Cao Dong, Shao Jie, Cui Yahui, Zhang Lipeng, Cheng Daojian
State Key Laboratory of Organic-Inorganic Composites and Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, P. R. China.
Small. 2023 Aug;19(33):e2301613. doi: 10.1002/smll.202301613. Epub 2023 Mar 26.
Fabricating heterogeneous interfaces is an effective approach to improve the intrinsic activity of noble-metal-free catalysts for water splitting. Herein, 3D copper-nickel selenide (CuNi@NiSe) nanodendrites with abundant heterointerfaces are constructed by a precise multi-step wet chemistry method. Notably, CuNi@NiSe only needs 293 and 41 mV at 10 mA cm for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), respectively. Moreover, the assembled CuNi@NiSe system just requires 2.2 V at 1000 mA cm in anion exchange membrane (AEM) electrolyzer, which is 2.0 times better than Pt/C//IrO . Mechanism studies reveal Cu defects on the Cu Se surface boost the electron transfer between Cu atoms and Se atoms of Ni Se via Cu Se/Ni Se interface, largely lowering the reaction barrier of rate-determining step for HER. Besides, the intrinsic activity of Ni atoms for in situ generated NiOOH is largely enhanced during OER because of the electron-modulating effect of Se atoms at Ni Se /NiOOH interface. The unique 3D structure also promotes the mass transfer during catalysis process. This work emphasizes the essential role of interfacial engineering for practical water splitting.
构建异质界面是提高无贵金属析水催化剂本征活性的有效方法。在此，通过精确的多步湿化学方法构建了具有丰富异质界面的三维铜镍硒化物（CuNi@NiSe）纳米枝晶。值得注意的是，CuNi@NiSe在10 mA cm下的析氧反应（OER）和析氢反应（HER）分别仅需293和41 mV。此外，组装的CuNi@NiSe体系在阴离子交换膜（AEM）电解槽中在1000 mA cm下仅需2.2 V，比Pt/C//IrO 好2.0倍。机理研究表明，CuSe表面的Cu缺陷通过CuSe/NiSe界面促进了Cu原子与NiSe的Se原子之间的电子转移，大大降低了HER速率决定步骤的反应势垒。此外，由于Se原子在NiSe /NiOOH界面的电子调制作用，在OER过程中，原位生成的NiOOH中Ni原子的本征活性大大增强。独特的三维结构也促进了催化过程中的传质。这项工作强调了界面工程在实际析水中的重要作用。
