物理化学学报 >> 2023, Vol. 39 >> Issue (9): 2212025.doi: 10.3866/PKU.WHXB202212025

所属专题: 多物理场能源催化转化

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微波热冲快速制备二维多孔La0.2Sr0.8CoO3钙钛矿用于高效电催化析氧反应

胡荣1, 韦丽云1, 鲜靖林1, 房光钰1, 吴植傲1, 樊淼1, 郭家越1, 李青翔1, 刘凯思1, 姜会钰1, 徐卫林1, 万骏1,*(), 姚永刚2,*()   

  1. 1 武汉纺织大学, 省部共建纺织新材料与先进加工技术国家重点实验室, 生物质纤维与生态染整湖北省重点实验室, 武汉 430200
    2 华中科技大学, 材料加工与模具技术国家重点实验室, 材料科学与工程学院, 武汉 430074
  • 收稿日期:2022-12-16 录用日期:2023-01-25 发布日期:2023-04-03
  • 通讯作者: 万骏,姚永刚 E-mail:wanj@wtu.edu.cn;yaoyg@hust.edu.cn
  • 作者简介:第一联系人:

    These authors contributed equally to the work.

Microwave Shock Process for Rapid Synthesis of 2D Porous La0.2Sr0.8CoO3 Perovskite as an Efficient Oxygen Evolution Reaction Catalyst

Rong Hu1, Liyun Wei1, Jinglin Xian1, Guangyu Fang1, Zhiao Wu1, Miao Fan1, Jiayue Guo1, Qingxiang Li1, Kaisi Liu1, Huiyu Jiang1, Weilin Xu1, Jun Wan1,*(), Yonggang Yao2,*()   

  1. 1 State Key Laboratory of New Textile Materials and Advanced Processing Technologies, Hubei Key Laboratory of Biomass Fibers and Eco-Dyeing & Finishing, Wuhan Textile University, Wuhan 430200, China
    2 State Key Laboratory of Materials Processing and Die and Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
  • Received:2022-12-16 Accepted:2023-01-25 Published:2023-04-03
  • Contact: Jun Wan, Yonggang Yao E-mail:wanj@wtu.edu.cn;yaoyg@hust.edu.cn

摘要:

析氧反应(OER)被认为是电解水的关键限制步骤,已被广泛作为清洁能源方式用于解决能源和环境问题。钙钛矿氧化物(ABO3)具有可调的电子结构、高灵活性的元素组成,能在OER中表现出良好的催化活性。然而,钙钛矿氧化物的合成通常需要经历长时间的高温,极易导致金属的聚集和影响材料的本征活性。气相微波技术可以显著缩短热处理时间,从而减少相关的碳排放。这项技术不仅解决了对碳中性过程日益增长的需求,而且还增加了对合成的控制,以避免产品的不良团聚。本文采用微波热冲法快速制备了二维(2D)多孔La0.2Sr0.8CoO3钙钛矿。伴随微波过程的快速熵增可以有效地暴露La0.2Sr0.8CoO3结构中丰富的活性位点。此外,高能微波冲击过程可以精准地将Sr2+引入到LaCoO3的晶格中,通过增加Co的氧化态来增加氧空位量。这种锶元素取代镧引入的氧空位能极大提高催化剂的本征催化活性。对于碱性电解液中的OER应用,制备的La0.2Sr0.8CoO3在10 mA∙cm−2下展现出了360 mV的过电位,Tafel斜率为76.6 mV∙dec−1。且在经历30000秒的长时间循环测试后仍能维持初始电流密度的97%。这项研究为高活性二维钙钛矿的合成提供了一种简便、快速的策略。

关键词: 二维, 钙钛矿, 微波, 氧缺陷, 析氧反应

Abstract:

The oxygen evolution reaction (OER) is considered the rate-limiting step in electrochemical water splitting, and has been widely used to solve energy and environmental issues. Perovskite oxides (ABO3) exhibit good OER activity, owing to their tunable electronic structures and highly flexible elemental compositions. However, the preparation of perovskite oxides usually requires long exposure to high temperatures, resulting in metal agglomeration and undesirable effects on intrinsic activity. Vapor-phase microwave technology can significantly reduce the duration of heat treatment and subsequently reduce the associated carbon emissions. This technology not only addresses the growing demand for carbon-neutral processes but also enables increased control of the synthesis to avoid undesirable agglomeration of the product. In this study, a 2D porous La0.2Sr0.8CoO3 perovskite was rapidly prepared using a microwave shock method. The rapid entropy increase associated with the microwave process can effectively expose abundant active sites in the La0.2Sr0.8CoO3 structure. Furthermore, the high-energy microwave shock process can precisely introduce Sr2+ into the lattice of LaCoO3, increasing the number of oxygen vacancies by increasing the oxidation state of Co. The oxygen vacancies introduced by replacing La with Sr can considerably improve the intrinsic catalytic activity of the material. For the OER in alkaline electrolytes, the prepared La0.2Sr0.8CoO3 catalyst displayed an excellent overpotential of 360 mV at 10 mA·cm−2 and a Tafel slope of 76.6 mV·dec−1. After a long-term cycle test of 30000 s, 97% of the initial current density was maintained. This study presents a facile and rapid strategy for the synthesis of highly active 2D perovskites.

Key words: Two-dimensional, Perovskite, Microwave, Oxygen vacancy, Oxygen evolution reaction