrases
- metal organic framework
- microbial community
- reduced graphene oxide
- ionic liquid
- highly efficient
- room temperature
- aqueous solution
- visible light
- ion batteries
- staphylococcus aureus
- pseudomonas aeruginosa
- carbon dioxide
- induced apoptosis
- single cell
- gold nanoparticles
- mesenchymal stem cells
- cell therapy
- escherichia coli
- bone marrow
- biofilm formation
- heavy metals
- high intensity