Bacterial cellulose derived nitrogen-doped carbon nanofiber aerogel: An efficient metal-free oxygen reduction electrocatalyst for zinc-air battery
Bacterial cellulose derived nitrogen-doped carbon nanofiber aerogel: An efficient metal-free oxygen reduction electrocatalyst for zinc-air battery
复制标题
细菌纤维素衍生的氮掺杂碳纳米纤维气凝胶：一种用于锌空气电池的高效无金属氧还原电催化剂
DOI：
10.1016/j.nanoen.2014.11.008
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发表时间：
2015-01-01
期刊：
影响因子：
17.6
通讯作者：
Yu, Shu-Hong
中科院分区：
文献类型：
--
作者：
Liang, Hai-Wei;Wu, Zhen-Yu;Yu, Shu-Hong
燃料电池和金属-空气电池中用于氧还原反应（ORR）的铂基电催化剂的昂贵和稀缺极大地阻碍了这些清洁能源技术的商业化。在这里，我们开发了一种高活性的氮掺杂碳纳米管（N-CNF）气凝胶无金属ORR电催化剂，其通过直接热解廉价的、绿色的和可批量生产的生物质来制备，即，细菌纤维素，然后NH3活化。N-CNF气凝胶继承了细菌纤维素的三维纳米纤维网络，同时具有高密度的含氮活性中心（5.8at%）和高BET表面积（916 m2/g）。这种N-CNF气凝胶在碱性介质中显示出上级的ORR活性（相对于可逆氢电极的半波电位为0.80 V）和高选择性（在0.8 V下的电子转移数为3.97），以及优异的电化学稳定性（在10，000次电位循环后半波电位仅负移20 mV）。N-CNF气凝胶的ORR活性超过NH3处理的炭黑、碳纳米管以及还原的氧化石墨烯气凝胶的ORR活性，以及大多数报道的无金属催化剂的ORR活性。重要的是，当用作构建锌-空气电池的空气电极的阴极催化剂时，N-CNF气凝胶在1.0和10 mA cm（-2）的放电电流密度下分别表现出1.34和1.25 V的高电压，这与现有技术的Pt/C催化剂高度可比（20重量% Pt，BASF），表明这种无金属催化剂作为碱性燃料电池和金属-空气电池的Pt/C的有前途的替代物的巨大潜力。(C)2014爱思唯尔有限公司版权所有。
The prohibitive cost and scarcity of the platinum-based eletrocatalysts for oxygen reduction reaction (ORR) in fuel cells and metal-air batteries hamper dramatically the commercialization of theses clean-energy technologies. Here, we develop a highly active nitrogen-doped carbon nanofiber (N-CNF) aerogel metal-free ORR electrocatalyst, prepared by direct pyrolysis of a cheap, green, and mass-producible biomass, i.e., bacterial cellulose, followed by NH3 activation. The N-CNF aerogel inherits the three-dimensional nanofibrous network of bacterial cellulose and meanwhile possess high density of N-containing active sites (5.8 at%) and high BET surface area (916 m(2)/g). Such N-CNF aerogel shows superior ORR activity (half-wave potential of 0.80 V versus reversible hydrogen electrode) and high selectivity (electron-transfer number of 3.97 at 0.8 V), and excellent electrochemical stability (only 20 mV negative shift of half-wave potential after 10,000 potential cycles) in alkaline media. The ORR activity of N-CNF aerogel exceeds that of NH3-treated carbon blacks, carbon nanotubes as well as reduced graphene oxide aerogels, and that of most reported metal-free catalysts. Importantly, when used as a cathode catalyst for constructing the air electrode of Zn-air battery, the N-CNF aerogel exhibits high voltages of 1.34 and 1.25 V at the discharge current densities of 1.0 and 10 mA cm(-2), respectively, which are highly comparable with the state-of-the art Pt/C catalyst (20 wt% Pt, BASF), indicating the great potential of this metal-free catalyst as a promising alternative to the Pt/C for alkaline fuel cells and metal-air batteries. (C) 2014 Elsevier Ltd. All rights reserved.