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Singlet oxygen (1O 2) is a highly effective reactive species in selectively oxidizing organic pollutants. However, it is still challenging to rationally design robust catalysts for the selective generation of 1O 2. Herein, the coordination and engineering architecture of the foam board-like CoSe 2 alloy were facilely constructed through a green solvent-free method and displayed almost 100% 1O 2 production selectivity. The CoSe 2 alloy showed excellent catalytic ability for the efficient and fast removal of organic pollutants via peroxymonosulfate (PMS) activation compared with previously reported cobalt-based catalysts. The CoSe 2 /PMS system exhibited strong resistance for a broad pH range (3.0–11.0) and various coexisting inorganic ions owing to the advantage of the strong bonding of Co-Se in CoSe 2 alloy. Mechanism studies revealed that 1O 2 was the only reactive oxygen species in the CoSe 2 /PMS system. Theoretical calculations demonstrated that Co was the dominant adsorption site for PMS in CoSe 2 , and the production pathway of 1O 2 was PMS* → *OH → *O → 1O 2. In addition, it was proved that *OH and *O served as the rate-determining steps for the formation of 1O 2 by PMS activation on CoSe 2 alloy. These findings provide a rational strategy for preparing a series of low-cost transition metal-based alloy catalysts for PMS activation to achieve high-efficiency 1O 2 production in the elimination of organic pollutants. [Display omitted] • The foam board-like CoSe 2 alloy was facilely fabricated through a green solvent-free method. • CoSe 2 exhibited excellent catalytic performance for PMS activation. • The CoSe 2 /PMS system achieved almost 100% 1O 2 production selectivity. • *OH and *O served as the rate-determining steps for the formation of 1O 2. • 100% sulfadiazine was stably removed via a continuous flow reactor in 6 h. [ABSTRACT FROM AUTHOR]

• Fine CoFe 2 O 4 was in-situ fabricated on biomass waste-derived porous carbon framework. • CoFe 2 O 4 /C exhibited large surface area of 733.1 m2/g and presented rich oxygen vacancies. • CoFe 2 O 4 /C catalysts can directly activate PMS to efficiently remove four typical quinolones. • ∼94.8% CIP, ∼96.8% OFL, ∼100% LEV, ∼86% NOR can be efficiently degraded in 12 min. • DFT calculations elucidated the possible adsorption behavior and activation mechanism. Rational design of the low-cost, highly efficient and easily recyclable catalyst to directly activate peroxymonosulfate (PMS) is crucial for the efficient removal of organic pollutants in the sewage treatment. Herein, hyperdispersed CoFe 2 O 4 spinel nanoparticles were successfully in-situ fabricated on biomass-derived 3D porous carbon framework (C) by the facile one-step solvothermal method (CoFe 2 O 4 /C). These as-prepared CoFe 2 O 4 /C exhibit superior performance in the Fenton-like removal of four quinolones by the combination of experimental work and theoretical calculation. Experimental results prove that CoFe 2 O 4 /C catalyst can directly activate PMS to efficiently remove four types of quinolones in 12 min without the external energy consumption. The characterization results show that hyperdispersed CoFe 2 O 4 (18.0 ± 5.0 nm) nanoparticles are uniformly anchored on the matrix of C, exhibit a large specific surface area of 733.1 m2/g, and present rich oxygen vacancies (O vs), thus exposing more reactive sites and generating more reactive oxygen species (ROS). In CoFe 2 O 4 /C + PMS system, ∼97.5% of ciprofloxacin (CIP) is removed within 12 min, which is far superior to other candidates previously reported. Other quinolones (e.g., ∼96.8% of ofloxacin (OFL), ∼100% of levofloxacin (LEV), and ∼86.4% of norfloxacin (NOR)) can also be efficiently degraded under the same conditions. Based on quenching experiments, electron spin resonance spectroscopy (ESR), and density functional theory (DFT) calculations, these superior activities are mainly due to the free radical (SO 4 ·-, ·OH, and ·O 2 –) and non-free radical (1O 2), whereas SO 4 ·- and ·OH are the major reactive oxygen species. In addition, these CoFe 2 O 4 /C catalysts remain stable even after five cycles. Subsequently, degradation pathways are rationally proposed. This work provides a feasible and universal strategy for the direct activation of PMS in wastewater treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • Rational design and synthetic strategies of multifarious SMOs are summarized. • Intrinsic relationship between SMO's structure and catalytic properties is analyzed. • The photocatalytic mechanism of SMOs for antibiotics degradation is revealed. • Challenges and prospects of SMOs for antibiotics degradation are highlighted. Due to the permanent harm to human health and ecosystem balance, antibiotic pollution in water has become an important direction of current environmental governance. Spherical metal oxides (SMOs) have been frequently utilized as effective heterogeneous photocatalysts for the efficient