1 College of Chemistry, Chemical Engineering and Materials Science, Key Laboratory of Molecular and Nano Probes (Ministry of Education), Shandong Normal University, Jinan, Shandong, 250014, P. R. China. xiejf@sdnu.edu.cn.
2 School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, Shandong, P. R. China.
In this work, a grain-boundary-engineered porous CuO/Co3O4 heterostructure was fabricated as a dynamic pre-catalyst, where tailored grain boundaries and nanopores facilitate pre-oxidation to activate high-valence species for robust oxygen evolution.