Relationships Between Crystal, Internal Microstructures, and Physicochemical Properties of Copper-Zinc-Iron Multinary...

Rational design and fabrication of high quality complex multicomponent spinel ferrite with specific microstructures and solar light harvestings toward CO₂ reduction and antibiotic degradation to future energetic and catalytic applications are highly desirable. In this study, novel copper-zinc-iron multinary spinel hierarchical nano-microspheres (MSHMs) with different internal structures (solid nano-microspheres, yolk-shell hollow nano-microspheres, and double-shelled hollow nano-microspheres) have been successfully developed by a facile self-templated solvothermal strategy. The morphology and structure, optical, as well as photoinduced redox reactions including interfacial charge carrier behaviors and the intrinsic relationship of structure-property between intrinsic nano-microstructures and physicochemical performance of copper-zinc-iron ferrite MSHMs composites were systematically investigated with the assistance of various on- and/or off- line physical-chemical means and deeply elucidated in terms of the research outcomes. It is demonstrated that the modification of the interior microstructures can be applied to tune the catalytic properties of multinary spinel by tailoring the temperature programming to fine control the two opposite forces of contraction (Fc) and adhesion (Fa). Among various internal microstructures, the obtained double-shelled copper-zinc-iron MSHMs exhibited the superior catalytic performance toward 8.8 and 38 μmol for H₂ and CO productions as well as 80.4% removal of sulfamethoxazole antibiotics. As evidenced from primary characterizations, for example, combined steady-state PL, ns-TAS, and Mössbauer and sequential investigations, the remarkable improvements in the catalytic activity can be primarily attributed to several crucial factors, for example, the more effective e^--h⁺ spatial separations and interfacial transfers, multiple internal light scattering, higher photonic energy harvesting and effective reactive oxygen species generation with long radical lifetimes. The current research provides new insights into the molecular design of novel copper-zinc-iron multinary spinels and the intrinsic relationship of structure-property between interior structures (e.g., different crystal texture, morphologies structures) and the physicochemical performance of the aforementioned multinary spinels.