Facile synthesis of sewage sludge derived in situ multi doped nanoporous carbon material for electrocatalytic oxygen reduction
Developing efficient, low cost, and stable carbon based catalysts for oxygen reduction reaction (ORR) to replace the expensive platinum based electrocatalysts remains a major challenge that hamper the practical application of fuel cells. Here, we report that N, Fe, and S co doped nanoporous carbon material, derived via a facile one step pyrolysis of sewage sludge, the major byproduct of wastewater treatment, can serve as an effective electrocatalyst for ORR. Except for the comparable catalytic activity with commercial 20% Pt/C via a nearly four electron transfer pathway in both alkaline and acid medium, the as synthesized co doped electrocatalyst also exhibits excellent methanol crossover resistance and outstanding long term operation stability. The organic compounds in sewage sludge act as the carbon source and the in situ N and S dopant in the fabrication, while the inorganic compounds serve as the in built template and the in situ Fe dopant. Our protocol demonstrates a new approach in the economic and eco friendly benign reuse of sewage sludge, and also provides a straightforward route for synthesizing excellent carbon based electrocatalysts as promising candidates for ORR directly from a type of waste/pollution.
Scientific reports