The modification of the traditional interior wall paint was carried out by means of adding nano-TiO2 as a functional pigment. By regulating the dosage of dispersant, the nano-particles can be dispersed in paint homoge...The modification of the traditional interior wall paint was carried out by means of adding nano-TiO2 as a functional pigment. By regulating the dosage of dispersant, the nano-particles can be dispersed in paint homogeneously. With two aspects of experiments： dosage of nano-TiO2 and pigment volume concentration （PVC）, the paint formulation can be optimized and its properties~ such as hardness, scrub resistance, storage stability, contrast ratio and gloss can be improved. Finally an interior wall paint with high performance and air purification was prepared. Its character of formaldehyde degradation would be discussed in the next article.展开更多
Powder quartz(PQ)/nano-TiO2composite was prepared by a mechanochemical method. Based on as-prepared PQ/nano-TiO2composite, we prepared interior paints and investigated the degradation efficiency of formaldehyde(DEF). ...Powder quartz(PQ)/nano-TiO2composite was prepared by a mechanochemical method. Based on as-prepared PQ/nano-TiO2composite, we prepared interior paints and investigated the degradation efficiency of formaldehyde(DEF). Scanning electron microscopy showed that nano-TiO2got well dispersed by the adding of PQ. Thermogravimetric analysis indicated that the mass ratio of 4:1 was a relatively good proportion for the most production of PQ/nano-TiO2composite. Fourier transform-infrared spectrometry showed that the peak position of Ti-O-Si bond varied with the milling time. At the early stage, no characteristic peak of Ti-O-Si bond was observed, while at the later stage, new peaks at 902 cm-1and 937 cm-1appeared. Meanwhile, PQ/nano-TiO2composite-based interior paint exhibited significant DEF of 96.3% compared to that consisting of sole nanoTiO2of 92.0% under visible light illumination. As an abundant mineral resource, PQ would make interior paints with HCHO purifying effect much more efficient and cheaper.展开更多
The mechanism for tourmaline powder improving the photocatalysis effect of nano-TiO2 was studied by electron-spin resonance (ESR). It is found that the intensity of the signal of hydroxyl free radical produced by the ...The mechanism for tourmaline powder improving the photocatalysis effect of nano-TiO2 was studied by electron-spin resonance (ESR). It is found that the intensity of the signal of hydroxyl free radical produced by the mixture of the tourmaline and nano-TiO2 through 355nm wavelength ultraviolet radiating is increased. Under natural light, the mixture of nano TiO2 and tourmaline powder in a certain weight ratio can improve the effect of decomposing methyl orange that proved that the ESR result was right. The tourmaline particle could promote the photocatalysis of nano-TiO2. This result may be due to the surface electric field of the tourmaline, which can absorb the particle of nano-TiO2 and make the electron inspired by photon transfer from the inner of nano-TiO2 particle to its surface, and even make the electron transfer into tourmaline particle.展开更多
Cell surface of aquatic organisms constitutes a primary site for the interaction and a barrier for the nano-TiO2 biological effects.In the present study,the biological effects of nano-TiO2 on a unicellular green algae...Cell surface of aquatic organisms constitutes a primary site for the interaction and a barrier for the nano-TiO2 biological effects.In the present study,the biological effects of nano-TiO2 on a unicellular green algae Chlamydomonas reinhardtii were studied by observing the changes of the cell surface morphology and functional groups under UV or natural light.By SEM,the cell surface morphology of C.reinhardtii was changed under UV light,nano-TiO2 with UV light or natural light,which indicated that photocatalysis damaged cell surface.It was also observed that cell surface was surrounded by TiO2 nanoparticles.The ATR-FTIR spectra showed that the peaks of functional groups such as C-N,-C=O,-C-O-C and P=O,which were the important components of cell wall and membrane,were all depressed by the photocatalysis of nano-TiO2 under UV light or natural light.The photocatalysis of nano-TiO2 promoted peroxidation of functional groups on the surface of C.reinhardtii cells,which led to the damages of cell wall and membrane.展开更多
