In this work the photocatalytic activity of TiO2-SiO2 thin films co-doped with Fe3+ and thio-urea in the degradation of the gaseous formaldehyde was investigaged by indoor and outdoor visible lights. The films were sy...In this work the photocatalytic activity of TiO2-SiO2 thin films co-doped with Fe3+ and thio-urea in the degradation of the gaseous formaldehyde was investigaged by indoor and outdoor visible lights. The films were synthesized by Peroxo Titanic Acid (PTA) method. The physicochemical properties of prepared samples were characterized using SEM and UV-vis absorption spectroscopy. It was found that the average film thickness of all coated samples was about 394 ± 5 nm. The band gap energy of un-doped and co-doped photocatalysts was 3.08 and 2.88 eV, respectively. The photocatalytic experimental results showed that the co-doped TiO2-SiO2 thin film yield higher photocatalytic efficiency.? Under the outdoor light (sunlight in the shade condition) irradiation, with the initial concentrations of formaldehyde of 1000, 3000 and 5000 ppmV, the efficiencies of formaldehyde degradation were 94.7 %, 89.5% and 85.1 %, respectively. Under the indoor light (the fluorescent lamp) irradiation, with the same formaldehyde initial concentrations, the photocatalytic activities were 87.4%, 85.3% and 81.5%, respectively.展开更多
Titanic acid nanotubes(H_(2)Ti_(2)O_(4)(OH)_(2))were surface-modified with cetyl alcohol through dehydration reaction because of existence of Ti–OH.The modified nanotubes were characterized by transmission electron m...Titanic acid nanotubes(H_(2)Ti_(2)O_(4)(OH)_(2))were surface-modified with cetyl alcohol through dehydration reaction because of existence of Ti–OH.The modified nanotubes were characterized by transmission electron microscopy(TEM),Fourier Transform Infrared(FT-IR)spectrometry and pho-toluminescence(PL)spectra.The results indicate that the modified nanotubes can be easily dis-persed into organic solvent such as chloroform and toluene in contrast with the unmodified nanotubes,which makes it easier to be assembled by LB technique.Moreover,the Ti-O-CH_(2)(CH_(2))_(14)CH_(3) on the surface of the nanotubes can hinder the adsorption of water and consequently the photoluminescence property of the nanotubes can be stabilized.Even though kept in humid condition or in air for a long time,the modified nanotubes also maintain the special photoluminescence property in the visible region.展开更多
【选注者言:春节的爆竹声,连绵不断,甚至延续到半夜,到凌晨。我失眠了,但心情却并不坏。爆竹一声除旧,桃符万户更新!现在是凌晨两点,英语称之为small hours,我披衣起身,打开电脑,在网上浏览起来。读到一篇短文,令我精神抖擞,睡意全消。...【选注者言:春节的爆竹声,连绵不断,甚至延续到半夜,到凌晨。我失眠了,但心情却并不坏。爆竹一声除旧,桃符万户更新!现在是凌晨两点,英语称之为small hours,我披衣起身,打开电脑,在网上浏览起来。读到一篇短文,令我精神抖擞,睡意全消。泰坦尼克巨轮已经沉没87个寒暑了,人们还在银幕上演绎她的故事,观者垂泪;人们还在聆听她的汽笛声,听众伤感。我是一个英语教师,细品本文,觉得本文造句非常讲究,用的大多是“拖泥带水”的长句,作者很懂修辞,这种“欲休还说”的句式不是很好地衬托渲染了今人怀旧时的那种缠绵悱恻的心绪吗?比如下句就很典型,我读之再三: When they were made the whistles weighed 750 pounds(340 kg)and could be heard more than 10 miles(16 km)away, according to the St. Paul Convention and Visitors Bureau, which hosted Saturday's event. 编辑先生,读者同志,不知你们是否同意我的以上分析。如果你们不同意,那么,是不是我过于善感了?】展开更多
文摘In this work the photocatalytic activity of TiO2-SiO2 thin films co-doped with Fe3+ and thio-urea in the degradation of the gaseous formaldehyde was investigaged by indoor and outdoor visible lights. The films were synthesized by Peroxo Titanic Acid (PTA) method. The physicochemical properties of prepared samples were characterized using SEM and UV-vis absorption spectroscopy. It was found that the average film thickness of all coated samples was about 394 ± 5 nm. The band gap energy of un-doped and co-doped photocatalysts was 3.08 and 2.88 eV, respectively. The photocatalytic experimental results showed that the co-doped TiO2-SiO2 thin film yield higher photocatalytic efficiency.? Under the outdoor light (sunlight in the shade condition) irradiation, with the initial concentrations of formaldehyde of 1000, 3000 and 5000 ppmV, the efficiencies of formaldehyde degradation were 94.7 %, 89.5% and 85.1 %, respectively. Under the indoor light (the fluorescent lamp) irradiation, with the same formaldehyde initial concentrations, the photocatalytic activities were 87.4%, 85.3% and 81.5%, respectively.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.90306010 and 20371015)State Key Basic Research'973'Plan of China(Grant No.2002CCC02700).
文摘Titanic acid nanotubes(H_(2)Ti_(2)O_(4)(OH)_(2))were surface-modified with cetyl alcohol through dehydration reaction because of existence of Ti–OH.The modified nanotubes were characterized by transmission electron microscopy(TEM),Fourier Transform Infrared(FT-IR)spectrometry and pho-toluminescence(PL)spectra.The results indicate that the modified nanotubes can be easily dis-persed into organic solvent such as chloroform and toluene in contrast with the unmodified nanotubes,which makes it easier to be assembled by LB technique.Moreover,the Ti-O-CH_(2)(CH_(2))_(14)CH_(3) on the surface of the nanotubes can hinder the adsorption of water and consequently the photoluminescence property of the nanotubes can be stabilized.Even though kept in humid condition or in air for a long time,the modified nanotubes also maintain the special photoluminescence property in the visible region.
文摘【选注者言:春节的爆竹声,连绵不断,甚至延续到半夜,到凌晨。我失眠了,但心情却并不坏。爆竹一声除旧,桃符万户更新!现在是凌晨两点,英语称之为small hours,我披衣起身,打开电脑,在网上浏览起来。读到一篇短文,令我精神抖擞,睡意全消。泰坦尼克巨轮已经沉没87个寒暑了,人们还在银幕上演绎她的故事,观者垂泪;人们还在聆听她的汽笛声,听众伤感。我是一个英语教师,细品本文,觉得本文造句非常讲究,用的大多是“拖泥带水”的长句,作者很懂修辞,这种“欲休还说”的句式不是很好地衬托渲染了今人怀旧时的那种缠绵悱恻的心绪吗?比如下句就很典型,我读之再三: When they were made the whistles weighed 750 pounds(340 kg)and could be heard more than 10 miles(16 km)away, according to the St. Paul Convention and Visitors Bureau, which hosted Saturday's event. 编辑先生,读者同志,不知你们是否同意我的以上分析。如果你们不同意,那么,是不是我过于善感了?】
