Robust Porous Fe,Co-Nc Cathode Catalyst Derived from SiO ₂ -Protected Ferrocene-ZIF-67 for Enhanced Microbial Fuel Cell Performance

The demand for efficient and sustainable energy sources has intensified research toward microbial fuel cells (MFCs) as a potential solution. One of the key challenges in MFC technology is the development of cost-effective and high-performance cathode catalysts, as traditional noble metal catalysts are expensive and limited in supply. In this work, a SiO 2 -assisted strategy was used to synthesize Por-Fe,Co-NC as an electrocatalyst exhibiting improved oxygen reduction reaction (ORR) activity and MFC performance, demonstrating the effectiveness of transition-metal-based catalysts derived from metal–organic frameworks (MOFs). The Por-Fe,Co-NC electrocatalyst exhibited superior ORR performance, attributed to its high specific surface area, porous structure, and abundant exposure of catalytic active sites, compared to the non-SiO 2 -assisted catalyst (Fe,Co-NC). In addition, the Por-Fe,Co-NC was used as the cathode catalyst in an MFC device. The maximum power density and stable output voltage of Por-Fe,Co-NC MFC were 154.2 mW m –2 and 278 mV, respectively, which were better than those of Fe,Co-NC MFC. Por-Fe,Co-NC MFC showed a better COD removal efficiency of 92.91% in the anode solution, as well, much higher than 79.25% and 63.77% for Fe,Co-NC and graphite MFCs, respectively. This novel structure design represents a promising and informative paradigm for utilizing MOF-derived nanomaterials in the area of flexible and sustainable energy applications.