Mn:ZnSe/ZnS/L-Cys core-shell quantum dots(QDs)sensitized La-doped nano-TiO2 thin film(QDSTF)was prepared.X-ray photoelectron spectroscopy(XPS),nanosecond transient photovoltaic(TPV),and steady state surface photovolta...Mn:ZnSe/ZnS/L-Cys core-shell quantum dots(QDs)sensitized La-doped nano-TiO2 thin film(QDSTF)was prepared.X-ray photoelectron spectroscopy(XPS),nanosecond transient photovoltaic(TPV),and steady state surface photovoltaic(SPV)technologies were used for probing the photoelectron behaviors in the Mn-doped QDSTF.The results revealed that the Mn-doped QDSTF had a p-type TPV characteristic.The bottom of the conduction band of the QDs as a sensitizer was just 0.86 eV above that of the La-doped nano-TiO2 thin film,while the acceptor level of the doped Mn2+ions was located at about 0.39 eV below and near the bottom of the conduction band of the QDs.The intensity of the SPV response of the Mn-doped QDSTF at a specific wavelength was ~2.1 times higher than that of the undoped QDSTF.The region of the SPV response of the Mn-doped QDSTF was extended by 191 nm to almost the whole visible region as compared with the undoped QDSTF one.And the region of the TPV response of the Mn-doped QDSTF was also obviously wider than that of the undoped QDSTF.These PV characteristics of the Mn-doped QDSTF may be due to the prolonged lifetime and extended diffusion length of photogenerated free charge carriers injected into the sensitized La-doped nano-TiO2 thin film.展开更多
Nano-TiO2 photocatalytic oxidation was used to perform the advanced treatment of biologically treated chemical comprehensive wastewater. The effects of reaction time,nano-TiO2 dosage and initial p H of the wastewater ...Nano-TiO2 photocatalytic oxidation was used to perform the advanced treatment of biologically treated chemical comprehensive wastewater. The effects of reaction time,nano-TiO2 dosage and initial p H of the wastewater on the removal rate of COD were tested. The GC/MS and EEM techniques were used to qualitatively analyze organic compounds in the wastewater before and after treatment. The result showed that after the biologically treated chemical comprehensive wastewater was treated by nano-TiO2 photocatalytic oxidation under the conditions of reaction time 3 h,nano-TiO2 dosage 8 g/L,and pH 8. 0,the effluent COD was 61. 9 mg/L and its removal rate was 63. 8%. Additionally,the species of organic pollutants reduced from 12 to 6. Meanwhile,the content of humic-like and fulvic-like substances dropped dramatically.展开更多
Based on the sol-gel technique using butyl titanate as oxide precursor, the regenerated SF （silk fibroin）/nano-TiO2 composite films were synthesized. Different amounts of butyl titanate to SF were used to verify thi...Based on the sol-gel technique using butyl titanate as oxide precursor, the regenerated SF （silk fibroin）/nano-TiO2 composite films were synthesized. Different amounts of butyl titanate to SF were used to verify this effect on the characteristics of the formed materials. Samples were characterized by thermogravimetric analysis, X-ray diffractometry, UV, AFM and FT-IR spectroscopy. The experimental results reveal that, compared to the pure silk fibroin films, the mechanical strength of these regenerated SF/nano-TiO2 composite films were increased and the dissolubility in water of SF/nano-TiO2 composite films in aqueous solution were decreased. The diameter of nano-TiO2 particle films was about 80nm through UV and AFM. The nano-TiO2 particles were well dispersed in the regenerated silk fibroin. It was found that the crystal structures of the composite films were transited from typical Silk I to typical Silk H by the XRD and FTIR. Furthermore, the crystallinity of the composite films was obviously improved. Through the TGA, it was demonstrated that the heat transition temperature of composite films was also enhanced.展开更多
基金Project supported by the Foundation of National Key Technologies Research and Development Program-Shanghai World Expo Special Project (Grant No.04DZ05803)
文摘The modification of the traditional interior wall paint was carried out by means of adding nano-TiO2 as a functional pigment. By regulating the dosage of dispersant, the nano-particles can be dispersed in paint homogeneously. With two aspects of experiments： dosage of nano-TiO2 and pigment volume concentration （PVC）, the paint formulation can be optimized and its properties~ such as hardness, scrub resistance, storage stability, contrast ratio and gloss can be improved. Finally an interior wall paint with high performance and air purification was prepared. Its character of formaldehyde degradation would be discussed in the next article.
基金Funded by the National Natural Science Foundation of China(No.41130746)
文摘Powder quartz(PQ)/nano-TiO2composite was prepared by a mechanochemical method. Based on as-prepared PQ/nano-TiO2composite, we prepared interior paints and investigated the degradation efficiency of formaldehyde(DEF). Scanning electron microscopy showed that nano-TiO2got well dispersed by the adding of PQ. Thermogravimetric analysis indicated that the mass ratio of 4:1 was a relatively good proportion for the most production of PQ/nano-TiO2composite. Fourier transform-infrared spectrometry showed that the peak position of Ti-O-Si bond varied with the milling time. At the early stage, no characteristic peak of Ti-O-Si bond was observed, while at the later stage, new peaks at 902 cm-1and 937 cm-1appeared. Meanwhile, PQ/nano-TiO2composite-based interior paint exhibited significant DEF of 96.3% compared to that consisting of sole nanoTiO2of 92.0% under visible light illumination. As an abundant mineral resource, PQ would make interior paints with HCHO purifying effect much more efficient and cheaper.
