Li Junmin, Wu Geng, Huang Zixiang, Han Xiao, Wu Bei, Liu Peigen, Hu Haohui, Yu Ge, Hong Xun
Center of Advanced Nanocatalysis (CAN), Department of Applied Chemistry, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China.
National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China.
JACS Au. 2024 Mar 12;4(3):1243-1249. doi: 10.1021/jacsau.4c00085. eCollection 2024 Mar 25.
Integrating multiple functional components into vertically stacked heterostructures offers a prospective approach to manipulating the physicochemical properties of materials. The synthesis of vertically stacked heterogeneous noble metal oxides remains a challenge. Herein, we report a surface segregation approach to create vertically stacked amorphous Ir/Ru/Ir oxide nanosheets (NSs). Cross-sectional high-angle annular darkfield scanning transmission electron microscopy images demonstrate a three-layer heterostructure in the amorphous Ir/Ru/Ir oxide NSs, with IrO layers located on the upper and lower surfaces, and a layer of RuO sandwiched between the two IrO layers. The vertically stacked heterostructure is a result of the diffusion of Ir atoms from the amorphous IrRuO solid solution to the surface. The obtained A-Ir/Ru/Ir oxide NSs display an ultralow overpotential of 191 mV at 10 mA cm toward acid oxygen evolution reaction and demonstrate excellent performance in a proton exchange membrane water electrolyzer, which requires only 1.63 V to achieve 1 A cm at 60 °C, with virtually no activity decay observed after a 1300 h test.
将多个功能组件集成到垂直堆叠的异质结构中为操控材料的物理化学性质提供了一种前瞻性方法。垂直堆叠的异质贵金属氧化物的合成仍然是一个挑战。在此，我们报道一种表面偏析方法来制备垂直堆叠的非晶态 Ir/Ru/Ir 氧化物纳米片（NSs）。横截面高角度环形暗场扫描透射电子显微镜图像表明非晶态 Ir/Ru/Ir 氧化物 NSs 具有三层异质结构，IrO 层位于上下表面，一层 RuO 夹在两层 IrO 层之间。垂直堆叠的异质结构是 Ir 原子从非晶态 IrRuO 固溶体扩散到表面的结果。所获得的 A-Ir/Ru/Ir 氧化物 NSs 在 10 mA cm 下对酸性析氧反应显示出 191 mV 的超低过电位，并且在质子交换膜水电解槽中表现出优异性能，在 60°C 下达到 1 A cm 仅需 1.63 V，在 1300 h 测试后几乎没有观察到活性衰减。
