Uniformed core-shell FeSe2+x@C nanocube superlattices for Fenton-like reaction: Coordinative roles of cation and anion

Simultaneously adjusting the coordination environment of Fenton-like catalysts and engineering their architectures is a viable strategy to promote catalytic reaction. Herein, two-dimensional (2D) porous core-shell FeSe2+x @C nanocube superlattices (NCSLs) with unsaturated selenium are for the first time prepared via onestep selenization of Fe3O4@C NCSLs and tested for peroxymonosulfate (PMS)-based Fenton-like reaction. The 2D porous superlattice structure can preferably expand Fe sites exposure and accelerate the large-scale transport and utilization of nanocrystals. The unsaturated selenium can optimize the electronic state of cationic Fe, not only promoting the Fe3+/Fe2+ cycle, regulating PMS adsorption, and improving the charge density, but also accelerating interfacial electron transport of the catalyst to lower the energy barrier of PMS decomposition to yield SO4 & BULL; . This work demonstrates a new application of nanocrystal superlattices and provides more insights to active components of catalyst design for enhancing catalytic activity via structural control and coordination engineering in various application scenarios.

Automated summary

Modifying the coordination environment and engineering the architecture of Fenton-like catalysts can effectively enhance catalytic reactions. In this study, two-dimensional (2D) porous core-shell FeSe2+x@C nanocube superlattices (NCSLs) with unsaturated selenium were synthesized for the first time, and were tested for peroxymonosulfate (PMS)-based Fenton-like reaction. The 2D porous superlattice structure expanded the exposure of Fe sites and facilitated the transport and utilization of nanocrystals. The unsaturated selenium optimized the electronic state of cationic Fe, promoting the Fe3+/Fe2+ cycle, regulating PMS adsorption, improving the charge density, and accelerating interfacial electron transport, thus reducing the energy barrier for PMS decomposition.