Tae See-Eun, Yen Zhihao, Kim Yejin, Zhang Mengyuan, Luo Wenyu, Yan Qingyu, Jang Hyeonseo, Han Byoung Gun, Lam Yeng Ming, Cho Deok-Yong
Department of Physics, Jeonbuk National University Jeonju 54896 Republic of Korea
Department of Materials Science and Engineering, Nanyang Technological University N4.1-1-28, Nanyang Avenue Singapore 639798 Singapore
Nanoscale Adv. 2025 Aug 16. doi: 10.1039/d5na00492f.
The chemical and atomic structures of Cu-, Ni-, or CuNi-embedded MXene (TiCT , T = O or OH) nanosheet catalysts are examined by using various characterization methods to demonstrate the chemical origin of their composition-dependent evolution. The results of combined X-ray spectroscopy studies and the electrochemical test reveal that Cu ions in (Cu or CuNi):MXene remain active having a +1 valence and form metallic Cu-Cu bonds to enhance the catalytic activity for nitrate reduction. By contrast, Ni ions in (Ni or CuNi):MXene tend to remain bound to O as in NiO staying inactive, and, furthermore, hinder the catalytic activity of Cu when co-doped on MXene. It is also demonstrated that chemistry of MXene itself varies by donating electrons from Ti to Cu to stabilize the active Cu ions. These findings support a combinational mechanism in which both the abundant metallic bonds and the cooperative chemical reconstruction that happened MXene-to-Cu charge transfer facilitate the single atom-aided functionalization of MXene catalysts.
通过使用各种表征方法研究了嵌入铜、镍或铜镍的MXene（TiCT ，T = O或OH）纳米片催化剂的化学和原子结构，以证明其成分依赖性演变的化学起源。结合X射线光谱研究和电化学测试的结果表明，（铜或铜镍）：MXene中的铜离子保持+1价的活性，并形成金属铜-铜键以增强硝酸盐还原的催化活性。相比之下，（镍或铜镍）：MXene中的镍离子倾向于像在NiO 中一样与氧结合而保持惰性，而且，当共掺杂在MXene上时会阻碍铜的催化活性。还证明了MXene本身的化学性质通过从钛向铜提供电子来稳定活性铜离子而发生变化。这些发现支持了一种组合机制，即丰富的金属键和发生在MXene到铜电荷转移过程中的协同化学重构促进了MXene催化剂的单原子辅助功能化。
