Electronic-reconstruction-enhanced hydrogen evolution catalysis in oxide polymorphs

• Main Authors: 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, Wee, Andrew T. S., Wang, Shijie, Wang, John, Breese, Mark B. H., Pennycook, Stephen J., Venkatesan, Thirumalai, Dong, Shuai, Xue, Jun Min, Chen, Jingsheng
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2019
• Subjects: Electrocatalysis; Catalyst Synthesis; Science::Physics
• Online Access: https://hdl.handle.net/10356/107505; http://hdl.handle.net/10220/49721
• Institution: Nanyang Technological University

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 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.