Bi2Te3 nanosheets promoted Pd for ethylene glycol electrooxidation both in the dark and under visible light irradiation.

Ethylene glycol electrooxidation catalyzed by Pd nanoparticles was found to be largely improved by Bi2Te3 nanosheets both in the dark and under visible light irradiation.

Enhanced reductive debromination of decabromodiphenyl ether by organic-attapulgite supported Fe/Pd nanoparticles: Synergetic effect and mechanism.

Effective removal of polybrominated diphenyl ethers (PBDEs) from the environment is essential for the ecosystem and human health. Reductive debromination of PBDEs by nanoscale zerovalent iron (nZVI) has become an important technology. However, the agglomeration and low persistence catalytic activity of nZVI particles have become urgent problems to be improved. Herein, we report the first application of a new organo-attapulgite (OA) supported Fe/Pd nanoparticles (OA-Fe/Pd) composite for decabromodiphenyl ether (BDE209) removal. BDE209 was efficiently removed using OA-Fe/Pd with a reaction rate that was 9.97 times greater than that of the nZVI due to the synergetic effect of support material OA and Pd loading. OA could prevent nZVI particles from agglomeration and adsorb BDE209 molecules to its surface. Pd could supply atomic hydrogen and also prevent the oxidation of nZVI particles. The degradation of BDE209 by OA-Fe/Pd was affected by many factors and followed pseudo first-order kinetics. The degradation of BDE209 by OA-Fe/Pd underwent a stepwise debromination manner with the H-transfer dominant mechanism. BDE209 (25 mg∙L-1) could be degraded to penta-BDEs to diphenyl ether (DE) by 3.0 g∙L-1 OA-Fe/Pd within 240 min under neutral condition. This study provides some inspiration for improving the removal efficiency of PBDEs with nZVI-based materials.

Highly efficient debromination of 4,4'-dibrominated diphenyl ether by organic palygorskite-supported Pd/Fe nanoparticles.

Organic palygorskite (OP)-supported Pd/Fe nanoparticles composite (OP-Pd/Fe) was prepared by stepwise reduction method. The removal capacity of 4,4'-dibrominated diphenyl ether (BDE15) by OP-Pd/Fe was compared with other various materials. For better understanding the possible mechanism, the synthesized and reacted OP-Pd/Fe materials were characterized by TEM, SEM, XRD, and XPS, respectively. The effects of major influencing parameters on the degradation of BDE15 were also studied. Benefit from the synergistic effect of the carrier and bimetallic nanoparticles, BDE15 could be completely debrominated into diphenyl ether (DE) under suitable conditions. A two-stage adsorption/debromination removal mechanism was proposed. The degradation of BDE15 with OP-Pd/Fe was mainly stepwise debromination reaction, and hydrogen transfer mode was assumed as the dominated debromination mechanism. The removal process fitted well to the pseudo first-order kinetic equation. The observed rate constants increased with increasing Pd loading and OP-Pd/Fe dosage while decreased with increasing initial BDE15 concentration, the tetrahydrofuran/water ratio, and the initial pH of the solution. The work provides a new approach for the treatment of PBDEs pollution.

Redox response, antibacterial and drug package capacities of chitosan-α-lipoic acid conjugates.

Chitosan-α-lipoic acid (CS-LA) conjugates were prepared by amino reaction. The methotrexate (MTX) was successfully loaded within CS-LA copolymer by the ring-opening polymerizations of disulfide bond under the action of reducing agent. The obtained copolymer was investigated by fourier transform infrared spectrometer (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and nuclear magnetic resonance (1H NMR) analysis. The ring-opening polymerization process effected on rheological properties were studied. The graft of LA increased the apparent viscosity of CS-LA, and the loaded of MTX by redox reduced its apparent viscosity enormously. The load of MTX under the action of DTT decreased the apparent viscosity and moduli of CS-LA-MTX hydrogel. In dynamic oscillatory experiment, the package of MTX reduced the rigidity of CS-LA and damaged the gel structure of CS-LA. The antimicrobial ability of CS-LA against E. coli was processed by the inhibition zone and growth curves. The modification of LA raised the antibacterial activity of CS-LA. The cytotoxicity assay of CS-LA-MTX to prostate cancer cells (RM-1) was examined. The load of MTX within CS-LA-MTX greatly enhanced the cytotoxicity to RM-1 cells. In summary, CS-LA hydrogel may provide a new copolymer carrier for drug package in food and biomedical application.

In vitro and in silico investigations of the binding interactions between chlorophenols and trypsin.

Being the first-degree toxic pollutants, chlorophenols (CP) have potential carcinogenic and mutagenic activity and toxicity. Since there still lacks studies on molecular interactions of chlorophenols with trypsin, one major binding target of many exogenous environmental pollutants, the binding interactions between five chlorophenols, 2-CP, 2,6-DCP, 2,4,6-TCP, 2,4,6-TCP, 2,3,4,6-TCP and PCP and trypsin were characterized by the combination of multispectroscopic techniques and molecular modeling. The chlorophenols bind at the one main site of trypsin and the binding induces the changes of microenvironment and global conformations of trypsin. Different number of chloride atoms significantly affects the binding and the binding constants KA ranks as KA (2-CP) < KA (2,6-DCP) ≈ KA (2,4,6-TCP) < KA (2,3,4,6-TCP) < KA (PCP). These chlorophenols interacts with trypsin mainly through hydrophobic interactions and via hydrogen bonding interactions and aromatic-aromatic π-π stacking interaction. Our results offer insights into the binding mechanism of chlorophenols with trypsin and provide important information for possible toxicity risk of chlorophenols to human health.