Fe-based single-atom catalysis for oxidizing contaminants of emerging concern by activating peroxides

Facile Synthesis of Atomic Fe‐N‐C Materials and Dual Roles Investigation of Fe‐N4 Sites in Fenton‐Like Reactions

“…Usually, in a system dominated by high‐valent Fe, the oxidation process will be ended with PMSO converted into PMSO 2 , and further degradation will not happen. [ 50–52 ] Therefore, we speculate that this process is not dominated by high‐valence Fe.…”

Synthetic strategies for MOF-based single-atom catalysts for photo- and electro-catalytic CO2 reduction

“…MOFs have poor stability under relatively harsh chemical conditions and poor electrical conductivity, which limits its application in electrocatalysis. However, through a high-temperature pyrolysis under the protection of inert gases, the organic components are carbonized to form carbon-based materials doped with heteroatoms such as nitrogen and oxygen (Gao et al, 2021;Zhou et al, 2021b). The graphite-like structure significantly improves the electrical conductivity of the materials, whereas the retention of spatial topology in the pyrolysis process makes the MOF-derived material still has good mass transfer performance (Li et al, 2020b).…”

Outlook on Single Atom Catalysts for Persulfate-Based Advanced Oxidation

“…Carbon-based materials are commonly used as substrates to host SACs, since they provide ample anchoring sites ( e.g ., surface defects, vacancies) and their surface properties can be tuned by functionalization, heteroatom doping, coating, and/or hierarchical structuring to improve binding. The relatively high electrical conductivity of saturated carbon materials can also facilitate the electron transfer through the catalytic site, which is beneficial for persulfate activation by mediated electron transfer (discussed below). , Examples include graphitic carbon, ,, reduced graphene oxide (rGO), carbon nitride (C 3 N 4 ), ,,, carbon nanotubes (CNTs), MXene, metal organic frameworks (MOFs) such as zeolitic imidazolate framework (ZIF), ,, covalent organic frameworks (COFs), and biochar. , The electronic properties ( e.g ., conductivity), surface functional groups, and physical structures ( e.g ., from one to three dimensions) of these carbon supports have been shown to affect SAC-persulfate interactions. ,,, Besides carbon-based supports, semiconductors such as TiO 2 and MoS 2 have also been employed for SAC-enhanced photocatalytic activation of PMS. Other materials such as metal oxides ( e.g ., MgO, FeO x , ZnO, WO 3 , CuO, Co 3 O 4 , Al 2 O 3 , CeO 2 ) and metal nanoparticles have been widely used to support SACs in various application fields but not yet for the SAC-persulfate system.…”

“…High-valent metal-oxo species (M (n+2)+ O), including Mn 5+ , Ru 5+ , Co 4+ , and Fe 4+ , − have been reported as the main contributors in some dissolved metal ion or metal oxide/nanoparticle systems. Recently, the same species have also been proposed as the main contributors for Fe SACs using both experiments and DFT calculations (Figure b). ,,− To identify the role of M (n+2)+ O, sulfoxides such as methyl phenyl sulfoxide (PMSO) can be used. PMSO can be selectively oxidized to sulfones ( e.g ., methyl phenyl sulfone, PMSO 2 ) by M (n+2)+ O .…”

“…The relatively high electrical conductivity of saturated carbon materials can also facilitate the electron transfer through the catalytic site, which is beneficial for persulfate activation by mediated electron transfer (discussed below). 66,67 Examples include graphitic carbon, 56,57,68 reduced graphene oxide (rGO), 61 carbon nitride (C 3 N 4 ), 52,64,69,70 carbon nanotubes (CNTs), 59 MXene, 71 metal organic frameworks (MOFs) such as zeolitic imidazolate framework (ZIF), 60,72,73 covalent organic frameworks (COFs), 74 and biochar. 34,62 The electronic properties (e.g., conductivity), surface functional groups, and physical structures (e.g., from one to three dimensions) of these carbon supports have been shown to affect SAC-persulfate interactions.…”