Highly Dispersed Co-, N-, S-Doped Topological Defect-Rich Hollow Carbon Nanoboxes as Superior Bifunctional Oxygen Electrocatalysts for Rechargeable Zn-Air Batteries
Highly Dispersed Co-, N-, S-Doped Topological Defect-Rich Hollow Carbon Nanoboxes as Superior Bifunctional Oxygen Electrocatalysts for Rechargeable Zn-Air Batteries
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高度分散的钴、氮、硫掺杂的富含拓扑缺陷的空心碳纳米盒作为可充电锌空气电池的优质双功能氧电催化剂
DOI：
10.1021/acsami.2c04030
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发表时间：
2022
影响因子：
9.5
通讯作者：
苏坤梅
中科院分区：
文献类型：
--
作者：
王明稳;曹磊;杜玺;张马亮;李振环;苏坤梅
锌空气二次电池由于其无毒、安全、高能量密度等优点而受到广泛关注。然而，锌-空气电池空气电极处的氧还原反应（ORR）和析氧反应（OER）都受到缓慢动力学的影响，限制了其商业化发展。本文以聚苯硫醚（PPS）为富硫碳源，制备了富含拓扑缺陷的Co、N、S共掺杂中空碳纳米盒（Co-N/S-CNBs）。关键是，通过利用自蔓延高温合成（SHS），PPS可以避免熔化，同时使催化剂呈现独特的中空结构。引入Co和N原子作为活性中心的额外后处理进一步增加了催化剂的缺陷位点和微孔结构。在碱性电解液中，Co-N/S-CNB使锌-空气电池表现出优异的ORR和OER双功能催化活性，超过了商业催化剂。化学分析表明，PPS在热解过程中小分子的裂解损失是形成拓扑缺陷的主要原因，这些缺陷位作为活性中心提高了催化性能。总的来说，这项工作提供了新的见解，在这样的催化剂中如何形成缺陷的机制，以及显示如何高性能的双功能电催化剂可以用于实际的锌-空气电池。
Rechargeable Zn-air batteries have received extensive attention due to their use of nontoxic materials, safety, and high energy density. However, the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) at the air electrode of Zn-air batteries both suffer from slow kinetics, limiting their commercialization development. Herein, we prepared Co, N, and S co-doped hollow carbon nanoboxes (Co-N/S-CNBs) rich in topological defects using polyphenylene sulfide (PPS) as a sulfur-rich carbon source. Critically, by utilizing the self-propagating high-temperature synthesis (SHS), PPS can avoid melting, while simultaneously enabling the catalyst to take on a unique hollow structure. Additional post-treatment to introduce Co and N atoms as active centers further increases the defect sites and microporous structures of the catalyst. Under alkaline electrolytes, the Co-N/S-CNBs enabled Zn-air batteries to exhibit excellent bifunctional catalytic activity for both ORR and OER, surpassing commercial catalysts. Chemical analysis showed that the cracking loss of small molecules from PPS during pyrolysis is the main reason for the formation of topological defects, where the defect sites act as active centers to enhance the catalytic performance. Overall, this work provides new insights into the mechanism of how defects are formed in such a catalyst, as well as shows how a high-performance bifunctional electrocatalyst can be utilized for practical Zn-air batteries.