物理化学学报 >> 2021, Vol. 37 >> Issue (7): 2009051.doi: 10.3866/PKU.WHXB202009051

所属专题: 电催化

论文 上一篇    下一篇

磷化钴封装在磷富集的三维多孔碳及其双功能氧电催化性能研究

肖瑶1,2, 裴煜2, 胡一帆2, 马汝广2, 王德义1,*(), 王家成2,*()   

  1. 1 西华大学理学院,成都 610039
    1 中国科学院上海硅酸盐研究所,高性能陶瓷与超微结构国家重点实验室,上海 200050
  • 收稿日期:2020-09-15 录用日期:2020-11-16 发布日期:2020-11-20
  • 通讯作者: 王德义,王家成 E-mail:deyi.wang@imdea.org;jiacheng.wang@mail.sic.ac.cn
  • 基金资助:
    上海市优秀学术带头人(青年)(20XD1424300)

Co2P@P-Doped 3D Porous Carbon for Bifunctional Oxygen Electrocatalysis

Yao Xiao1,2, Yu Pei2, Yifan Hu2, Ruguang Ma2, Deyi Wang1,*(), Jiacheng Wang2,*()   

  1. 1 School of Science, Xihua University, Chengdu 610039, China
    1 State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
  • Received:2020-09-15 Accepted:2020-11-16 Published:2020-11-20
  • Contact: Deyi Wang,Jiacheng Wang E-mail:deyi.wang@imdea.org;jiacheng.wang@mail.sic.ac.cn
  • About author:Email: jiacheng.wang@mail.sic.ac.cn (J.W.), Tel.: +86-21-52412714 (J.W.)
    Email:deyi.wang@imdea.org (D.W.), Tel.: +34-915493422 (D.W.)
  • Supported by:
    the Program of Shanghai Academic Research Leader(20XD1424300)

摘要:

能源和环境问题是制约人类延续和发展的首要问题,高效便宜的能源存储和转换装置吸引着广泛注意。基于便携式,功率密度高,无污染等,可充放电锌-空气电池(ZAB)被大量研究。然而,阴极的氧还原(ORR)和氧析出反应(OER)缓慢的动力学限制了ZAB的实际应用。开发电催化高效,便宜,高稳定性的双功能电催化剂至关重要,而其中将过渡金属和碳基材料复合是明智的决定。磷化钴(Co2P)化合物已经广泛研究用作高效的OER催化剂,但是对于催化剂的ORR活性很少研究。在此,本论文通过简单热处理钴盐和植酸掺杂的k-卡拉胶复合物制备出磷化钴封装在磷掺杂的多孔碳(Co2P-PCA-800)纳米催化剂。该催化剂具有3D分级多孔结构,表现出具有与商用Pt/C相当的半波电位(E1/2) 0.84 V,从而满足了可充放电锌-空电池需求。同时,我们还制备了磷掺杂的多孔碳(PCA)和钴掺杂的多空碳(Co-CA),对比了结构形貌对性能的影响。结果表明,具有完整的多孔结构,在每个位点的阻抗更一致,从而会有更多的有效活性位点。高效的ORR和OER活性主要归功于3D蜂窝分层多孔结构和正电荷磷化钴(Co2P)纳米颗粒的协同作用。此外,蜂窝状3D孔结构不仅利于传质和加快电子传输也保护了磷化钴,让其更稳定。最后,我们组装了可充放电锌-空气电池用Co2P-PCA-800作空气阴极催化剂。相比贵金属,该催化剂组装的ZAB具有接近的充放电性能和能量密度以及更高的比容量和更好的稳定性。这项工作也为解决能源和环境问题提供了新思路。

关键词: 磷化钴纳米颗粒, 三维多孔碳, 电催化, 氧还原反应, 锌空电池

Abstract:

The existing energy and environmental issues are the primary issues that restrict the continual development of the mankind. Cost-effective energy storage and conversion devices have attracted significant attention. Rechargeable zinc-air batteries (ZABs) are widely studied because they are portable, possess high power density, and are environmentally friendly. However, the slow kinetics of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) limit their practical application. It is crucial to develop dual-functional electrocatalysts with excellent electrocatalytic performance, low price, simple operation, and outstanding stability. Therefore, transition metals and carbon-based materials should be combined. Although Co2P has been widely reported as an efficient OER catalyst, there are few studies based on the ORR activity. Herein, a facile pyrolysis of cobalt salt, phytic acid, and k-carrageenan aerogel was carried out on Co2P nanoparticles within P-doped porous carbon (Co2P-PCA-800), showing enhanced ORR activity. The resulting composite (Co2P-PCA-800) with a three-dimensional (3D) hierarchical porous architecture exhibited outstanding ORR activity with a high half-wave potential (E1/2) of approximately 0.84 V, which is comparable to that of Pt/C. Simultaneously, we fabricated phosphorus-doped porous carbon (PCA) and cobalt-doped porous carbon (Co-CA) to compare the effect of structural morphology on the catalytic performance. Studies have found that a regular interconnected porous structure can be beneficial for mass transfer and can ensure uniform distribution of ion current, thereby resulting in increased number of effective active sites. The outstanding ORR activity mainly results from the synergistic effect of the 3D honeycomb hierarchical porous structure and positively charged Co2P nanoparticles encapsulated in P-doped carbon. In addition, the 3D honeycomb porous carbon structure not only facilitates mass transfer and accelerates electron transfer but also protects the cobalt phosphide. Finally, we assembled a rechargeable ZAB with Co2P-PCA-800 as the air cathode catalyst. Compared with precious metal catalysts, the catalyst has considerable charge-discharge performance and energy density as well as higher specific capacity and better cycle stability. We believe that this study will provide a significant direction for solving energy and environmental issues.

Key words: Co2P nanoparticles, 3D porous carbon, Electrocatalysis, Oxygen reduction reaction, Zn-air battery

MSC2000: 

  • O646