degradation of antibiotics due to their unique properties (e.g., strong light absorption ability, high separation efficiency of photo-generated electron-hole pairs, and good catalytic activity). This review will firstly focus on summarizing the rational design and synthesis of SMOs with various tuned microstructures such as hollow, porous shell, yolk shell, core shell, and nanoflowers. These structures can expose more active sites, achieve a higher utilization rate of light, enhance the mass transfer efficiency and improve the effective diffusion of reactive oxygen species (ROS). Secondly, this review will mainly analyze the intrinsic relationship between the structure of SMOs and their photocatalytic property, the ability to generate ROS, and the degradation pathway for antibiotics. Moreover, the photocatalytic mechanisms and recent progress of different SMO catalysts for degrading typical antibiotics are compared in detail. Finally, challenges and prospects of future direction in the development of SMOs for antibiotic degradation are reviewed. It is expected to provide a rational design of SMO catalysts for efficient photocatalytic degradation of environmental pollutants. [ABSTRACT FROM AUTHOR]

How to efficiently and fast remove the serious perniciousness of the residual antibiotics in water environment is crucial for protecting ecosystem. Herein, we reported the Fenton-like system based on layered double hydroxides (LDHs) nanosheets for direct peroxymonosulfate (PMS) activation efficient for fast removing the typical five fluoroquinolones antibiotics ciprofloxacin (CIP), norfloxacin (NOR), levofloxacin (LEV), enrofloxacin (ENR) and ofloxacin (OFL). A series of CoFe-LDHs nanosheets was one-step fabricated by integrating coprecipitation and in-situ exfoliation method. The as-obtained CoFe-LDHs nanosheets catalysts exhibit thin nanosheets (~3 nm) with high redox properties, abundant oxygen vacancies, appreciable adsorption capacity, remarkable catalytic performance and favorable stability. The variable valent state, cheap, easy-to-obtain and low-toxic Co and Fe elements were used to construct stable LDHs for efficient activation of PMS to degrade quinolone antibiotics. Among them, Co 1 Fe 1 -LDHs nanosheets exhibited the best CIP degradation efficiency of 86.9% within 12 min, which is superior to most of previous candidates. The impacts of different reaction parameters, catalyst stability, main reactive oxygen species, the main CIP degradation mechanism and rational degradation pathways were systematically studied. This work offers a feasible strategy to tune the performance of LDHs-based materials in Fenton-like system degradation of antibiotics. [Display omitted] • A series of CoFe-LDHs nanosheets were used to activate PMS to degrade quinolones. • The structure-activity relationship of CoFe-LDHs was studied. • The Co 1 Fe 1 -LDHs/PMS/CIP system could degrade 86.9% CIP within 12 min. • Degradation mechanism and pathway of ciprofloxacin was proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] • SNC honeycomb carbon was prepared via a facile impregnation-microwave method. • N and S co-implanted carbon created a synergistic effect for water remediation. • Positively charged carbon sites in SNC favor providing more active sites. • The exposed active sites (pyrrolic N and thiophene S) favor the production of O 2 −. • SNC with strong hydrophilicity and conductivity facilitates Photo-PMS degradation. Reactive oxygen species (ROS) generated via peroxymonosulfate (PMS) activation is crucial for degrading toxic pollutants. Herein, the co-implantation of S and N in carbon (SNC) was facilely constructed as Fenton-like photocatalysts for water remediation. Experimental and theoretical prediction disclosed that the electron cloud density around the C atom weakens the adjacent N-O as well as S-O bond due to the fracture of the surface N/S-O bond, facilitating electron transfer and subsequently the activation of surface lattice oxygen. The electronic effect of SNC catalysts with different S and N doping amounts was later regulated, and the rational reaction mechanism of the 2SNC + PMS + light (L) system was proposed. The obtained 2SNC exposed more exposed active sites (e.g., thiophene S and pyrrolic N) to effectively activate PMS with high performance by generating dominant active species superoxide radicals (O 2 −) in water remediation. The activity surpasses the results reported previously. A degradation rate of Aspirin (Asp) was up to 95.1% and the mineralization rate of 70.6% was reached in 40 min. Besides, these fabricated 2SNC catalysts were also suitable for the degradation of other phenolic pollutants (phenol (P), bisphenol A (BPA), 2,6-dimethylphenol (DMP), and p-chlorophenol (CP)) with the removal rate of over 70% in 40 min. Furthermore, the catalyst maintained satisfactory efficiency in actual water samples. This study provides a new guideline for developing S and N co-implanted carbon for water remediation. [ABSTRACT FROM AUTHOR]