School of Materials Science and Engineering, Taizhou University, 318000, Zhejiang, China.
Key Laboratory of Optical Field Manipulation of Zhejiang Province, and Key Laboratory of ATMMT Ministry of Education, Department of Physics, Zhejiang Sci-Tech University, 310000, Zhejiang, China.
Nanoscale. 2023 Feb 16;15(7):3550-3559. doi: 10.1039/d2nr07066a.
Efficient and low-cost transition metal single-atom catalysts (TMSACs) for hydrogen evolution reaction (HER) have been recognized as research hotspots recently with advances in delivering good catalytic activity without noble metals. However, the high-cost complex preparation of TMSACs and insufficient stability limited their practical applications. Herein, a simple top-down pyrolysis approach to obtain P-modified Co SACs loaded on the crosslinked defect-rich carbon nanosheets was introduced for alkaline hydrogen evolution, where Co atoms are locally confined before pyrolysis to prevent aggregation. Thereby, the abundant defects and the unsaturated coordination formed during the pyrolysis significantly improved the stability of the monatomic structure and reduced the reaction barrier. Furthermore, the synergy between cobalt atoms and phosphorus atoms was established to optimize the decomposition process of water molecules, which delivers the key to promoting the slow reaction kinetics of alkaline HER. As the result, the cobalt SAC exhibited excellent catalytic activity and stability for alkaline HER, with overpotentials of 70 mV and 192 mV at current densities of -10 mA cm and -100 mA cm, respectively.
高效且低成本的过渡金属单原子催化剂（TMSACs）在不使用贵金属的情况下，能够提供良好的催化活性，因此最近被认为是研究热点。然而，TMSACs 成本高且制备复杂，稳定性不足，限制了其实际应用。本文介绍了一种简单的自上而下的热解方法，用于制备负载在交联富缺陷碳纳米片上的 P 修饰 Co SACs，用于碱性析氢反应，其中 Co 原子在热解前被局部限制以防止聚集。因此，热解过程中形成的丰富缺陷和不饱和配位显著提高了单原子结构的稳定性，降低了反应势垒。此外，钴原子和磷原子之间的协同作用优化了水分子的分解过程，这为促进碱性 HER 缓慢反应动力学提供了关键。结果表明，钴 SAC 对碱性 HER 具有优异的催化活性和稳定性，在电流密度为-10 mA cm 和-100 mA cm 时，过电势分别为 70 mV 和 192 mV。
