Zhang Guoteng, Hao Zaitao, Yin Jie, Wang Chen, Zhang Jinghao, Zhao Zhiyu, Wei Denghu, Zhou Huawei, Li Zhongcheng
College of Materials Science and Engineering, School of Chemistry and Chemical Engineering, Shandong Provincial Key Laboratory/Collaborative Innovation Center of Chemical Energy Storage, Liaocheng University, China.
Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science, MOE, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, China.
Dalton Trans. 2020 Jul 21;49(28):9804-9810. doi: 10.1039/d0dt01660h.
The control of surface elements and nanostructures is one of the effective ways to design and synthesize high performance catalysts. Herein, we, for the first time, prepare FeS2 crystal lattices on WS2 nanosheets (FeS2 CL@WS2 NS) by solvothermal methods for the oxygen evolution reaction (OER). The FeS2 CLs effectively prevent the oxidation and aggregation of WS2 nanosheets and increase the electrochemically active surface area. The abundant surface defect in the FeS2 CL@WS2 NS electrocatalyst reduces the stress between the crystal lattices of FeS2 and that of WS2. The overpotential (260 mV) of the FeS2 CL@WS2 NS electrocatalyst for the OER at a current density of 10 mA cm-2 is superior to those of WS2 NS/Ni foam (310 mV) and IrO2/Ni foam (300 mV) in 1.0 M KOH solution. An electrochemical-kinetic study shows that the Tafel slope of 54 mV per decade for the FeS2 CL@WS2 NS electrocatalyst is lower than those of WS2 NS (102 mV per decade) and IrO2/Ni foam (77 mV per decade). In addition, the charge transport resistor (2.3 Ω) of the FeS2 CL@WS2 NS electrocatalyst for the OER is smaller than that of WS2 NS. These faster kinetic properties, in turn, explain the high catalytic activity of the FeS2 CL@WS2 NS electrocatalyst for the OER. The XPS and HRTEM results of the post stability sample confirm that Fe2+ and W4+ are oxidized after durability measurement. Thus, we think that the FeS2 CL@WS2 NS electrocatalyst is a promising candidate for efficient, low-cost, and stable non-noble-metal-based OER electrocatalysts.
控制表面元素和纳米结构是设计和合成高性能催化剂的有效方法之一。在此，我们首次通过溶剂热法在WS2纳米片（FeS2 CL@WS2 NS）上制备用于析氧反应（OER）的FeS2晶格。FeS2晶格有效地防止了WS2纳米片的氧化和聚集，并增加了电化学活性表面积。FeS2 CL@WS2 NS电催化剂中丰富的表面缺陷降低了FeS2和WS2晶格之间的应力。在1.0 M KOH溶液中，FeS2 CL@WS2 NS电催化剂在电流密度为10 mA cm-2时的OER过电位（260 mV）优于WS2 NS/泡沫镍（310 mV）和IrO2/泡沫镍（300 mV）。电化学动力学研究表明，FeS2 CL@WS2 NS电催化剂的塔菲尔斜率为每十倍54 mV，低于WS2 NS（每十倍102 mV）和IrO2/泡沫镍（每十倍77 mV）。此外，FeS2 CL@WS2 NS电催化剂用于OER的电荷传输电阻（2.3 Ω）小于WS2 NS。这些更快的动力学性质反过来解释了FeS2 CL@WS2 NS电催化剂对OER的高催化活性。稳定性测试后样品的XPS和HRTEM结果证实，耐久性测量后Fe2+和W4+被氧化。因此，我们认为FeS2 CL@WS2 NS电催化剂是一种有前途的高效、低成本和稳定的非贵金属基OER电催化剂候选材料。
