Improving oxygen reduction reaction of microbial fuel cell by titanium dioxide attaching to dual metal organic frameworks as cathode

In this study, a two-step simple distributed feeding method was used to prepare the core-shell nanocomposite dual metal organic frameworks (D-MOFs, TiO2@ZIF-67/ZIF-8). There were three obvious peaks (011), (112), (222) interface in D-MOFs core, which fully showed that ZIF-67/ZIF-8 crystal core was successfully synthesized. The morphology of composite material was core-shell structure with a rough surface, and Ti, Co, Zn, Al were uniformly distributed on the surface. TiO2@ZIF-67/ZIF-8 also had excellent electrochemical activity and the maximum power density of TiO2@ZIF-67/ZIF-8 microbial fuel cell (MFC) was 341.506 mW/m(2), which was 1.30 times of ZIF-67/ZIF-8-MFC (262.144 mW/m(2)) and 2.07 times of ZIF-67-MFC (164.836 mW/m(2)). And the continuous output voltage of TiO2@ZIF-67/ZIF-8-MFC was 413.43 mV, which could maintain stable voltage output for 8.3 days. D-MOFs as the core of composites ensured the integrity, stability and high activity of materials; Rough TiO2 as the surface of the material provided surface area and reaction center.

Automated summary

A two-step simple distributed feeding method was used to prepare the core-shell nanocomposite dual metal organic frameworks TiO2@ZIF-67/ZIF-8. The composite material exhibited a core-shell structure with a rough surface, and showed excellent electrochemical activity with significantly higher power density and voltage output compared to other MOFs.