RETRACTED: Manganese enriched zeolitic imidazole framework-67 and doped reduced graphene oxide hybrid electrocatalyst applied in alkaline Zn-air battery

Year: 2025

Type: article

Abstract: • MnZIF/SN-rGO catalyst shows superior ORR activity with ∼4e - transfer and low H₂O₂. • Novel use of Pumped MD/SC mode of SECM in alkaline media to map ORR activity. • MnZIF/SN-rGO retains activity after 1000 CV cycles with minimal performance loss. • Gel Zn–air battery delivers 955 mAh·g - ¹Zn and 1336 mWh·g - ¹Zn with 32 h discharge. • MnZIF/SN-rGO shows higher specific capacity than state-of-art cathodes. The development of durable, low-cost electrocatalysts for the oxygen reduction reaction (ORR) is crucial to the advancement of Zn–air batteries. Here different zeolitic imidazolium framework (ZIF-67)-based hybrid electrocatalysts supported on reduced graphene oxide (rGO) are evaluated (ZIF/rGO, ZIF/SN-rGO, and MnZIF/SN-rGO) for the ORR in alkaline media and gel Zn–air batteries. A key feature of this work is the application of pumped-micropipette delivery/substrate-collection (pumped-MD/SC) mode of scanning electrochemical microscopy (SECM) in alkaline electrolyte, a mode rarely explored and, to the best of our knowledge, not previously reported for ORR mapping under these conditions. Pumped-MD/SC SECM current maps unambiguously identify MnZIF/SN-rGO as the most active electrocatalytic material, showing the lowest overpotential, as well as exhibiting the highest limiting current and negligible H₂O₂ yield evaluated by rotating ring-disc electrode (RRDE). The catalyst retains its activity after 1000 potential cycles under ORR conditions, evidencing excellent durability. When implemented as the air-cathode in a non-rechargeable gel Zn–air battery, MnZIF/SN-rGO delivers a specific capacity of 803 mAh g - ¹ Zn and a specific energy of 1119 mWh g - ¹ Zn , sustaining a stable discharge > 1.4 V for 32 h at 10 mA cm - ². These metrics surpass most gel-electrolyte Zn–air batteries reported under comparable conditions, highlighting the practical relevance of the catalyst. The combined SECM–battery approach links spatially resolved ORR activity with device-level performance, providing mechanistic insight and a robust benchmark for future cathode design. Overall, MnZIF/SN-rGO emerges as a highly durable and efficient cathode for gel Zn–air batteries.

Source: Chemical Engineering Journal Advances

DOI: 10.1016/j.ceja.2025.100999

Authors: S. Fajardo, C.M. Sánchez-Sánchez, P. Ocón, J.L. Rodríguez, E. Pastor

Institutions: Centre National de la Recherche Scientifique, Universidad de La Laguna, Sorbonne Université, Laboratoire Interfaces et Systèmes Électrochimiques, Universidad Autónoma de Madrid

Language: English

Topic: Electrocatalysts for Energy Conversion

Subfield: Renewable Energy, Sustainability and the Environment

Field: Energy

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: gold

Estimated APC paid: $2,050