MoN nanobelt cathodes for efficient hydrogen production in microbial electrolysis cells with shaped biofilm microbiome
High cost platinum (Pt) catalysts limit the application of microbial electrolysis cells (MECs) for hydrogen (H) production. Here, inexpensive and efficient MoN nanobelt cathodes were prepared using an ethanol method with minimized catalyst and binder loadings. The chronopotentiometry tests demonstrated that the MoN nanobelt cathodes had similar catalytic activities for H evolution compared to that of Pt/C (10 wt%). The H production rates (0.39 vs. 0.37 m-H/m/d), coulombic efficiencies (90% vs. 77%), and overall hydrogen recovery (74% vs. 70%) of MECs with the MoN nanobelt cathodes were also comparable to those with Pt/C cathodes. However, the cost of MoN nanobelt catalyst ($ 31/m) was much less than that of Pt/C catalysts ($ 1930/m). Furthermore, the biofilm microbiomes at electrodes were studied using the PacBio sequencing of full-length 16S rRNA gene. It indicated Stenotrophomonas nitritireducens as a putative electroactive bacterium dominating the anode biofilm microbiomes. The majority of dominant species in the MoN and Pt/C cathode communities belonged to Stenotrophomonas nitritireducens, Stenotrophomonas maltophilia, and Comamonas testosterone. The dominant populations in the cathode biofilms were shaped by the cathode materials. This study demonstrated MoN nanobelt catalyst as an alternative to Pt catalyst for H production in MECs.
Publication Source (Journal or Book title)
Biosensors & bioelectronics
Lu, S., Lu, B., Tan, G., Moe, W., Xu, W., Wang, Y., Xing, D., & Zhu, X. (2020). MoN nanobelt cathodes for efficient hydrogen production in microbial electrolysis cells with shaped biofilm microbiome. Biosensors & bioelectronics, 167, 112491. https://doi.org/10.1016/j.bios.2020.112491