The graft copolymerization of 4-vinyl pyridine （4VP） onto nylon-6 （PA6） was studied by using potassium diperiodatonickelate（IV） （DPN）-PA6 redox system in alkaline medium. The structures of graft copolymers wer...The graft copolymerization of 4-vinyl pyridine （4VP） onto nylon-6 （PA6） was studied by using potassium diperiodatonickelate（IV） （DPN）-PA6 redox system in alkaline medium. The structures of graft copolymers were confirmed by Fourier transfer infrared spectroscopy （FTIR） and X-ray diffraction. The properties of graft copolymers were investigated by thermogravimetric analysis （TGA）. A mechanism was proposed to explain the generation of radicals and the initiation. The effects of reaction variables, such as the initiator concentration, the ratio of 4VP to PA6, pH as well as reaction temperature and time were investigated. Graft copolymers with high grafting efficiency （〉95%） were obtained, which indicated that DPN-PA6 redox system is an efficient initiator for this graft copolymerization. The quaternized PA6-g-P4VP （QPAVP） was proved to be an excellent adsorbent to heavy metal ions.展开更多
Surface junctions between Bi OBr and BiVO4 were synthesized. The BiOBr/BiVO4 with 1 wt.%of Bi OBr exhibited the highest photocatalytic activity in the degradation of Rh B under visible-light irradiation. It was found ...Surface junctions between Bi OBr and BiVO4 were synthesized. The BiOBr/BiVO4 with 1 wt.%of Bi OBr exhibited the highest photocatalytic activity in the degradation of Rh B under visible-light irradiation. It was found that the highly efficient adsorption of Rh B molecules via the electrostatic attraction between Br-and cationic ／N（Et）2 group played a key role for the high photocatalytic activities of BiOBr/BiVO4. This efficient adsorption promoted the N-deethylation of Rh B and thus accelerated the photocatalytic degradation of Rh B.Moreover, the metal-to-metal charge transfer（MMCT） mechanism was proposed, which revealed the concrete path paved with Bi–O–Bi chains for the carrier migration in BiOBr/BiVO4. The interaction between photoexcited Rh B＊ and the Bi^（3＋） in BiVO4 provided the driving force for the migration of photo-generated carriers along the Bi–O–Bi chains. This work has not only demonstrated the important role of efficient adsorption in the photocatalytic degradation of organic contaminants, but also developed a facile strategy to improve the efficiency of photocatalysts.展开更多
文摘The graft copolymerization of 4-vinyl pyridine （4VP） onto nylon-6 （PA6） was studied by using potassium diperiodatonickelate（IV） （DPN）-PA6 redox system in alkaline medium. The structures of graft copolymers were confirmed by Fourier transfer infrared spectroscopy （FTIR） and X-ray diffraction. The properties of graft copolymers were investigated by thermogravimetric analysis （TGA）. A mechanism was proposed to explain the generation of radicals and the initiation. The effects of reaction variables, such as the initiator concentration, the ratio of 4VP to PA6, pH as well as reaction temperature and time were investigated. Graft copolymers with high grafting efficiency （〉95%） were obtained, which indicated that DPN-PA6 redox system is an efficient initiator for this graft copolymerization. The quaternized PA6-g-P4VP （QPAVP） was proved to be an excellent adsorbent to heavy metal ions.
基金supported by National Basic Research Program (973) of China (No. 2013CB933200)the National Natural Science Foundation of China (Nos. 21671197, 51472260)the Research Grant (No. 16ZR1440800) from Shanghai Science and Technology Commission
文摘Surface junctions between Bi OBr and BiVO4 were synthesized. The BiOBr/BiVO4 with 1 wt.%of Bi OBr exhibited the highest photocatalytic activity in the degradation of Rh B under visible-light irradiation. It was found that the highly efficient adsorption of Rh B molecules via the electrostatic attraction between Br-and cationic ／N（Et）2 group played a key role for the high photocatalytic activities of BiOBr/BiVO4. This efficient adsorption promoted the N-deethylation of Rh B and thus accelerated the photocatalytic degradation of Rh B.Moreover, the metal-to-metal charge transfer（MMCT） mechanism was proposed, which revealed the concrete path paved with Bi–O–Bi chains for the carrier migration in BiOBr/BiVO4. The interaction between photoexcited Rh B＊ and the Bi^（3＋） in BiVO4 provided the driving force for the migration of photo-generated carriers along the Bi–O–Bi chains. This work has not only demonstrated the important role of efficient adsorption in the photocatalytic degradation of organic contaminants, but also developed a facile strategy to improve the efficiency of photocatalysts.
