Decoupling the impacts of engineering defects and band gap alignment mechanism on the catalytic performance of holey 2D CeO2-x-based heterojunctions
This is the peer reviewed version of the following article: Zheng, X., Mofarah, S. S., Cazorla, C., Daiyan, R., Esmailpour, A. A., Scott, J., Yao, Y., Lim, S., Wong, V., Chen, E. Y., Arandiyan, H., Koshy, P., Sorrell, C. C., Decoupling the Impacts of Engineering Defects and Band Gap Alignment Mechanism on the Catalytic Performance of Holey 2D CeO2−x-Based Heterojunctions. Adv. Funct. Mater. 2021, 31, 2103171, which has been published in final form at https://doi.org/10.1002/adfm.202103171. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley's version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited. ; Critical catalysis studies often lack elucidation of the mechanistic role of defect equilibria in solid solubility and charge compensation. This approach is applied to interpret the physicochemical properties and catalytic performance of a free-standing 2D–3D CeO2-x scaffold, which is comprised of holey 2D nanosheets, and its heterojunctions with MoO3-x and RuO2. The band gap alignment and structural defects are engineered using density functional theory (DFT) simulations and atomic characterization. Further, the heterojunctions are used in hydrogen evolution reaction (HER) and catalytic ozonation applications, and the impacts of the metal oxide heteroatoms are analyzed. A key outcome is that the principal regulator of the ozonation performance is not oxygen vacancies but the concentration of Ce3+ and Ce vacancies. Cation vacancy defects are measured to be as high as 8.1 at% for ...