Department of Mechanical and Materials Engineering, University of Western Ontario , London, Ontario N6A 5B9, Canada.
ACS Appl Mater Interfaces. 2017 Sep 20;9(37):31841-31852. doi: 10.1021/acsami.7b08647. Epub 2017 Sep 5.
Aluminum-air battery is a promising candidate for large-scale energy applications because of its low cost and high energy density. Remarkably, tremendous efforts have been concentrated on developing efficient and stable cathode electrocatalysts toward the oxygen reduction reaction. In this work, a hydrothermal-calcination approach was utilized to prepare novel reduced graphene oxide (rGO)-supported hollow ZnO/ZnCoO nanoparticle-embedded carbon nanocages (ZnO/ZnCoO/C@rGO) using a zeolitic imidazolate framework (ZIF-67)/graphene oxide/zinc nitrate composite as the precursor. The ZnO/ZnCoO/C@rGO hybrid exhibits remarkable electrocatalytic performance for oxygen reduction reaction under alkaline conditions and superior stability and methanol tolerance to those of the commercial Pt/C catalyst. Furthermore, novel and simple Al-air coin cells were first fabricated using the hybrid materials as cathode catalysts under ambient air conditions to further investigate their catalytic performance. The coin cell with the ZnO/ZnCoO/C@rGO cathode catalyst displays a higher open circuit voltage and discharge voltage and more sluggish potential drop than those of the cell with the ZnO/ZnCoO/C cathode catalyst, which confirms that rGO can enhance the electrocatalytic activity and stability of the catalyst system. The excellent electrocatalytic performance of the ZnO/ZnCoO/C@rGO hybrid is attributed to the prominent conductivity and high specific surface area resulting from rGO, the more accessible catalytic active sites induced by the unique porous hollow nanocage structure, and synergic covalent coupling between rGO sheets and ZnO/ZnCoO/C nanocages.
铝空气电池因其成本低、能量密度高而成为大规模能源应用的有前途的候选者。值得注意的是，人们已经集中精力开发高效稳定的阴极电催化剂，以实现氧还原反应。在这项工作中，采用水热-煅烧方法，以沸石咪唑酯骨架（ZIF-67）/氧化石墨烯/硝酸锌复合为前驱体，制备了新型还原氧化石墨烯（rGO）负载的空心 ZnO/ZnCoO 纳米颗粒嵌入碳纳米笼（ZnO/ZnCoO/C@rGO）。ZnO/ZnCoO/C@rGO 杂化物在碱性条件下对氧还原反应表现出显著的电催化性能，并且具有比商业 Pt/C 催化剂更高的稳定性和甲醇耐受性。此外，首次使用混合材料作为阴极催化剂在环境空气中制备了新型简单的 Al-空气扣式电池，以进一步研究其催化性能。使用 ZnO/ZnCoO/C@rGO 阴极催化剂的扣式电池具有比使用 ZnO/ZnCoO/C 阴极催化剂更高的开路电压和放电电压，以及更缓慢的电位降，这证实了 rGO 可以增强催化剂体系的电催化活性和稳定性。ZnO/ZnCoO/C@rGO 杂化物具有优异的电催化性能，归因于 rGO 带来的突出导电性和高比表面积、独特的多孔空心纳米笼结构引起的更易接近的催化活性位点以及 rGO 片和 ZnO/ZnCoO/C 纳米笼之间的协同共价偶联。
