Sustainable synthesis of hydroxyl-functional porous organic framework as novel adsorbent for effective removal of organic micropollutants from water.

Organic micropollutants (OMPs) in water resources are a growing threat to aquatic ecosystems and human health. Efficient removal of polar OMPs is very challenging because of their high hydrophility. Synthesizing novel adsorbent capable of high-efficiently removing hydrophilic and hydrophobic micropollutants is highly desirable for water remediation. Here, using natural proanthocyanidin as building units, a novel hydroxyl-functional porous organic framework (denoted as PC-POF) with amphiphilic feature was synthesized through facile azo coupling reaction. Five sulfonamide antibiotics were selected as model OMPs for adsorption study. Adsorption experiments demonstrated a more rapid and efficient sulfonamides capture ability of the PC-POF than that of the most reported adsorbents due to strong hydrogen bonding, π stacking and electrostatic interactions. The PC-POF can be easily recovered and reused at least 5 times without obvious decline in adsorption performance. Moreover, experiments conducted at environmentally relevant concentrations (µg L-1) further confirmed a notable adsorption performance of the PC-POF even when the sulfonamides solution was rapidly passed through the PC-POF packed column. The PC-POF also showed good adsorption performance for other micropollutants like neonicotinoid insecticides, nitroimidazole antibiotics and triazine herbicides, indicating a promising prospect. This work provides a new strategy to construct amphiphilic adsorbent by using renewable resources for pollutants removal.

Interfacial Structural and Electronic Regulation of MoS2 for Promoting Its Kinetics and Activity of Alkaline Hydrogen Evolution.

The alkaline hydrogen evolution reaction (HER) of MoS2 is hampered by its sluggish water dissociation kinetics as well as limited edge sites. Herein, Ni3S2/MoS2 is fabricated as a model catalyst to highlight interfacial structural and electronic modulations of MoS2 for realizing its high performance in the alkaline HER. Experiments and density functional theory results demonstrate that the coupled Ni3S2 species can not only promote the adsorption and dissociation of H2O to boost the alkaline HER kinetics but also tailor the inert plane of MoS2 to create abundant unsaturated edge-like active sites, while the interfacial electron interaction can regulate the band gaps and Gibbs free energy of hydrogen adsorption of MoS2 to improve the electron conductivity as well as HER activity. Moreover, field emission scanning electron microscopy, transmission electron microscopy, Raman, ex situ synchrotron radiation X-ray absorption, and X-ray photoelectron spectroscopy results reveal the excellent structural stability of Ni3S2/MoS2 during the HER. As expected, the target Ni3S2/MoS2 achieves an ultralow overpotential of 68 mV at 10 mA cm-2, a fast alkaline HER kinetics, and remarkable durability. The proposed concept of interfacial structural and electronic reorganization could be extended to develop other functional materials.