Transition Metal and Metal–N_x Codoped MOF‐Derived Fenton‐Like Catalysts: A Comparative Study on Single Atoms and Nanoparticles

Abstract

critical study topic in building structurereactivity correlations in broad catalytic research fields. [1-2] Especially, single-atom catalysts have emerged as a new research frontier in both energy and environmental sciences, featuring with atomically dispersed active sites and characteristic electronic properties. [3-11] On the other hand, water contaminations caused by toxic benzene-derived compounds, such as endocrine disruptors from the plastics industry, dyestuff pollution, and antibiotic used in the cultivation industry, have led to an enormous threat to the environment and human health. [12-16] In recent years, the peroxymonosulfate (PMS)-based Fenton-like catalytic oxidation process has been regarded as a clean approach to generating reactive oxygen species (ROS), which presents a promising potential to overcome the ever-growing pollutants in water systems resulted from the toxic benzene-derived compounds. [17-21] However, it is very hard to activate PMS to generate sufficient radicals to degrade water pollutants efficiently, which thus hinders the practical applications of PMS in the Fenton-like oxidation reactions. [22-24] To deal with these issues, abundant transition metal-based catalysts have been studied as for PMS-based Fenton-like oxidation To deal with the ever-growing toxic benzene-derived compounds in the water system, extensive efforts have been dedicated for catalytic degradation of pollutants. However, the activities and efficiencies of the transition metal-based nanoparticles or single-atom sites are still ambiguous in Fenton-like reactions. Herein, to compare the Fenton-like catalytic efficiencies of the nanoparticles and single atoms, the free-standing nanofibrous catalyst comprising Co nanocrystals and CoN x codoped carbon nanotubes (CNTs) or bare CoN x doped CNTs is fabricated. It is noteworthy that all these nanofibrous catalysts exhibit efficient activities, mesoporous structures, and conductive carbon networks, which allow a feasible validation of the catalytic effects. Benefiting from the maximized atomic utilization, the atomic CoN x centers exhibit much higher reaction kinetic constant (κ = 0.157 min −1) and mass activity toward the degradation of bisphenol A, far exceeding the Co nanocrystals (κ = 0.082 min −1). However, for the volume activities, the single-atom catalyst does not show apparent advantages compared to the nanocrystal-based catalyst. Overall, this work not only provides a viable pathway for comparing Fenton-like catalytic effects of transition metal-based nanoparticles or single atoms but also opens up a new avenue for developing prominent catalysts for organic pollutants' degradation. The ORCID identification number(s) for the author(s) of this article can be found under

Pd‐Single‐Atom Coordinated Biocatalysts for Chem‐/Sono‐/Photo‐Trimodal Tumor Therapies

“…[25,26] Recently, many types of ROS catalytic nanoagents have been found to show efficient catalytic activity for the CDT process, like noble metal Pd nanomaterials, metal oxides, and metalorganic frameworks. [20,[27][28][29][30][31][32] At present, the semiconductor materials (e.g., TiO 2 ) and conjugated organic structure (e.g., porphyrin) are the main materials that can be utilized to integrate CDT, SDT, and PDT in one nanoplatform. However, the CDT efficiency of TiO 2 -based semiconductor materials is relatively low.…”

Activity Trends and Mechanisms in Peroxymonosulfate‐Assisted Catalytic Production of Singlet Oxygen over Atomic Metal‐N‐C Catalysts

“…[34] Besides,n o peaks of metal phases can be observed, which is consistent with SEM and TEM results.Asrevealed by Raman spectroscopy (Figure S6 and Table S1), the intensity ratios of Dband to Gband (I D /I G )for the M-SACs and N-C are similar, which indicates that these catalysts have as imilar degree of structural defects. [35,36] Additionally,t he Brunner-Emmet-Te ller (BET) surface area and total pore volume of M-SACs and N-C measured by nitrogen sorption isotherms are all around 800 m 2 g À1 and 2cm 3 g À1 ,r espectively,w hich further identify the similarity on material structural and physicochemical properties (Figure 1h and Figure S7,S8, Table S2). [37,38] Thedetailed atomic structure and quantitative elemental analysis in M-SACs were characterized by X-ray photoelectron spectroscopy (XPS).…”

ROS‐Catalytic Transition‐Metal‐Based Enzymatic Nanoagents for Tumor and Bacterial Eradication

“…[129][130][131][132] The versatility of metal nodes and the connections in all possible directions endow MOFs with structural diversity and extensive physical and chemical properties. [131,133,134] With the development of synthetic methods and surface modification engineering, three efficient synthetic strategies (rapid nucleation, nanoreactor confinement, and coordination modulation) and two approaches for surface functionalization of MOF (covalent external surface and coordinative external surface) were used for designing MOF. [135] Plenty of MOFs with excellent enzyme-mimic activities has been applied in biomedicine.…”