Jinxiu Wang,Xue Yang,Jing Chen,Jiangjun Xian,Sugang Meng,Yi Zheng,Yu Shao,Danzhen Li
In this study, pure Ag 4 V 2 O 7 was synthesized via hydrothermal method without surfactant at different temperatures (100°C, 120°C, and 140°C) and pH values (4 and 5) for the first time. Moreover, Ag 4 V 2 O 7 nanoparticles with homogeneous size distribution about 200–300 nm can be obtained by adding polyvinylpyrrolidone to the synthesis system. Effects of hydrothermal synthesis conditions on photophysical properties and photocatalytic activity of Ag 4 V 2 O 7 were investigated systematically. Ag 4 V 2 O 7 sample prepared at 120°C and pH = 4 had the optimal photocatalytic activity among these samples, which almost completely degraded 10 ppm Rhodamine B within 3 h under visible light irradiation (420 nm < λ < 800 nm). The degradation products were measured by liquid chromatography–mass spectroscopy. The active species involved in the degradation process were analyzed by means of adding active species scavengers, electron spin resonance techniques, and photoelectrochemical experiments. A possible mechanism for photocatalytic degradation of organic pollutants on Ag 4 V 2 O 7 photocatalyst was proposed and discussed preliminarily.
Pengfei Zhu,Shasha Zhang,Mei Liu,Ming Duan,Zhaoxin Huang,Han Lu
Herein, a novel Bi 2 WO 6 /AgBr/Ag 4 V 2 O 7 double Z-scheme heterojunction photocatalytic material was synthesized by the ultrasonic-assisted coprecipitation method. When the content of AgBr in Bi 2 WO 6 /AgBr/Ag 4 V 2 O 7 is 30 wt% and the content of Ag 4 V 2 O 7 is 1 wt%, under the optimized reaction conditions, the degradation rate of Bi 2 WO 6 /AgBr/Ag 4 V 2 O 7 to oxytetracycline (OTC) reached 88.13 % within 60 min, and the photocatalytic activity decreased only slightly after repeated use for three times, other than that, the toxicity of OTC to wheat decreased significantly after degradation. The morphology, composition, crystal structure and visible light absorption capacity of the samples are investigated by a series of characterization techniques. Furthermore, free radical capture experiment, electron paramagnetic resonance (EPR) experiment and liquid chromatography-mass spectrometry (LC-MS) were used to explore the possible photocatalytic mechanism and degradation path of OTC. The results show that the improvement of photocatalytic activity is attributed to the construction of a double Z-scheme heterojunction, which provides a more effective structural space for the separation of photogenerated e - -h + pairs. This study provides a new idea for the separation of photogenerated e - -h + pairs and broadens the response range of visible light, and proposes a new strategy for the environmental treatment of photocatalysts.
危险品化学品经营许可证（带存储）