Self‐Reconstruction of Single‐Atom‐Thick A Layers in Nanolaminated MAX Phases for Enhanced Oxygen Evolution
Chun Hu, Huilong Dong, Youbing Li, Sapna Sinha, Changda Wang, Wenjie Xu, Li Song, Kazu Suenaga, Hongbo Geng, Jiacheng Wang, Qing Huang, Yuan‐Zhi Tan, Xiaoqing Huang
Abstract
Abstract M n+1 AX n (MAX) phases are a family of nanolaminated ternary carbide/nitride, which are generally investigated as high‐safety structural materials, but their direct applications on electrocatalysis is still far from reality. Here, it is shown that by taking the advantages of self‐reconstruction, a unique class of MAX phases of V 2 (Sn, A)C (A = Ni, Co, Fe) can be adopted as efficient catalysts for oxygen evolution reaction (OER). The specific single‐atomic‐thick (Sn, A) layers within V–C networks in V 2 (Sn, A)C are highly flexible to react with electrolyte. As a result, the V 2 (Sn, Ni)C (VSNC) can maintain bulk crystalline structure, and merely encounter surface reconstruction to generate Ni‐based oxyhydroxide accompanying with the self‐doping of V and Sn elements under alkaline OER condition. The surface‐reconstructed VSNC exhibits significantly enhanced OER performance to that of reconstructed Ni nanopowder and V 2 SnC. Density functional theory simulations indicate that the doping of Sn/V into γ‐NiOOH leads to the change of reaction pathway of alkaline OER, while the introduction of V can reduce the reaction barrier to facilitate the OER process. This study exhibits a new functionality of a unique MAX phase toward OER, which puts forward the potential applications of MAX phase materials in electrocatalysis and beyond.