Oriented generation of 1O2 from peroxymonosulfate via Co3O4 facet engineering

Abstract

In this study, we synthesized Co3O4 nanoparticles with distinct morphologies, including nanocube, nanotruncated octahedron, and nanopolyhedron with featured exposure of (001), (111), and (112) facets, respectively. The Co3O4-NC/CNTs-PMS (peroxymonosulfate) system demonstrated a significantly higher steady-state 1O2 concentration of 8.84×10⁻¹⁰ M with 99.5 % selectivity, marking a 462-fold increase compared to Co3O4-NP/CNTs-PMS. Density Functional Theory (DFT) calculations revealed that the (001) facet facilitates 1O2 production by lowering the energy barrier for the rate-determining step from *OH to *O. Furthermore, we introduced the sum of Hammett sigma-para constants (∑σp) as a predictive descriptor, capable of estimating degradation rates with 87 % accuracy. This study systematically elucidates the influence of Co3O4 crystal facets on 1O2 generation, providing valuable insights into the design of catalysts and optimization of PMS activation strategies for the efficient degradation of recalcitrant pollutants in complex water matrices.