Zhang Jiting, Zhang Meng, Zeng Yan, Chen Jisheng, Qiu Lingxi, Zhou Hua, Sun Chengjun, Yu Ying, Zhu Chengzhou, Zhu Zhihong
Institute of Nano-Science and Nano-Technology, College of Physical Science and Technology, Central China Normal University, Wuhan, 430079, China.
Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensing Technology and Health, College of Chemistry, Central China Normal University, Wuhan, 430079, P. R. China.
Small. 2019 Jun;15(24):e1900307. doi: 10.1002/smll.201900307. Epub 2019 May 6.
Iron-nitrogen-carbon materials (Fe-N-C) are known for their excellent oxygen reduction reaction (ORR) performance. Unfortunately, they generally show a laggard oxygen evolution reaction (OER) activity, which results in a lethargic charging performance in rechargeable Zn-air batteries. Here porous S-doped Fe-N-C nanosheets are innovatively synthesized utilizing a scalable FeCl -encapsulated-porphyra precursor pyrolysis strategy. The obtained electrocatalyst exhibits ultrahigh ORR activity (E = 0.84 V vs reversible hydrogen electrode) and impressive OER performance (E = 1.64 V). The potential gap (ΔE = E - E ) is 0.80 V, outperforming that of most highly active bifunctional electrocatalysts reported to date. Furthermore, the key role of S involved in the atomically dispersed Fe-Nx species on the enhanced ORR and OER activities is expounded for the first time by ultrasound-assisted extraction of the exclusive S source (taurine) from porphyra. Moreover, the assembled rechargeable Zn-air battery comprising this bifunctional electrocatalyst exhibits higher power density (225.1 mW cm ) and lower charging-discharging overpotential (1.00 V, 100 mA cm compared to Pt/C + RuO catalyst). The design strategy can expand the utilization of earth-abundant biomaterial-derived catalysts, and the mechanism investigations of S doping on the structure-activity relationship can inspire the progress of other functional electrocatalysts.
铁氮碳材料（Fe-N-C）以其优异的氧还原反应（ORR）性能而闻名。不幸的是，它们通常表现出滞后的析氧反应（OER）活性，这导致可充电锌空气电池的充电性能不佳。在此，利用可扩展的FeCl封装紫菜前驱体热解策略创新性地合成了多孔硫掺杂Fe-N-C纳米片。所获得的电催化剂表现出超高的ORR活性（相对于可逆氢电极，E = 0.84 V）和令人印象深刻的OER性能（E = 1.64 V）。电位差（ΔE = E - E）为0.80 V，优于迄今为止报道的大多数高活性双功能电催化剂。此外，首次通过超声辅助从紫菜中提取唯一的硫源（牛磺酸），阐述了原子分散的Fe-Nx物种中硫对增强ORR和OER活性的关键作用。此外，包含这种双功能电催化剂的组装可充电锌空气电池表现出更高的功率密度（225.1 mW cm）和更低的充放电过电位（1.00 V，100 mA cm，与Pt/C + RuO催化剂相比）。该设计策略可以扩大对地球上储量丰富的生物材料衍生催化剂的利用，并且硫掺杂对结构-活性关系的机理研究可以激发其他功能电催化剂的进展。
