Capacity of the silver-doped TiO2 under UV-C light to restrain cyanobacterial growth was explored with Anabaena sp. PCC 7120 and Microcystis aeruginosa as test species. The survival, chlorophyll bleaching, photosynthe...Capacity of the silver-doped TiO2 under UV-C light to restrain cyanobacterial growth was explored with Anabaena sp. PCC 7120 and Microcystis aeruginosa as test species. The survival, chlorophyll bleaching, photosynthetic activity, DNA breakages, antioxidant enzyme activities, lipid peroxidation, and cellular morphologic structure of test cyanobacteria were analyzed. The results indicate that the test cyanobacteria with UV-C photocatalysis by silver-doped TiO2 sufferd from effects of reactive oxygen species, which promote the damage of the cell wall and the peroxidation of cell membranes, and subsequently, aggravate the losses of cell organelle and viability. The results suggest that UV-C photocatalysis by the silver ions doped TiO2 could be a promising method to prevent fast and excessive growth of cyanobacteria in eutrophic water sources.展开更多
Photocatalytic reduction of CO2 by water was performed in the presence of a Ag/TiO2 catalyst under illumination by lamps with different wavelengths(254,365,and 400 nm).The yields of the main products(methane and metha...Photocatalytic reduction of CO2 by water was performed in the presence of a Ag/TiO2 catalyst under illumination by lamps with different wavelengths(254,365,and 400 nm).The yields of the main products(methane and methanol)were higher with the 254 nm lamp than with the 365 lamp while no products were observed with the 400 nm lamp.This was because the electron-hole generation rate increased with increasing energy of irradiation(decreasing wavelength)and there were higher densities of electron states at higher energies in TiO2. The increased efficiency of electron-hole generation with a shorter wavelength irradiation increased the efficiency of the catalyst.The energy of the electrons excited by visible light(400 nm)was too low for CO2 photocatalytic reduction.展开更多
Using tetrabutyl titanate as the precursor, silver nitrate as the load agent, silver-doped titanium dioxide coating film was prepared by sol-gel method. Three agent samples were characterized by X-ray diffraction （XR...Using tetrabutyl titanate as the precursor, silver nitrate as the load agent, silver-doped titanium dioxide coating film was prepared by sol-gel method. Three agent samples were characterized by X-ray diffraction （XRD） analysis to investigate the crystal structure, which confirmed a synergistic antibacterial effect. The antibacterial and preservative effects of silver-doped titanium dioxide coating film on Nanfeng citrus were investigated preliminarily. Nutritional indicators of ripe Nanfeng citrus before and after preservation were detected to investigate the preservative properties of silver-doped titanium dioxide coating film and compare the effects of different components of composite coating film. The results showed that Ag＋/TiO2 composite coating film exhibited high antibacterial and preservative effects on Nanfeng citrus under visible light illumination condition.展开更多
This work investigated the influence of silver plasmon and reduced graphene oxide(r GO)on the photoelectrochemical performance(PEC)of Zn O thin films synthesized by the sol-gel method.The physicochemical properties of...This work investigated the influence of silver plasmon and reduced graphene oxide(r GO)on the photoelectrochemical performance(PEC)of Zn O thin films synthesized by the sol-gel method.The physicochemical properties of the obtained photo-anodes were systematically studied by using several characterization techniques.The x-ray diffraction analysis showed that all samples presented hexagonal wurtzite structure with a polycrystalline nature.Raman and energy dispersive x-ray(EDX)studies confirmed the existence of both Ag and r GO in Zn O:Ag/r GO thin films.The estimated grain size obtained from scanning electron microscopy(SEM)analysis decreased with Ag doping,then increased to a maximum value after r GO addition.The UV-vis transmission spectra of the as-prepared Zn O:Ag and Zn O:Ag/r GO thin films have shown a reduction in the visible range with a redshift at the absorption edges.The bandgaps were estimated to be around 3.17 e V,2.7 e V,and 2.52 e V for Zn O,Zn O:Ag,and Zn O:Ag/r GO,respectively.Moreover,the electrical measurements revealed that the charge exchange processes were enhanced at the Zn O:Ag/r GO/electrolyte interface,accompanied by an increase in the(PEC)performance compared to Zn O and Zn O:Ag photo-anodes.Consequently,the photocurrent density of Zn O:Ag/r GO(0.2 m A·cm^(-2)) was around 4 and 2.22 times higher than photo-anodes based on undoped Zn O(0.05 m A·cm^(-2)) and Zn O:Ag(0.09 m A·cm^(-2)),respectively.Finally,from the flat band potential and donor density,deduced from the Mott-Schottky,it was clear that all the samples were n-type semiconductors with the highest carrier density for the Zn O:Ag/r GO photo-anode.展开更多
基金Funded by the National Natural Science Foundation of China(No.30540070)the Specialized Research Fund for the Doctoral Program of Higher Education(No.20060487018)
文摘Capacity of the silver-doped TiO2 under UV-C light to restrain cyanobacterial growth was explored with Anabaena sp. PCC 7120 and Microcystis aeruginosa as test species. The survival, chlorophyll bleaching, photosynthetic activity, DNA breakages, antioxidant enzyme activities, lipid peroxidation, and cellular morphologic structure of test cyanobacteria were analyzed. The results indicate that the test cyanobacteria with UV-C photocatalysis by silver-doped TiO2 sufferd from effects of reactive oxygen species, which promote the damage of the cell wall and the peroxidation of cell membranes, and subsequently, aggravate the losses of cell organelle and viability. The results suggest that UV-C photocatalysis by the silver ions doped TiO2 could be a promising method to prevent fast and excessive growth of cyanobacteria in eutrophic water sources.
