Modulating the Electronic Coordination Configuration and d-Band Center in Homo-Diatomic Fe2N6 Catalysts for Enhanced Peroxymonosulfate Activation.

The electronic coordination configuration of metal active sites and the reaction mechanism were investigated by constructing homo-diatomic Fe sites for visible-light-assisted heterogeneous peroxymonosulfate (PMS) activation. A novel Fe2N6 catalyst was synthesized by selecting uniform pyridinic-N of graphitic carbon nitride (g-C3N4) as anchoring sites. The results demonstrated that homo-diatomic Fe sites modulated the d-band center and electron delocalization and thus enhanced the PMS activation kinetics (3.58 times vs single-atom Fe catalyst) with kobs of 0.111 min-1 owing to the synergistic effect between adjacent Fe atoms. New Fe-Fe coordination significantly decreased the contribution of the antibonding state in the Fe-O bond due to the coupling of the Fe-3d orbitals, which facilitated the O-O bond cleavage of the Fe2-HOO-SO3 complex with a reduced thermodynamic energy barrier of only -0.29 eV. This work provided comprehensive mechanistic insights into developing homo-diatomic catalysts governed by the coordination configuration and radical pathway for efficient heterogeneous PMS catalysis.

In situ synthesis of novel peroxo-functionalized Ti3C2Tx adsorbent for aqueous pollutants removal: Role of oxygen-containing terminal groups.

A novel peroxo-functionalized Ti3C2Tx adsorbent with abundant surface termination groups was facilely prepared in situ to remove aqueous anionic and cationic dyes. The adsorption behavior of methylene blue on peroxo-functionalized Ti3C2Tx was systematically investigated by adsorption kinetics, isotherms, and thermodynamics. Compared with Ti3C2Tx, the adsorption capacities of peroxo-functionalized Ti3C2Tx for cationic dyes methylene blue (558.0 mg g-1), rhodamine B (524.6 mg g-1) and anionic dyes methyl orange (292.6 mg g-1), congo red (258.2 mg g-1) were increased at room temperature without adjustment of pH, background ions and humic acid, etc of the contaminant solution by 7.9, 5.3, 5.9 and 4.6 times, respectively. In addition, peroxo-functionalized Ti3C2Tx could well tolerate the effects of pH, ionic strength, and humic acid. As revealed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, the adsorption mechanism of peroxo-functionalized Ti3C2Tx for anionic and cationic dyes was mainly attributed to the electrostatic interaction, hydrogen bonding interaction, and noncovalent surface-π attraction interaction. This study demonstrates a facile modification strategy for Ti3C2Tx adsorbent materials and aims to provide insights for the development of excellent Ti3C2Tx-based adsorbent materials.

Evaluation and Prediction on the Effect of Ionic Properties of Solvent Extraction Performance of Oily Sludge Using Machine Learning.

Oily sludge produced in the process of petroleum exploitation and utilization is a kind of hazardous waste that needs to be urgently dealt with in the petrochemical industry. The oil content of oily sludge is generally between 15-50% and has a great potential for oil resource utilization. However, its composition is complex, in which asphaltene is of high viscosity and difficult to separate. In this study, The oily sludge was extracted with toluene as solvent, supplemented by three kinds of ionic liquids (1-ethyl-3-methylimidazole tetrafluoroborate ([EMIM] [BF4]), 1-ethyl-3-methylimidazole trifluoro-acetate ([EMIM] [TA]), 1-ethyl-3-methylimidazole Dicyandiamide ([EMIM] [N(CN)2])) and three kinds of deep eutectic solutions (choline chloride/urea (ChCl/U), choline chloride / ethylene glycol (ChCl/EG), and choline chloride/malonic acid (ChCl/MA)). This experiment investigates the effect of physicochemical properties of the solvents on oil recovery and three machine learning methods (ridge regression, multilayer perceptron, and support vector regression) are used to predict the association between them. Depending on the linear correlation of variables, it is found that the conductivity of ionic liquid is the key characteristic affecting the extraction treatment in this system.