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S-doped NiFe-based particles were prepared by a solvothermal method and used to degrade methylene blue (MB) aqueous solutions with visible light in a heterogeneous Fenton reaction. The obtained solid samples were characterized by XRD, SEM, TEM, and XPS. It was found that 0.2 g L -1 NiFe 2 S 4 can degrade 99.8% MB solution within 6 min in the presence of 5 mM H 2 O 2 and natural pH. The recycle experiments results indicate that the NiFe 2 S 4 catalyst possessed better stability than NiFe 2 O 4 . Furthermore, NiFe 2 S 4 particles can be easily separated from contaminant solution by using a magnet due to their excellent ferromagnetism. COD analysis experiments indicated that the COD removal rate of NiFe 2 S 4 is 73.1% in 30 min. A possible mechanism was proposed, and the degradation products were measured by LC-MS., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

A series of hydrogels were successfully prepared with low grade palygorskite and hydroxypropyl methyl cellulose as raw materials by free radical graft copolymerization method. The morphology, functional groups, crystalline phases and thermal stability of the hydrogels were characterized by SEM, FT‐IR, XRD and TG, respectively. The adsorption properties of hydrogels were tested. The water absorption rate of hydrogel with Jiangsu Xu Yu palygorskite (PGSH), Gansu Linze white grey palygorskite (WPGSH) and Gansu Linze red palygorskite (RPGSH) as raw materials was 1332 g/g, 1204 g/g and 1146 g/g, respectively. The three hydrogels showed excellent adsorption capacity for 100 mg/L methylene blue solution at room temperature, and the maximum adsorption capacities of PGSH, WPGSH and RPGSH were 236.44 mg/g, 227.72 mg/g and 223.01 mg/g, respectively. The adsorption kinetics of methylene blue over hydrogels was a pseudo two stage kinetic equation. [ABSTRACT FROM AUTHOR]

• Heteroatom (P, B, or S) incorporated amorphous NiFe-based nanocubes were synthesized. • Amorphous Ni–Fe–O–S nanocubes exhibited excellent degradation effect. • A possible mechanism for the degradation of MB had been presumed. • A possible degradation pathway is proposed. Ni 3 [Fe(CN) 6 ] 2 •10H 2 O were successfully synthesized by co-precipitation and heteroatom (P, B or S) incorporated amorphous NiFe-based nanocubes (Ni–Fe–O–M (M = P, B or S)) were successfully synthesized via one-step calcination of Ni 3 [Fe(CN) 6 ] 2 •10H 2 O and heteroatom containing molecules. The structure, morphology and optical properties of Ni–Fe–O–M (M = P, B or S) were well characterized by XRD, SEM, XPS and UV-vis diffuse reflectance spectra. The S incorporated NiFe-based nanocubes (Ni–Fe–O–S) are better in degrading MB than other NiFe-based nanocubes. The degradation efficiency of Ni–Fe–O–S was 98.9% within 10 min in the presence of 60 mg/L H 2 C 2 O 4 and 5 mM H 2 O 2 under visible light irradiation. The COD and TOC removal efficiencies were 69.6% and 51.1%, respectively. The degradation rates of 5 cycles in 10 min are 98.9%, 96.2%, 95.8%, 92.3% and 88.3%, respectively. In the MB degradation, hydroxyl radical is proved to be the main active free radical. C 8 H 11 N 2 O 3 S− 12 , NO 4 S−, C 6 H 6 O 3 S, C 6 H 5 NO 3 , C 8 H 12 N 2 , C 6 H 9 O 2 −, C 3 H 6 O 4 , C 3 H 4 O 4 and C 6 H 10 O are detected from the reaction solution by LS-MS and a possible pathway was accordingly proposed to elucidate the mechanism of MB degradation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Co-catalytic effect of 1 T-MoS 2 greatly enhances the efficiency of photo-Fenton degradation. • The degradation efficiency of MB and RhB both reached 99.8% in 18 min. • The ·OH and visible light have synergistic in the photo-Fenton degradation system. • Density functional theory (DFT) was used to simulate the adsorption energy of H 2 O 2. Right here, flower-like FeMoO 4 @1T-MoS 2 composites were prepared by modifying FeMoO 4 microspheres with two-dimensional lamellar 1T-MoS 2 as co-catalyst, which was used for photo-Fenton catalysis degradation of binary dyes mixed with methylene blue (MB) and rhodamine B (RhB). Then various parameters affecting the generation of ·OH in the system were investigated. Systematic research shows that the degradation efficiency of MB and RhB can reach 99.8% in 18 min when the Mo/Fe molar ratio of the composite is 1:1. Furthermore, these experiments data were fitted by pseudo-first order kinetics model and pseudo-second order kinetics model. Subsequently the density functional theory (DFT) simulation results showed that FeMoO 4 exhibited excellent adsorption for H 2 O 2 , and the introduction of 1T-MoS 2 played a certain role in the adsorption and activation of H 2 O 2. Finally, the degradation pathways of MB and RhB were proposed to determine intermediates during photo-Fenton process by LC-MS and the reaction mechanism was detailed investigated by quenching experiment of active free radicals. FeMoO 4 @1T-MoS 2 has also excellent stability and highlights the potential and prospect of the composite for dye wastewater treatment. [ABSTRACT FROM AUTHOR]

A diatomite coated mesh showing switchable wettability has been successfully fabricated via a spray-coating process. The switchable mesh allows separating various oil-water mixtures in one single device. The diatomite coated mesh operates in water-removing mode to permeate water in typical light oil-water mixtures. Moreover, the mesh can rapidly switch to oil-removing mode to permeate heavy oil in the heavy oil-water mixtures. Reversible transition between water-removing and oil-removing mode can be realized simply by prewetting the coated mesh with water and corresponding heavy oils alternately. In addition, the switchable mesh showed high separation efficiencies above 99.2% for a series of light or heavy oil-water mixtures. Furthermore, the as-prepared coated mesh can separate oils from harsh conditions, such as strong acidic, alkaline, hyperhaline solutions and hot water. Besides, we demonstrated the methyl blue adsorption performance with the diatomite at room temperature, showing excellent adsorption capacity for water remediation. [ABSTRACT FROM AUTHOR]

In this work, micro-spherical β-NiOOH/FeMoO 4 with multiple active sites was prepared by one-step solvothermal method and its performance in the photo-Fenton system was investigated. The results indicate that highest degradation efficiency of methylene blue (MB) was obtained when the molar ratio of nickel to iron was 1:2.5. In addition, composites were assessed for its degradation performance for MB by adjusting the concentration of H 2 O 2 , pH and catalyst dosage. The pseudo-first-order kinetic rate constant of MB degradation in β-NiOOH/FeMoO 4 catalyzed photo-Fenton system was 0.234 min−1 about 5 folds that of pristine FeMoO 4 micro-sphere. The degradation mechanism of MB was deduced by active species quenching experiments and technology of coumarin fluorescent probe. And its degradation pathway was proposed by LC-MS identifying reaction intermediates produced during photo-Fenton catalysis. Recycling tests have confirmed excellent stability of β-NiOOH/FeMoO 4 composite. In conclusion, this study demonstrates the β-NiOOH/FeMoO 4 composite is a promising heterogeneous photo-Fenton catalyst. [Display omitted] • Microspheres with special particle accumulation surface structure were prepared. • The doped of Fe enables NiOOH to crystallize stable into β phase. • The degradation efficiency of MB can reach 99.5% in 18 min. • The generation potential of ·OH was indirectly determined by the coumarin fluorescence probing technique. [ABSTRACT FROM AUTHOR]