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Updated: Apr 11, 2026

Exploring the Radical Nature of a Carbon Surface by Electron Paramagnetic Resonance and a Calibrated Gas Flow
Published on: April 24, 2014
Structure-dependent radical-nonradical transition in endogenous and exogenous Fe single-atom anchored biochar derived
Fangzhou Li1, Botu Xiong2, Ziren Wan3
1School of Resources and Environmental Engineering, Shanghai Polytechnic University, Shanghai 201209, China; School of Environment, Tsinghua University, Beijing 100084, China; State Key Laboratory of Regional Environment and Sustainability, Beijing 100084, China.
Abstract:
Exploring single-atom catalysts (SACs) with green synthesis via endogenous approach has attracted increasing attention for environmental remediation. Herein, endogenous Fe single-atom anchored biochar (FeN3O1-ZBC) and exogenous Fe single-atom anchored biochar (FeN4-BC) were synthesized using hyperaccumulators (Sedum alfredii) for peroxymonosulfate activation, enabling a systematic comparison of the mechanistic and energy efficiency differences. Radicals (•OH and SO4•-: 74.1%) predominantly contributed to the FeN4-BC/PMS system, and the energy efficiency exhibited a concentrated interquartile range (IQR) across different pollutants. In contrast, the electron transfer process (ETP, 82.6%) was the dominant mechanism in the FeN3O1-ZBC/PMS system, where spontaneous oxygen doping in the Fe coordination environment enhanced electron transfer capacity by modulating the surface potential and optimizing the energy level distribution of Fe 3d orbitals. FeN3O1-ZBC exhibited a broader IQR in energy efficiency compared to FeN4-BC, with significant selectivity for electron-rich pollutants and a minimum electric energy per order (EE/O) of just 0.64 kWh·m-3·order-1. This work deepens the understanding of structure-function relationships in single-atom catalysts and provides new insights into the formation mechanism and catalytic efficiency of endogenous single-atom catalysts derived from heavy metal-contaminated biomass.
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