We synthesized a series of carbon‐supported atomic metal‐N‐C catalysts (M‐SACs: M=Mn, Fe, Co, Ni, Cu) with similar structural and physicochemical properties to uncover their catalytic activity trends and mechanisms. The peroxymonosulfate (PMS) catalytic activity trends are Fe‐SAC>Co‐SAC>Mn‐SAC>Ni‐SAC>Cu‐SAC, and Fe‐SAC displays the best single‐site kinetic value (1.65×105 min−1 mol−1) compared to the other metal‐N‐C species. First‐principles calculations indicate that the most reasonable reaction pathway for 1O2 production is PMS→OH*→O*→1O2; M‐SACs that exhibit moderate and near‐average Gibbs free energies in each reaction step have a better catalytic activity, which is the key for the outstanding performance of Fe‐SACs. This study gives the atomic‐scale understanding of fundamental catalytic trends and mechanisms of PMS‐assisted reactive oxygen species production via M‐SACs, thus providing guidance for developing M‐SACs for catalytic organic pollutant degradation.

Poly(ether sulfone) (PES) nanofibers were prepared by the gas-jet/electrospinning of its solutions in N,N-dimethylformamide (DMF). The gas used in this gasjet/electrospinning process was nitrogen. The morphology of the PES nanofibers was investigated with scanning electron microscopy. The process parameters studied in this work included the concentration of the polymer solution, the applied voltage, the tip-collector distance (TCD), the inner diameter of the needle, and the gas flow rate. It was found from experimental results that the average diameter of the electrospun PES fibers depended strongly on these process parameters. A decrease in the polymer concentration in the spinning solutions resulted in the formation of nanofibers with a smaller diameter. The use of an 18 wt % polymer solution yielded PES nanofibers with an average diameter of about 80 nm. However, a morphology of mixed bead fibers was formed when the concentration of PES in DMF was below 20 wt % during gas-jet/electrospinning. Uniform PES nanofibers with an average diameter of about 200 nm were prepared by this electrospinning with the following optimal process parameters: the concentration of PES in DMF was 25 wt %, the applied voltage was 28.8 kV, the gas flow was 10.0 L/min, the inner diameter of the needle was 0.24 mm, the TCD was 20 cm, and the flow rate was 6.0 mL/h.

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Rutin was acylated with stearic acid in the esterification reaction catalyzed by immobilized Candida antarctica lipase B (Novozym 435) in tert-amyl alcohol with and without molecular sieves. The lipophilic rutin stearate was synthesized by this method, which had a potential use in food, cosmetics, and pharmacy. The structure of rutin stearate was characterized by spectral methods of 1H NMR and 13C NMR, Fourier transform infrared, and UV-vis. The results suggested that the regioselectivity of the lipase-catalyzed esterification of rutin was specific at the C(4''')-position of the rhamnose moiety. It was found that the addition of molecular sieves increased both the reaction rate and the yield. The time effect of adding molecular sieves in the reaction system on the conversion of rutin stearate was further examined. Instead of adding molecular sieves at the beginning of the reaction, the addition of molecular sieves at 5, 18, 24, 31, and 44 h after the beginning of the reaction was also applied. The final conversion for the case to add molecular sieves at 24 h after the beginning of reaction was the highest, with the conversion yield about 46%.

This work provides a novel approach to improve not only water flux but also fouling resistance of Polyvinylidene fluoride (PVDF) membranes. PVDF/Poly(vinyl alcohol) (PVA)-blended nanofiber membranes were prepared via electrospinning method. The structure and performance of blended nanofiber membranes were characterized by scanning electron microscopy (SEM), atomic force microscope (AFM), attenuated total reflection-Fourier-transform infrared (ATR-FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), contact angle measurement, tensile mechanical measurement, and filtration experiments. These results indicate that PVA was uniformly blend in the PVDF matrix. This blended nanofiber membranes with the ridge-and-valley structure and bicontinuous phase exhibited the hydrophilic performance and super-wettability, which is reflected in a drop of water fully spread within 1.44 s. Filtration experiments showed that the blended nanofiber membranes have ultrahigh flux and low irreversible fouling ratio. In general, this work enhances the possibility of hydrophilic modification of hydrophobic PVDF membranes.