We prepared TiO 2(anatase) and Sn doped TiO 2 nanoparticlate film by Plasma enhanced Chemical Vapor Deposition(PECVD) method. XRD and XPS experiments showed that Sn was doped into the lattice of TiO 2 with a ratio of ...We prepared TiO 2(anatase) and Sn doped TiO 2 nanoparticlate film by Plasma enhanced Chemical Vapor Deposition(PECVD) method. XRD and XPS experiments showed that Sn was doped into the lattice of TiO 2 with a ratio of n (Sn)∶ n (Ti)=1∶10 . Sn doping largely enhanced the photocatalytic activity of TiO 2 film for phenol degradation. The enhancement in photoactivity by doping was discussed, based on the characterization with AFM, FTIR and EFISPS. Sn doping produced localized level of Sn 4+ in the band gap of TiO 2, about 0.4 eV below the conduction band, which could capture photogenerated electrons and reduce O 2 adsorbed on the surface of TiO 2 film, thus accelerated the photocatalytic reaction.展开更多
Wettability is a very important property governed by both the chemical composition and the geometrical structure of solid surfaces. Super-hydrophobic surface[with water contact angle(CA) larger than 150°] have be...Wettability is a very important property governed by both the chemical composition and the geometrical structure of solid surfaces. Super-hydrophobic surface[with water contact angle(CA) larger than 150°] have been extensively investigated due to their importance for industrial applications. In the present study, we describe a rather simple method for synthesizing separated alignments of polymer nanopole films, which has super-hydrophobic property with water a contact angle as high as 152.0°. Nanostructures that induce the large fraction of air on the surface cause this unique property.展开更多
Thiol-capping of CdTe nanocrystals were prepared in aqueous solution. The emission wavelengths of CdTe nanocrystals could be tuned by the refluxing time. Bioinorganic conjugates between CdTe nanocrystals and BSA were ...Thiol-capping of CdTe nanocrystals were prepared in aqueous solution. The emission wavelengths of CdTe nanocrystals could be tuned by the refluxing time. Bioinorganic conjugates between CdTe nanocrystals and BSA were formed via electrostatic/coordinate self-assembly. The photoluminescence intensity of the bioinorganic conjugates was improved obviously. BSA could stabilize the CdTe nanocrystals, and the bioinorganic conjugates at room temperature were stable for a long time. We also demonstrated that CdTe nanocrystals could be blocked with BSA and avoid the nonspecific adsorption.展开更多
The TiO 2 nanoparticle thin films have been sensitized in situ with CdS nanoparticles. The SPS measurement showed that large surface state density was present on the TiO 2 nanoparticles and the surface state can be ef...The TiO 2 nanoparticle thin films have been sensitized in situ with CdS nanoparticles. The SPS measurement showed that large surface state density was present on the TiO 2 nanoparticles and the surface state can be efficiently decreased by sensitization as well as selecting suitable heat treatment. Both the photocurrent response and the charge recombination kinetics in TiO 2 thin films were strongly influenced by trapping/detrapping of surface states. The slow photocurrent response of TiO 2 nanoparticulate thin films upon the illumination was attributed to the trap saturation effects. The semiconductor sensitization made the slow photoresponse disappeared and the steadystate photocurrent value increased drastically, which suggested that the sensitization of TiO 2 thin films with CdS could get a better charge separation and provide a simple alternative to minimize the effect of surface state on the photocurrent response.展开更多
TiO 2 nanoparticle film catalysts with different thicknesses were prepared by plasma enhanced chemical vapor deposition(PECVD) method and the surfaces were subsequently treated by TiCl 4 or O 2 plasma. Two kinds of Ti...TiO 2 nanoparticle film catalysts with different thicknesses were prepared by plasma enhanced chemical vapor deposition(PECVD) method and the surfaces were subsequently treated by TiCl 4 or O 2 plasma. Two kinds of TiO 2 films with different surface properties were obtained. Their surface microstructures and energy levels of surface states were tested by AFM, XRD, SPS. The photocatalytic activities of the catalysts were determined via photodegradation experiments of phenol. The results demonstrated that photocatalytic activities of samples whose surface was treated by O 2 plasma were greater than those treated by TiCl 4 plasma. Moreover, photodegradation ratio of phenol during the first hour catalyzed by 0.17 μm thickness TiO 2 nanoparticle film was greater than other samples. Especially, the difference of photocatalytic activities of TiO 2 nanoparticle films treated by TiCl 4 or O 2 plasma was respectively explained by energy band theory.展开更多
Dextran coated magnetic nanocomposites were prepared. A periodate oxidation method was used to further activate the magnetic dextran, forming magnetic polyaldehyde dextran, which could be conjugated to biomolecules, a...Dextran coated magnetic nanocomposites were prepared. A periodate oxidation method was used to further activate the magnetic dextran, forming magnetic polyaldehyde dextran, which could be conjugated to biomolecules, antibodes. The magnetic labeled nano scaled bioconjugates could be well blocked with BSA and exhibit high activity by ELISA and immunochromatographic strip assay.展开更多
In the present work, we prepared two kinds of quantum sized ZnO particles whose size were 3 nm(P1) and 5 nm(P2), respectively, and studied their surface properties with surface photovoltage spectroscopy(SPS) and elect...In the present work, we prepared two kinds of quantum sized ZnO particles whose size were 3 nm(P1) and 5 nm(P2), respectively, and studied their surface properties with surface photovoltage spectroscopy(SPS) and electric field induced surface photovoltage spectroscopy(EFISPS). The photovoltaic response of the two samples showed opposite dependence on external electric field. And when electric field was applied, the thresholds of photovoltaic response of the two samples were all red shifted. The results showed that the surface properties of P1 were different from those of P2, because of their different preparation process. We assigned that basic zinc acetate structure exist on the surface of P1 sample. While for P2 sample prepared by aging P1, that kind of surface structure disappeared, but the particles might be doped with lithium ions in the aging process.展开更多
文摘We prepared TiO 2(anatase) and Sn doped TiO 2 nanoparticlate film by Plasma enhanced Chemical Vapor Deposition(PECVD) method. XRD and XPS experiments showed that Sn was doped into the lattice of TiO 2 with a ratio of n (Sn)∶ n (Ti)=1∶10 . Sn doping largely enhanced the photocatalytic activity of TiO 2 film for phenol degradation. The enhancement in photoactivity by doping was discussed, based on the characterization with AFM, FTIR and EFISPS. Sn doping produced localized level of Sn 4+ in the band gap of TiO 2, about 0.4 eV below the conduction band, which could capture photogenerated electrons and reduce O 2 adsorbed on the surface of TiO 2 film, thus accelerated the photocatalytic reaction.