基金supported by the Czech Ministry of Education,Youth and Sports(research project LA08050)the Grant Agency of theCzech Republic(GA 104/09/0694)
文摘Photocatalytic reduction of CO2 by water was performed in the presence of a Ag/TiO2 catalyst under illumination by lamps with different wavelengths(254,365,and 400 nm).The yields of the main products(methane and methanol)were higher with the 254 nm lamp than with the 365 lamp while no products were observed with the 400 nm lamp.This was because the electron-hole generation rate increased with increasing energy of irradiation(decreasing wavelength)and there were higher densities of electron states at higher energies in TiO2. The increased efficiency of electron-hole generation with a shorter wavelength irradiation increased the efficiency of the catalyst.The energy of the electrons excited by visible light(400 nm)was too low for CO2 photocatalytic reduction.
基金Supported by National Natural Science Foundation of China(31360466)Science and Technology Support Program of Jiangxi Province(20142BBF6002)
文摘Using tetrabutyl titanate as the precursor, silver nitrate as the load agent, silver-doped titanium dioxide coating film was prepared by sol-gel method. Three agent samples were characterized by X-ray diffraction （XRD） analysis to investigate the crystal structure, which confirmed a synergistic antibacterial effect. The antibacterial and preservative effects of silver-doped titanium dioxide coating film on Nanfeng citrus were investigated preliminarily. Nutritional indicators of ripe Nanfeng citrus before and after preservation were detected to investigate the preservative properties of silver-doped titanium dioxide coating film and compare the effects of different components of composite coating film. The results showed that Ag＋/TiO2 composite coating film exhibited high antibacterial and preservative effects on Nanfeng citrus under visible light illumination condition.
基金funded by Tunisian Ministry of Higher Education and Scientific Research through the budget allowed to the implied Tunisian labs。
文摘This work investigated the influence of silver plasmon and reduced graphene oxide(r GO)on the photoelectrochemical performance(PEC)of Zn O thin films synthesized by the sol-gel method.The physicochemical properties of the obtained photo-anodes were systematically studied by using several characterization techniques.The x-ray diffraction analysis showed that all samples presented hexagonal wurtzite structure with a polycrystalline nature.Raman and energy dispersive x-ray(EDX)studies confirmed the existence of both Ag and r GO in Zn O:Ag/r GO thin films.The estimated grain size obtained from scanning electron microscopy(SEM)analysis decreased with Ag doping,then increased to a maximum value after r GO addition.The UV-vis transmission spectra of the as-prepared Zn O:Ag and Zn O:Ag/r GO thin films have shown a reduction in the visible range with a redshift at the absorption edges.The bandgaps were estimated to be around 3.17 e V,2.7 e V,and 2.52 e V for Zn O,Zn O:Ag,and Zn O:Ag/r GO,respectively.Moreover,the electrical measurements revealed that the charge exchange processes were enhanced at the Zn O:Ag/r GO/electrolyte interface,accompanied by an increase in the(PEC)performance compared to Zn O and Zn O:Ag photo-anodes.Consequently,the photocurrent density of Zn O:Ag/r GO(0.2 m A·cm^(-2)) was around 4 and 2.22 times higher than photo-anodes based on undoped Zn O(0.05 m A·cm^(-2)) and Zn O:Ag(0.09 m A·cm^(-2)),respectively.Finally,from the flat band potential and donor density,deduced from the Mott-Schottky,it was clear that all the samples were n-type semiconductors with the highest carrier density for the Zn O:Ag/r GO photo-anode.
