Recently, single‐atom catalysts have aroused extensive attention in fields of clean energy and environmental protection due to their unique activity and efficient utilization of the active atoms. It is of great importance but still remains a great challenge to unveil the effect of single atoms on precise catalysis. Herein, it is reported that doping TiO₂ hollow microspheres (TiO₂‐HMSs) with single atomic Fe can boost the photoreactivity of TiO₂‐HMSs towards NO oxidation due to the synergistic effects of atomically dispersed Fe and bonded Ti atom which act as dual active sites. The atomically dispersed Fe atoms occupy the subsurface Ti vacancies, and the interaction between Ti 3d and Fe 3d orbitals result in the formation of FeTi bond. Single atomic Fe modulates the electronic structure of the bonded Ti atoms by electron transfer, which facilitates the adsorption and activation of NO and O₂ at Fe and bonded Ti sites, respectively. In addition, the introduction of single atomic Fe sharply suppresses the production of toxic NO₂ byproduct. The synergistic effects of the dual active sites then cause a drastic promotion in photocatalytic oxidation of NO.

中文翻译：

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Fe1 / TiO2空心微球：Fe和Ti双活性位促进NO的光催化氧化

近年来，单原子催化剂因其独特的活性和有效利用活性原子而在清洁能源和环境保护领域引起了广泛关注。揭示单个原子对精确催化的作用非常重要，但仍然是巨大的挑战。在此，据报道，由于原子分散的Fe和结合的Ti原子的双重作用，用单原子Fe掺杂TiO ₂中空微球（TiO ₂ -HMSs）可以提高TiO ₂ -HMSs对NO氧化的光反应性。活动站点。原子上分散的Fe原子占据了表面下的Ti空位，并且Ti 3d和Fe 3d轨道之间的相互作用导致形成Fe钛键。单原子铁通过电子转移调节键合的钛原子的电子结构，这分别促进了铁和键合的钛位置上NO和O ₂的吸附和活化。另外，单原子铁的引入大大抑制了有毒NO ₂副产物的产生。然后，双重活性位点的协同作用会大大促进NO的光催化氧化。