Topological defect and sp3/sp2 carbon interface derived from ZIF-8 with linker vacancies for oxygen reduction reaction

Haixing Gao, Shuo Wang, Weng-Chon (Max) Cheong, Kaixi Wang, Huifang Xu, Aijian Huang, Junguo Ma, Jiazhan Li, Weng-Fai (Andy) Ip, Kwan San Hui, Duc Anh Dinh, Xi Fan, Feng Bin, Fuming Chen, Kwun Nam Hui

Research output: Contribution to journalArticlepeer-review

Abstract

Defects in nanocarbon materials can trigger their intriguing electrochemical properties and potential applications, but their synthesis is challenging. Herein, we report the synthesis of ultrathin nitrogen-doped carbon nanosheets with intrinsic defects through the pyrolysis of ZIF-8 with linker vacancies. The as-synthesized electrocatalyst exhibits excellent oxygen reduction reaction (ORR) activity with an onset potential and half-wave potential of 1.05 and 0.873 V vs. RHE, respectively, outperforming the reported metal-free ORR electrocatalysts. It also shows a commercial Pt/C-comparable performance in zinc–air battery with a power density of 154.4 mW cm−2. Characterization and DFT calculation results suggest the adjacent sp3-carbon in carbon pentagon can significantly strengthen the adsorption and activation of oxygen molecules on sp2-carbon, hence the potential determining step is altered and ORR overpotential is lowered. This work highlights a promising green synthesis strategy of MOF-derived metal-free nanocarbon materials for wide application in advanced energy technologies.
Original languageEnglish
Pages (from-to)76-87
Number of pages12
JournalCarbon
Volume203
Early online date19 Oct 2022
DOIs
Publication statusE-pub ahead of print - 19 Oct 2022

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