Fish gills used to develop efficient low-cost electrocatalysts for rechargeable batteries

Fish gills used to develop efficient low-cost electro-catalysts for rechargeable metal-air battery

Scientists at the (INST), Mohali, an autonomous institute under the Department of Science and Technology, Govt. of India, have recently come up with an efficient, low-cost electro-catalyst from fish gills that can help develop environmentally friendly energy conversion devices.

This bio-inspired carbon nanostructure can help overcome the bottleneck in the realization of several conversion and technologies such as fuel cell, biofuel cell, and metal−air battery.

The present strategy enriches a route to synthesize low-cost, highly efficient bioinspired electrocatalyst that is better than commercial Platinum on carbon (Pt/C) catalyst and could be utilized as next-generation nonprecious carbon-based electrocatalyst for energy conversion and storage applications. The results have been recently published in the journal Inorganic Chemistry published by the American Chemical Society, 2020, (DOI: 10.1021/acs.inorgchem.0c00446).

Dr. Ramendra Sundar Dey and his team from INST have explored a highly active Oxygen Reduction Reaction (ORR) electrocatalyst based on binary transition metals Iron (Fe), and Manganese (Mn) and N-doped porous carbon (Fe, Mn, N-FGC), derived from fish gills (FG) acquired as animal waste, which has a unique porous structure and could provide conductive carbon networks after heat treatment and could be an efficient electrode material. The catalyst was able to show active oxygen reduction reaction in a wide range of pH (pH < 1, 7, and >13) and outperformed the commercial Pt/C catalyst.

They fabricated a homemade rechargeable Zn−air battery (ZAB) with the catalyst as an air cathode, which showed almost stable charge−discharge voltage plateaus after rigorous cycling for a long duration. It surpassed the commercial Pt/C based ZAB performance. The scientists found that the reason behind the outstanding performance of this catalyst is the presence of Fe−Mn based binary moiety, which is actually beneficial for the Oxygen (O2) binding and boosting Oxygen Reduction Reaction (ORR) catalytic performances in alkaline medium by weakening the Oxygen-Oxygen bonds.

The researchers have suggested that the careful selection of transition metals and heteroatoms together with engineering the synthesis protocol can pave a new way for exploring highly active low-cost electrocatalyst for efficient and environmentally friendly energy conversion devices.