Novel fluorinated MIL-88B assisted hydrogen-bonded organic framework derived high efficiency oxygen reduction catalyst in microbial fuel cell

The crux to promote the utilization of air-cathode microbial fuel cell (AC-MFC) is to find high-efficiency and low- budget oxygen reduction reaction (ORR) catalysts, which can replace Pt-based catalysts, reduce electrode cost and thus improve the cost-effectiveness of AC-MFC. In this work, a three-dimensional network carbon structure F-MIL-HOF loaded with Fe2O3 2 O 3 material composites have been successfully synthesized by carbonizing by NH4F- 4 F- fluorinated MIL-88B combined with a high nitrogen content hydrogen-bonded organic framework (HOF) to evince excellent catalytic property for ORR in both alkaline and neutral electrolytes. The Fe2O3 2 O 3 obtained after carbonization of MIL-88B portrays efficient ORR catalytic activity, and the combination with the natural pore- rich HOF precisely solves the problems of uncontrolled growth and agglomeration during Fe2O3 2 O 3 synthesis, achieving the high dispersion and full exposure of Fe2O3 2 O 3 nanoparticles as active sites. As-synthesized F-MIL-HOF as cathodic catalyst reaches a limiting current density of 6.40 mA cm- 2 in alkaline condition, which exhibits an advantage performance over commercial Pt/C (6.26 mA cm-- 2 ). Furthermore, F-MIL-HOF shows approximately four-electron pathway with better methanol resistance and stability than Pt/C, and the performance only decreases by 10.2 % in the stability test, which still had efficient ORR catalytic performance. F-MIL-HOF is an emerging alternative electro-catalyst for AC-MFC.