@article{Guo2025, 
author = {Jingjing Guo and Ying Zhang and Jun Wang and Jiankang Zheng and Shi Zhang and Ruilong Li and Xiao Han and Geng Wu and Xiao-Cheng Liu and Yang Mu and Xun Hong},
title = {Phase-engineered coordinatively unsaturated metal sites in spinel oxides for robust Fenton-like catalysis},
year = {2025},
journal = {Nano Research},
volume = {18},
number = {6},
pages = {94907476},
keywords = {spinel oxide, amorphous, phase engineering, coordinatively unsaturated metal sites, Fenton-like catalysis},
url = {https://www.sciopen.com/article/10.26599/NR.2025.94907476},
doi = {10.26599/NR.2025.94907476},
abstract = {Coordinatively unsaturated metal sites (CUS) located at tetrahedral (Td) in spinel structure are highly effective for activating peroxymonosulfate (PMS) in Fenton-like catalysis. However, the conventional Td−octahedral (Oh) connectivity in spinel structures restricts internal electron transfer, limiting the regeneration of low-valent metals and creating a trade-off between catalytic activity and long-term stability. Herein, we address this challenge by engineering a novel Td−Td connectivity in amorphous CoFeOx nanosheets (a-CoFeOx NSs). Soft X-ray absorption spectroscopy (sXAS) measurements reveal that in a-CoFeOx nanosheets, the ligand field symmetry around Co atoms is dominated by a Td coordination, in contrast to the Oh coordination in the crystalline state, which introduces Td−Td connection. Density functional theory (DFT) calculations confirm that the Td−Td connection in a-CoFeOx structure significantly strengthens electron transfer to activate PMS, which exhibited a first-order kinetic constant (kobs) of 0.27 min−1 for sulfamethoxazole (SMX) removal with high stability. This study reveals that the phase-engineered CUS can further enhance catalytic activity and provides a simple and scalable strategy for optimizing spinel-type catalysts.}
}