BiOI powder has been proved to be an efficient photocatalyst, but the difficulty in removing it from water after reaction limits its application in real water treatment. To solve this problem,a thin-film fixed-bed rea...BiOI powder has been proved to be an efficient photocatalyst, but the difficulty in removing it from water after reaction limits its application in real water treatment. To solve this problem,a thin-film fixed-bed reactor(TFFBR) was set-up by developing a BiOI thin film on glass fiber cloth(GFC). The composition and structure of the as-prepared films were characterized with X-ray diffraction, X-ray photoelectron spectroscopy, field emission microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy. The BiOI thin film was made by painting a silica sol containing BiOI on GFC, which could be tailored to desired sizes to accommodate the TFFBR. The mass of BiOI on the GFC increased with the number of iterations of the painting process. SiO2 sol glued the BiOI particles tightly onto the GFC,making the thin film strong enough to resist fluid flushing in the TFFBR. The photocatalytic activity of the BiOI thin film was investigated by degrading bisphenol A(BPA) under simulated sunlight. Ninety eight percent of BPA(20 mg/L in 2 L) was degraded by the BiOI thin film sample of seven layers(GFC-7) on the TFFBR within 8 hr irradiation. The GFC-7 displayed good photocatalytic ability toward artificial sewage containing BPA in a wide pH range(5–9),and also demonstrated excellent durability and reusability. The working conditions were optimized and it was found that the thickness of the fluid film and residence time over the thin film were key factors affecting the photocatalytic efficiency.展开更多
Bi2WO6 was synthesized with a hydrothermal method at different pHs and used for the degradation of tetracycline （TC） in water. The mesoporous BiEWO6 prepared at pH 1 （BWO-1） displayed the highest adsorption and de...Bi2WO6 was synthesized with a hydrothermal method at different pHs and used for the degradation of tetracycline （TC） in water. The mesoporous BiEWO6 prepared at pH 1 （BWO-1） displayed the highest adsorption and degradation capacity to TC due to its large surface area and more efficient capacity to separate photogenerated electrons and holes. 97% of TC at 20 mg · L-1 was removed by BWO-1 at 0.5 g-L-1 after 120min irradiation under simulated solar light. Only 31% of the total organic carbon （TOC） was removed after 360 min irradiation although the TC removal reached 100%, suggesting that TC was mainly transformed to intermediate products rather than completely mineralized. The inter- mediates were identified by high-performance liquid chromatography-time of flight-mass spectrometry （HPLC-TOF-MS） and possible photodegradation path- ways were proposed.展开更多
基金supported by the National Science Foundation of China (Nos. 21737003, 21677081)the Tianjin Municipal Science and Technology Commission (Nos. 16PTSYJC00020, 17JCYBJC23200)+2 种基金the Ministry of Science and Technology (No. 2017ZX07301002)the Yangtze River scholar program111 program, Ministry of Education, China (No. T2017002)
文摘BiOI powder has been proved to be an efficient photocatalyst, but the difficulty in removing it from water after reaction limits its application in real water treatment. To solve this problem,a thin-film fixed-bed reactor(TFFBR) was set-up by developing a BiOI thin film on glass fiber cloth(GFC). The composition and structure of the as-prepared films were characterized with X-ray diffraction, X-ray photoelectron spectroscopy, field emission microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy. The BiOI thin film was made by painting a silica sol containing BiOI on GFC, which could be tailored to desired sizes to accommodate the TFFBR. The mass of BiOI on the GFC increased with the number of iterations of the painting process. SiO2 sol glued the BiOI particles tightly onto the GFC,making the thin film strong enough to resist fluid flushing in the TFFBR. The photocatalytic activity of the BiOI thin film was investigated by degrading bisphenol A(BPA) under simulated sunlight. Ninety eight percent of BPA(20 mg/L in 2 L) was degraded by the BiOI thin film sample of seven layers(GFC-7) on the TFFBR within 8 hr irradiation. The GFC-7 displayed good photocatalytic ability toward artificial sewage containing BPA in a wide pH range(5–9),and also demonstrated excellent durability and reusability. The working conditions were optimized and it was found that the thickness of the fluid film and residence time over the thin film were key factors affecting the photocatalytic efficiency.
文摘Bi2WO6 was synthesized with a hydrothermal method at different pHs and used for the degradation of tetracycline （TC） in water. The mesoporous BiEWO6 prepared at pH 1 （BWO-1） displayed the highest adsorption and degradation capacity to TC due to its large surface area and more efficient capacity to separate photogenerated electrons and holes. 97% of TC at 20 mg · L-1 was removed by BWO-1 at 0.5 g-L-1 after 120min irradiation under simulated solar light. Only 31% of the total organic carbon （TOC） was removed after 360 min irradiation although the TC removal reached 100%, suggesting that TC was mainly transformed to intermediate products rather than completely mineralized. The inter- mediates were identified by high-performance liquid chromatography-time of flight-mass spectrometry （HPLC-TOF-MS） and possible photodegradation path- ways were proposed.
