Ionic liquid modified graphene nanosheets anchoring manganese oxide nanoparticles as efficient electrocatalysts for Zn-air batteries
Ionic liquid modified graphene nanosheets anchoring manganese oxide nanoparticles as efficient electrocatalysts for Zn-air batteries
复制标题
DOI：
10.1039/c1ee01942b
复制
发表时间：
2011-10-01
影响因子：
32.5
通讯作者：
Kim, Byeong-Su
中科院分区：
文献类型：
--
作者：
Lee, Jang-Soo;Lee, Taemin;Kim, Byeong-Su
通过简单的基于溶液的生长机制合成了离子液体（IL）修饰的还原氧化石墨烯（rGO-IL）纳米片锚定氧化锰（Mn 3 O 4），并将其应用于锌空气电池作为有效的氧还原反应（ORR）电催化剂。在这项研究中，在这些复合材料中的IL部分不仅增加了系统的导电性，而且与原始rGO相比，还增加了电催化活性，以及促进ORR与Mn 3 O 4的固有催化活性的协同效应。基于Koutecky-Levich图，我们认为这些复合材料的ORR途径是可调的，与负载在石墨烯片上的Mn 3 O 4纳米颗粒的相对量有关;例如，具有较低Mn 3 O 4（19.2%）纳米颗粒含量的系统的ORR机制与Pt/C电极类似，即，一个一步，准4电子转移，不像与较高的Mn 3 O 4（52.5%）的含量，这经历了经典的两步，2电子途径。我们还证明了这些混合rGO-IL/Mn 3 O 4纳米颗粒作为锌-空气电池中ORR的有效催化剂的潜力，其最大峰值功率密度为120 mW cm（-2）;比商业阴极催化剂的性能更高。
Ionic liquid (IL) modified reduced graphene oxide (rGO-IL) nanosheets anchoring manganese oxide (Mn3O4) are synthesized via a facile solution-based growth mechanism and applied to a Zn-air battery as an effective electrocatalyst for the oxygen reduction reaction (ORR). In this study, the IL moiety in these composites increases not only the conductivity of the system, but also the electrocatalytic activity compared to pristine rGO, together with the synergic effect of facilitating the ORR with the intrinsic catalytic activity of Mn3O4. Based on the Koutecky-Levich plot, we suggest that the ORR pathway of these composites is tunable with the relative amount of Mn3O4 nanoparticles supported onto the graphene sheets; for example, the ORR mechanism of the system with a lower Mn3O4 (19.2%) nanoparticle content is similar to a Pt/C electrode, i.e., a one-step, quasi-4-electron transfer, unlike that with a higher Mn3O4 (52.5%) content, which undergoes a classical two-step, 2-electron pathway. We also demonstrate the potential of these hybrid rGO-IL/Mn3O4 nanoparticles as efficient catalysts for the ORR in the Zn-air battery with a maximum peak power density of 120 mW cm(-2); a higher performance than that from commercial cathode catalysts.