Authors: Yangyang Li, Zhi Gen Yu, Ling Wang, Yakui Weng, Chi Sin Tang, Xinmao Yin, Kun Han, Haijun Wu, Xiaojiang Yu, Lai Mun Wong, Dongyang Wan, Xiao Renshaw Wang, Jianwei Chai, Yong-Wei Zhang, Shijie Wang, John Wang, Andrew T. S. Wee, Mark B. H. Breese, Stephen J. Pennycook, Thirumalai Venkatesan, Shuai Dong, Jun Min Xue, Jingsheng Chen
Published: 2019-07-17
DOI: 10.1038/s41467-019-11124-w
Source: Full article
AbstractTransition 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 Ti2O3. Taking advantage of the epitaxial stabilization, the polymorphism of Ti2O3 is extended by stabilizing bulk-absent polymorphs in the film-form. Electronic reconstructions are realized in the bulk-absent Ti2O3 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.