Polyoxometalate@ZIF Induced CoWO4/WS2@C-N Nanoflower as a Highly Efficient Catalyst for Zn–Air Batteries
Polyoxometalate@ZIF Induced CoWO4/WS2@C-N Nanoflower as a Highly Efficient Catalyst for Zn–Air Batteries
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DOI：
10.1021/acsaem.1c01000
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发表时间：
2021-07
影响因子：
6.4
通讯作者：
Di Yin;Mingliang Wang;Yundong Cao;Xiaopeng Yang;Sugueun Ji;Hui-Ping Hao;Guang-gang Gao;Lin-lin F
中科院分区：
文献类型：
--
作者：
Di Yin;Mingliang Wang;Yundong Cao;Xiaopeng Yang;Sugueun Ji;Hui-Ping Hao;Guang-gang Gao;Lin-lin F
It is crucial to cultivate competent and stable bifunctional electrocatalysts for both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). In this work, a high-performance and long-lasting electrocatalyst of CoWO4/WS2@C-N nanocomposite with the unique hierarchical flowerlike superstructure is achieved by sulfuration of porous polyoxometalate@ZIF-67 precursor, in which the polyoxometalate acts as both template and acidic etching agent. The introduction of polyoxometalate also plays a key role in forming the binary CoWO4/WS2active center during the sulfuration process. CoWO4/WS2@C-N electrocatalyst shows higher electrocatalytic activity than commercial noble-metal catalysts under the same conditions. DFT calculations indicate that both the high adsorption energy for the OH–group and low adsorption energy for O2on the surface of CoWO4/WS2sites result in high OER and ORR activity. When CoWO4/WS2@C-N is assembled in a lab-made Zn–air battery as cathode material, the battery shows a higher discharge plateau voltage of 1.46 V and a specific capacity of 664 mA h gZn–1, the behavior of which is comparable to the reported non-noble-metal materials. The synthetic strategy presented in this work not only opens a polyoxometalate-etching-ZIF way to constructing a nanosized heterojunction catalyst but also provides a cost-effective and robust electrocatalyst potentially used in practical Zn–air batteries.