基金The National Nature Science Foundation of China (50272062) and Beijing City Science Foundation of China(2042021)
文摘The mechanism for tourmaline powder improving the photocatalysis effect of nano-TiO2 was studied by electron-spin resonance (ESR). It is found that the intensity of the signal of hydroxyl free radical produced by the mixture of the tourmaline and nano-TiO2 through 355nm wavelength ultraviolet radiating is increased. Under natural light, the mixture of nano TiO2 and tourmaline powder in a certain weight ratio can improve the effect of decomposing methyl orange that proved that the ESR result was right. The tourmaline particle could promote the photocatalysis of nano-TiO2. This result may be due to the surface electric field of the tourmaline, which can absorb the particle of nano-TiO2 and make the electron inspired by photon transfer from the inner of nano-TiO2 particle to its surface, and even make the electron transfer into tourmaline particle.
基金Funded by the National Natural Science Foundation of China(No.51579159)
文摘Cell surface of aquatic organisms constitutes a primary site for the interaction and a barrier for the nano-TiO2 biological effects.In the present study,the biological effects of nano-TiO2 on a unicellular green algae Chlamydomonas reinhardtii were studied by observing the changes of the cell surface morphology and functional groups under UV or natural light.By SEM,the cell surface morphology of C.reinhardtii was changed under UV light,nano-TiO2 with UV light or natural light,which indicated that photocatalysis damaged cell surface.It was also observed that cell surface was surrounded by TiO2 nanoparticles.The ATR-FTIR spectra showed that the peaks of functional groups such as C-N,-C=O,-C-O-C and P=O,which were the important components of cell wall and membrane,were all depressed by the photocatalysis of nano-TiO2 under UV light or natural light.The photocatalysis of nano-TiO2 promoted peroxidation of functional groups on the surface of C.reinhardtii cells,which led to the damages of cell wall and membrane.
基金Project supported by the Natural Science Foundation of Hebei Province,China(Grant No.E2017203029)。
文摘Mn:ZnSe/ZnS/L-Cys core-shell quantum dots(QDs)sensitized La-doped nano-TiO2 thin film(QDSTF)was prepared.X-ray photoelectron spectroscopy(XPS),nanosecond transient photovoltaic(TPV),and steady state surface photovoltaic(SPV)technologies were used for probing the photoelectron behaviors in the Mn-doped QDSTF.The results revealed that the Mn-doped QDSTF had a p-type TPV characteristic.The bottom of the conduction band of the QDs as a sensitizer was just 0.86 eV above that of the La-doped nano-TiO2 thin film,while the acceptor level of the doped Mn2+ions was located at about 0.39 eV below and near the bottom of the conduction band of the QDs.The intensity of the SPV response of the Mn-doped QDSTF at a specific wavelength was ~2.1 times higher than that of the undoped QDSTF.The region of the SPV response of the Mn-doped QDSTF was extended by 191 nm to almost the whole visible region as compared with the undoped QDSTF one.And the region of the TPV response of the Mn-doped QDSTF was also obviously wider than that of the undoped QDSTF.These PV characteristics of the Mn-doped QDSTF may be due to the prolonged lifetime and extended diffusion length of photogenerated free charge carriers injected into the sensitized La-doped nano-TiO2 thin film.
文摘Nano-TiO2 photocatalytic oxidation was used to perform the advanced treatment of biologically treated chemical comprehensive wastewater. The effects of reaction time,nano-TiO2 dosage and initial p H of the wastewater on the removal rate of COD were tested. The GC/MS and EEM techniques were used to qualitatively analyze organic compounds in the wastewater before and after treatment. The result showed that after the biologically treated chemical comprehensive wastewater was treated by nano-TiO2 photocatalytic oxidation under the conditions of reaction time 3 h,nano-TiO2 dosage 8 g/L,and pH 8. 0,the effluent COD was 61. 9 mg/L and its removal rate was 63. 8%. Additionally,the species of organic pollutants reduced from 12 to 6. Meanwhile,the content of humic-like and fulvic-like substances dropped dramatically.
基金National Natural Science Foundation of China（Grant No. 50573068） and Zhejiang Natural Science Foundation of China （Grant No. Y405459）.
文摘Based on the sol-gel technique using butyl titanate as oxide precursor, the regenerated SF （silk fibroin）/nano-TiO2 composite films were synthesized. Different amounts of butyl titanate to SF were used to verify this effect on the characteristics of the formed materials. Samples were characterized by thermogravimetric analysis, X-ray diffractometry, UV, AFM and FT-IR spectroscopy. The experimental results reveal that, compared to the pure silk fibroin films, the mechanical strength of these regenerated SF/nano-TiO2 composite films were increased and the dissolubility in water of SF/nano-TiO2 composite films in aqueous solution were decreased. The diameter of nano-TiO2 particle films was about 80nm through UV and AFM. The nano-TiO2 particles were well dispersed in the regenerated silk fibroin. It was found that the crystal structures of the composite films were transited from typical Silk I to typical Silk H by the XRD and FTIR. Furthermore, the crystallinity of the composite films was obviously improved. Through the TGA, it was demonstrated that the heat transition temperature of composite films was also enhanced.