文摘Wettability is a very important property governed by both the chemical composition and the geometrical structure of solid surfaces. Super-hydrophobic surface[with water contact angle(CA) larger than 150°] have been extensively investigated due to their importance for industrial applications. In the present study, we describe a rather simple method for synthesizing separated alignments of polymer nanopole films, which has super-hydrophobic property with water a contact angle as high as 152.0°. Nanostructures that induce the large fraction of air on the surface cause this unique property.
文摘Thiol-capping of CdTe nanocrystals were prepared in aqueous solution. The emission wavelengths of CdTe nanocrystals could be tuned by the refluxing time. Bioinorganic conjugates between CdTe nanocrystals and BSA were formed via electrostatic/coordinate self-assembly. The photoluminescence intensity of the bioinorganic conjugates was improved obviously. BSA could stabilize the CdTe nanocrystals, and the bioinorganic conjugates at room temperature were stable for a long time. We also demonstrated that CdTe nanocrystals could be blocked with BSA and avoid the nonspecific adsorption.
文摘The TiO 2 nanoparticle thin films have been sensitized in situ with CdS nanoparticles. The SPS measurement showed that large surface state density was present on the TiO 2 nanoparticles and the surface state can be efficiently decreased by sensitization as well as selecting suitable heat treatment. Both the photocurrent response and the charge recombination kinetics in TiO 2 thin films were strongly influenced by trapping/detrapping of surface states. The slow photocurrent response of TiO 2 nanoparticulate thin films upon the illumination was attributed to the trap saturation effects. The semiconductor sensitization made the slow photoresponse disappeared and the steadystate photocurrent value increased drastically, which suggested that the sensitization of TiO 2 thin films with CdS could get a better charge separation and provide a simple alternative to minimize the effect of surface state on the photocurrent response.
文摘TiO 2 nanoparticle film catalysts with different thicknesses were prepared by plasma enhanced chemical vapor deposition(PECVD) method and the surfaces were subsequently treated by TiCl 4 or O 2 plasma. Two kinds of TiO 2 films with different surface properties were obtained. Their surface microstructures and energy levels of surface states were tested by AFM, XRD, SPS. The photocatalytic activities of the catalysts were determined via photodegradation experiments of phenol. The results demonstrated that photocatalytic activities of samples whose surface was treated by O 2 plasma were greater than those treated by TiCl 4 plasma. Moreover, photodegradation ratio of phenol during the first hour catalyzed by 0.17 μm thickness TiO 2 nanoparticle film was greater than other samples. Especially, the difference of photocatalytic activities of TiO 2 nanoparticle films treated by TiCl 4 or O 2 plasma was respectively explained by energy band theory.
文摘Dextran coated magnetic nanocomposites were prepared. A periodate oxidation method was used to further activate the magnetic dextran, forming magnetic polyaldehyde dextran, which could be conjugated to biomolecules, antibodes. The magnetic labeled nano scaled bioconjugates could be well blocked with BSA and exhibit high activity by ELISA and immunochromatographic strip assay.
文摘In the present work, we prepared two kinds of quantum sized ZnO particles whose size were 3 nm(P1) and 5 nm(P2), respectively, and studied their surface properties with surface photovoltage spectroscopy(SPS) and electric field induced surface photovoltage spectroscopy(EFISPS). The photovoltaic response of the two samples showed opposite dependence on external electric field. And when electric field was applied, the thresholds of photovoltaic response of the two samples were all red shifted. The results showed that the surface properties of P1 were different from those of P2, because of their different preparation process. We assigned that basic zinc acetate structure exist on the surface of P1 sample. While for P2 sample prepared by aging P1, that kind of surface structure disappeared, but the particles might be doped with lithium ions in the aging process.
