Nanofiber-based Sm0.5Sr0.5Co0.2Fe0.8O3-δ/N-MWCNT composites as an efficient bifunctional electrocatalyst towards OER/ORR

It is of significance to search non-noble metal OER/ORR catalysts with perfect performance. The introduction of carbon into perovskite can significantly enhance oxygen electro-catalytic activity. Herein, nanofiber-based Sm0.5Sr0.5Co0.2Fe0.8O3-d/rGO (SSCF28/rGO) and Sm0.5Sr0.5Co0.2Fe0.8O3-d/N-MWCNT (SSCF28/N-MWCNT) hybrids with various mass ratios were synthesized successfully by a facile ultrasonic mixing method and their oxygen evolution reaction (OER)/oxygen reduction reaction (ORR) properties were compared and studied. In 0.1 M KOH, SSCF28/N-MWCNT = 1.3 with optimal mass ratio shows better OER/ OER bifuntional catalytic activity than SSCF28/rGO = 2:1. After 1000 CV cycles, SSCF28/N-MWCNT = 1.3 remains stable. Compared to SSCF28/rGO = 2:1, SSCF28/N-MWCNT = 1:3 shows promising practical applicability in metal-air batteries. The excellent OER/ORR ac-tivity of SSCF28/N-MWCNT = 1:3 can be attributed to the component optimization of perovskite and carbon and the synergistic effect between nanofiber-structured SSCF28 and N-functionalized MWCNT (N-MWCNT).(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

The search for non-noble metal OER/ORR catalysts with excellent performance is of great significance. Introducing carbon into perovskite can significantly enhance oxygen electro-catalytic activity. In this study, nanofiber-based Sm0.5Sr0.5Co0.2Fe0.8O3-d/rGO and Sm0.5Sr0.5Co0.2Fe0.8O3-d/N-MWCNT hybrids were synthesized successfully and compared for their OER/ORR properties. SSCF28/N-MWCNT = 1.3 showed better catalytic activity than SSCF28/rGO = 2:1 in 0.1 M KOH. The optimized mass ratio of 1.3 remained stable after 1000 CV cycles and showed promising applicability in metal-air batteries. The excellent OER/ORR activity of SSCF28/N-MWCNT = 1:3 can be attributed to the component optimization of perovskite and carbon, as well as the synergistic effect between nanofiber-structured SSCF28 and N-functionalized MWCNT (N-MWCNT).