Li Yangyang, Yu Zhi Gen, Wang Ling, Weng Yakui, Tang Chi Sin, Yin Xinmao, Han Kun, Wu Haijun, Yu Xiaojiang, Wong Lai Mun, Wan Dongyang, Wang Xiao Renshaw, Chai Jianwei, Zhang Yong-Wei, Wang Shijie, Wang John, Wee Andrew T S, Breese Mark B H, Pennycook Stephen J, Venkatesan Thirumalai, Dong Shuai, Xue Jun Min, Chen Jingsheng
Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore.
Institute of High Performance Computing, Singapore, 138632, Singapore.
Nat Commun. 2019 Jul 17;10(1):3149. doi: 10.1038/s41467-019-11124-w.
Transition metal oxides exhibit strong structure-property correlations, which has been extensively investigated and utilized for achieving efficient oxygen electrocatalysts. However, high-performance oxide-based electrocatalysts for hydrogen evolution are quite limited, and the mechanism still remains elusive. Here we demonstrate the strong correlations between the electronic structure and hydrogen electrocatalytic activity within a single oxide system TiO. Taking advantage of the epitaxial stabilization, the polymorphism of TiO is extended by stabilizing bulk-absent polymorphs in the film-form. Electronic reconstructions are realized in the bulk-absent TiO polymorphs, which are further correlated to their electrocatalytic activity. We identify that smaller charge-transfer energy leads to a substantial enhancement in the electrocatalytic efficiency with stronger hybridization of Ti 3d and O 2p orbitals. Our study highlights the importance of the electronic structures on the hydrogen evolution activity of oxide electrocatalysts, and also provides a strategy to achieve efficient oxide-based hydrogen electrocatalysts by epitaxial stabilization of bulk-absent polymorphs.
过渡金属氧化物表现出强烈的结构-性能相关性，这一点已得到广泛研究并被用于制备高效的氧电催化剂。然而，用于析氢的高性能氧化物基电催化剂相当有限，其机理仍然难以捉摸。在此，我们展示了单一氧化物体系TiO中电子结构与析氢电催化活性之间的强相关性。利用外延稳定化，通过在薄膜形式中稳定体相中不存在的多晶型物，TiO的多态性得以扩展。在体相中不存在的TiO多晶型物中实现了电子重构，这进一步与其电催化活性相关。我们发现，较小的电荷转移能量会导致电催化效率显著提高，同时Ti 3d和O 2p轨道的杂化更强。我们的研究突出了电子结构对氧化物电催化剂析氢活性的重要性，同时也提供了一种通过外延稳定体相中不存在的多晶型物来制备高效氧化物基析氢电催化剂的策略。
