Hollow Zn/multi-heteroatom carbon polyhedra derived from ZIF-8 as efficient cathode catalysts for microbial fuel cells

Microbial fuel cells (MFCs) offer simultaneous wastewater treatment and energy generation, but their performance is limited by sluggish oxygen reduction reaction (ORR) kinetics at the cathode. To address this, we aimed to develop a low-cost, high-performance catalyst as an alternative to noble metals. We hypothesized that a hollow Zn/multi-heteroatom co-doped carbon structure derived from ZIF-8 could enhance ORR activity by improving active site exposure and charge transport. The catalyst was synthesized via template-guided structural transformation and optimized pyrolysis. The resulting Zn/DAFP-800 exhibited a high surface area (748.62 m 2  g −1 ), a Tafel slope of 71.24 mV dec −1 , and achieved a maximum power density of 2535.32 ± 7.64 mW m −2 in MFCs with 93.62 % retention over 30 days. Additionally, it achieved 92 % chemical oxygen demand (COD) removal in simulated industrial wastewater. These findings demonstrate the catalyst’s promise for practical applications in electrocatalysis and sustainable energy conversion systems.