@article{Shang2026, 
author = {Huan Shang and Yue He and Qing Wang and Hongbao Jia and Jiale Wang and Hengcan Zhao and Xinwang Chen and Xinyu Deng and Ziyan Zhang and Shuwei Gu and Jue Wu and Jian Zhu and Guisheng Li and Hexing Li and Dieqing Zhang},
title = {Dual-active-site engineering via orbital modulation of Fe single atoms on defective TiO2 for enhanced photocatalytic NO removal},
year = {2026},
journal = {Nano Research},
volume = {19},
number = {6},
pages = {94908244},
keywords = {photocatalysts, O2 activation, NO removal, dual-active-site, orbital modulation},
url = {https://www.sciopen.com/article/10.26599/NR.2025.94908244},
doi = {10.26599/NR.2025.94908244},
abstract = {Nitrogen monoxide (NO), a critical precursor to particulate matter with an aerodynamic diameter ≤ 2.5 μm (PM2.5) and ozone formation, requires efficient abatement at atmospheric low concentrations (< 1 ppm), yet conventional photocatalysts struggle with deep NO purification due to inefficient trace O2/NO co-activation. Herein, we engineer Fe single atoms on defective TiO2 catalyst (FeSA/OV-TiO2, OV refers to oxygen vacancy) with orbital-modulated dual-active sites. Density functional theory calculations and in situ characterizations reveal that surface oxygen vacancies drive robust O2 activation to generate reactive oxygen species (ROS). Adjacent Fe single atoms enable targeted NO chemisorption via their d-orbital hybridization with antibonding π* orbital of NO. This synergy shifts the NO oxidation pathway from ·O2−-dominated Eley–Rideal (E–R) to dual-activated Langmuir–Hinshelwood (L–H) pathways, where pre-adsorbed NO directly reacts with ROS, forming thermodynamically stable bidentate nitrate. Crucially, FeSA/OV-TiO2 achieves 75% NO conversion efficiency with 98% nitrate selectivity under visible light irradiation, outperforming defective TiO2-OV by 1.4-fold while maintaining the good activity over five cycles without deactivation. The work establishes orbital-level dual-site engineering as a strategy for developing high-efficiency photocatalysts for air pollution remediation.}
}