材料科学
双功能
碳纳米管
电催化剂
催化作用
甲醇
金属
化学工程
电化学
核化学
纳米技术
电极
物理化学
有机化学
化学
冶金
工程类
作者
Siqi Zhao,Deliang Chen,Yawu Gao,Tao Li,Shasha Yi,Haipeng Ji,Xiaochao Zuo,Yu Wang,Zhongtao Zhang,Rui Zhang,Huaming Yang
出处
期刊:NANO
[World Scientific]
日期:2021-02-16
卷期号:16 (03): 2150028-2150028
被引量:5
标识
DOI:10.1142/s1793292021500284
摘要
Novel synthesis of efficient noble-metal-free electrocatalysts for both oxygen reduction/evolution reaction (ORR/OER) in energy conversion devices (e.g., fuel cells, metal–air batteries) is of essential significance for further sustainable development. This paper reports a facile synthesis of Fe–N–C species-modified carbon nanotubes (F/N-CNTs) for ORR application by directly pyrolyzing a fluffy hybrid precursor at a moderate temperature ([Formula: see text]C) in Ar. The fluffy hybrid precursors consisting of nitro-hydrochloric-acid-treated CNTs, melamine and Fe[Formula: see text] species are prepared via a freeze-drying method. On account of the synergistic effect of various active sites, including pyridine–N, Fe–N x and Fe 3 C, and the high conductivity of the CNTs matrix, the as-obtained F/N-CNT electrocatalysts exhibit excellent ORR activities, comparable to commercial Pt/C. The addition of N heteroatoms, the dosage of Fe and the pyrolysis temperature highly influence the ORR properties of the F/N-CNT samples. The typical F/N-CNT sample obtained at the optimized parameters shows an onset potential of 1.06[Formula: see text]V and a half-wave potential of 0.91[Formula: see text]V versus reversible hydrogen electrode (RHE) in an alkaline condition, more positive than those (1.01[Formula: see text]V and 0.88[Formula: see text]V versus RHE) of Pt/C. The F/N-CNT exhibits outstanding bifunctional ORR/OER activity and excellent methanol tolerance, and the F/N-CNT-based Zn–air battery (ZAB) with an open-circuit voltage (OCV) of 1.405[Formula: see text]V presents a current density of 125[Formula: see text]mA[Formula: see text]cm[Formula: see text] and a power density of 76.5[Formula: see text]mW[Formula: see text]cm[Formula: see text]; these electrocatalytic properties are highly superior to Pt/C. The direct pyrolysis of fluffy hybrid precursors provides a concise but robust technical platform to achieve high-performance noble-metal-free electrocatalysts with ORR/OER activities superior to Pt/C.
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