Abstract
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.
Highlights
Sanitation engineering[19,20]
In this study we demonstrate the synthesis of multi-doped nanoporous carbon materials, as efficient electrocatalysts for ORR in both alkaline and acid medium, from sewage sludge via a facile, low-cost, and scalable pyrolysis approach without any activation
It can be concluded that the pyrolysis process causes the in-situ N, Fe, and S self-doped into the carbon framework of the as-synthesized catalyst, and leads to the formation of pyridinic and quaternary N species and thiophene-S species which act as the electrocatalytic active sites[13,14,26]
Summary
Sanitation engineering[19,20]. The need to develop a method of reusing sewage sludge that is economically, socially, and environmentally sustainable is of particular concern. Sludge pyrolysis can convert approximately half of the organic matter in sewage sludge into renewable liquid fuels and chemical feedstock, and immobilize the remainder and the inorganic matter into a stabilized form of pyrolytic residue (biochar)[21,22]. This residue, a carbonaceous matrix byproduct containing various heteroatoms (N, S, Fe, etc.), is generally recognized as an alternative adsorbent[23]. In this study we demonstrate the synthesis of multi-doped nanoporous carbon materials, as efficient electrocatalysts for ORR in both alkaline and acid medium, from sewage sludge via a facile, low-cost, and scalable pyrolysis approach without any activation. Our protocol reveals a new approach for the value-added reuse of sewage sludge, and confirms its true potential as a candidate for the synthesis of multi-doped nanoporous carbon material as a highly active ORR catalyst
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
