A series of phosphorus-modified titanium dioxide samples with varying P/Ti atomic ratio were conveniently prepared via a conventional solgel route. The effects of phosphorus content and calcination temperature on the ...A series of phosphorus-modified titanium dioxide samples with varying P/Ti atomic ratio were conveniently prepared via a conventional solgel route. The effects of phosphorus content and calcination temperature on the crystalline structure, grain growth, surface area, and the photocatalytic activity of P-modified TiO2 were investigated. The XRD results showed that P species slow down the particle growth of anatase and increase the anatase-to-rutile phase transformation temperature to more than 900°C. Kinetic studies on the P-modified TiO2 to degraded 4-chlorophenol had found that the TP5500 prepared by adopting a P/Ti atomic ratio equal to 0.05 and calcined at 500°C had an apparent rate constant equal to 0.0075 min 1, which is superior to the performance of a commercial photocatalyst Degussa P25 Kapp = 0.0045 min 1 and of unmodified TiO2 （TP0500） Kapp = 0.0022 min 1. From HPLC analyses, various hydroxylated intermediates formed during oxidation had been identified, including hydroquinone （HQ）, benzoquinone （BQ） and （4CC） 4-chlorocatechol as main products. Phytotoxicity was assessed before and after irradiation against seed germination of tomato （Lycopersicon esculentum） whereas acute toxicity was assessed by using Folsomia candida as the test organism. Intermediates products were all less toxic than 4-chlorophenol and a significant removal of the overall toxicity was accomplished展开更多
Recently,self-powered ultraviolet photodetectors(UV PDs)based on SnO_(2)have gained increasing interest due to its feature of working continuously without the need for external power sources.Nevertheless,the productio...Recently,self-powered ultraviolet photodetectors(UV PDs)based on SnO_(2)have gained increasing interest due to its feature of working continuously without the need for external power sources.Nevertheless,the production of the majority of these existing UV PDs necessitates additional manufacturing stages or intricate processes.In this work,we present a facile,cost-effective approach for the fabrication of a self-powered UV PD based on p-Si/n-SnO_(2)junction.The self-powered device was achieved simply by integrating a p-Si substrate with a n-type SnO_(2)microbelt,which was synthesized via the chemical vapor deposition(CVD)method.The high-quality feature,coupled with the belt-like shape of the SnO_(2)microbelt enables the favorable contact between the n-type SnO_(2)and p-type silicon.The built-in electric field created at the interface endows the self-powered performance of the device.The p-Si/n-SnO_(2)junction photodetector demonstrated a high responsivity(0.12 mA/W),high light/dark current ratio(>103),and rapid response speed at zero bias.This method offers a practical way to develop cost-effective and high-performance self-powered UV PDs.展开更多
Titanium dioxide nanotubes(TNTs)were prepared and used as catalysts for degradation of humic acid by titanium dioxide nanotubes/UV/O3.With a view of kinetics,the effect of calcination temperature and the synergistic e...Titanium dioxide nanotubes(TNTs)were prepared and used as catalysts for degradation of humic acid by titanium dioxide nanotubes/UV/O3.With a view of kinetics,the effect of calcination temperature and the synergistic effect of photocatalysis and ozonation were analyzed.The influences of reaction temperature,original pH value,dosage of TNTs and dosage of ozone on the reaction kinetics were also investigated,and the reaction kinetics model was established.The result showed that photocatalysis and ozonation had a good synergistic effect and the best reaction temperature of TNTs was 400℃.The TOC removal of humic acid followed zero-order kinetics.In the model,the best reaction kinetics k was obtained under the condition with original pH value of 7.35,TNTs dosage of 0.806 g·L-1 and ozone dosage of 0.49 g·h-1.It was 0.8095 mg·L-1·min-1 when the reaction temperature was 25℃ while 0.8231 mg·L-1·min-1 at 30℃.The theoretical predictions were in good agreement with the experimental data.展开更多
文摘A series of phosphorus-modified titanium dioxide samples with varying P/Ti atomic ratio were conveniently prepared via a conventional solgel route. The effects of phosphorus content and calcination temperature on the crystalline structure, grain growth, surface area, and the photocatalytic activity of P-modified TiO2 were investigated. The XRD results showed that P species slow down the particle growth of anatase and increase the anatase-to-rutile phase transformation temperature to more than 900°C. Kinetic studies on the P-modified TiO2 to degraded 4-chlorophenol had found that the TP5500 prepared by adopting a P/Ti atomic ratio equal to 0.05 and calcined at 500°C had an apparent rate constant equal to 0.0075 min 1, which is superior to the performance of a commercial photocatalyst Degussa P25 Kapp = 0.0045 min 1 and of unmodified TiO2 （TP0500） Kapp = 0.0022 min 1. From HPLC analyses, various hydroxylated intermediates formed during oxidation had been identified, including hydroquinone （HQ）, benzoquinone （BQ） and （4CC） 4-chlorocatechol as main products. Phytotoxicity was assessed before and after irradiation against seed germination of tomato （Lycopersicon esculentum） whereas acute toxicity was assessed by using Folsomia candida as the test organism. Intermediates products were all less toxic than 4-chlorophenol and a significant removal of the overall toxicity was accomplished
基金support for this research was provided by the High-Level Scientific Research Cultivation Project at Hubei Minzu University,with the grant identifier PY22001the Guiding Projects from the Department of Education in Hubei Province,identified by the grant number B2018088.
文摘Recently,self-powered ultraviolet photodetectors(UV PDs)based on SnO_(2)have gained increasing interest due to its feature of working continuously without the need for external power sources.Nevertheless,the production of the majority of these existing UV PDs necessitates additional manufacturing stages or intricate processes.In this work,we present a facile,cost-effective approach for the fabrication of a self-powered UV PD based on p-Si/n-SnO_(2)junction.The self-powered device was achieved simply by integrating a p-Si substrate with a n-type SnO_(2)microbelt,which was synthesized via the chemical vapor deposition(CVD)method.The high-quality feature,coupled with the belt-like shape of the SnO_(2)microbelt enables the favorable contact between the n-type SnO_(2)and p-type silicon.The built-in electric field created at the interface endows the self-powered performance of the device.The p-Si/n-SnO_(2)junction photodetector demonstrated a high responsivity(0.12 mA/W),high light/dark current ratio(>103),and rapid response speed at zero bias.This method offers a practical way to develop cost-effective and high-performance self-powered UV PDs.
文摘Titanium dioxide nanotubes(TNTs)were prepared and used as catalysts for degradation of humic acid by titanium dioxide nanotubes/UV/O3.With a view of kinetics,the effect of calcination temperature and the synergistic effect of photocatalysis and ozonation were analyzed.The influences of reaction temperature,original pH value,dosage of TNTs and dosage of ozone on the reaction kinetics were also investigated,and the reaction kinetics model was established.The result showed that photocatalysis and ozonation had a good synergistic effect and the best reaction temperature of TNTs was 400℃.The TOC removal of humic acid followed zero-order kinetics.In the model,the best reaction kinetics k was obtained under the condition with original pH value of 7.35,TNTs dosage of 0.806 g·L-1 and ozone dosage of 0.49 g·h-1.It was 0.8095 mg·L-1·min-1 when the reaction temperature was 25℃ while 0.8231 mg·L-1·min-1 at 30℃.The theoretical predictions were in good agreement with the experimental data.
