There is a powerful market-need for superfast disperse dyes in special use, e.g. for automotivefabrics. The photochemical fading reactions of dyes are often very complicated, and no singlphotodegradation pathway can b...There is a powerful market-need for superfast disperse dyes in special use, e.g. for automotivefabrics. The photochemical fading reactions of dyes are often very complicated, and no singlphotodegradation pathway can be involved for all kinds of dyes. To enhance the photostability of the commonly used disperse dyes, a series of tests on the ef-fect of variable stabilizers on the photodegradation rate of nine representative disperse dyes werecarried out both in ethyl acetate solution and on cellulose acetate film. A moderate light sourceemitting above 300 nm was adopted in this study to simulate the photofading under practical appli-cations. The results show that, in solution, 2,2,6,6-tetramethyl-piperidine is the most effectivegeneral stabilizer for all the tested dyes, but on cellulose film, nickel diethyl-dithiocarbamateshows the greatest general protecting effect, and a synergistic effect is observed for special combina-tions of stabilizers.展开更多
An in situ measurement setup is established to investigate the photoinduced degradation effects in a controllable inert gas ambient environment for the two different microstructures of poly（3-hexylthiophene） （P3HT...An in situ measurement setup is established to investigate the photoinduced degradation effects in a controllable inert gas ambient environment for the two different microstructures of poly（3-hexylthiophene） （P3HT） and [6,6]-phenyl-C61- butyricacid methyl ester （PCBM） bulk-heterojunction organic solar cells. The two devices are fabricated with the solvent vapor drying process followed by a thermal annealing （vapor drying device） and only a normal thermal annealing process （control device）, respectively. Their power conversion efficiencies （PCEs） and aging features are compared. Their different degradation behaviors in light absorption are confirmed. In addition, irradiation-induced changes in both nanostructure and surface morphology of the P3HT：PCBM blend films treated with two different fabrication processes are observed through scanning electron microscopy and atomic force microscopy. Aggregated bulbs are observed at the surfaces for control devices after light irradiation for 50 h, while the vapor drying devices exhibit smooth film surfaces, and the corresponding device features are not easy to degrade under the aging measurement. Thus the devices having solvent vapor drying and thermal annealing show better device stabilities than those having only the thermal annealing process.展开更多
Benzotriazole UV stabilizers (BT-UVs) have attracted concems due to their ubiquitous occurrence in the aquatic environment,and their bioaccumulative and toxic properties.However,little is known about their aquatic env...Benzotriazole UV stabilizers (BT-UVs) have attracted concems due to their ubiquitous occurrence in the aquatic environment,and their bioaccumulative and toxic properties.However,little is known about their aquatic environmental degradation behavior.In this study,photodegradation of a representative of BT-UVs,2-(2-hydroxy-5-methylphenyl) benzotriazole (UV-P),was investigated under simulated sunlight irradiation.Results show that UV-P photodegrades slower under neutral conditions (neutral form) than under acidic or alkaline conditions (cationic and anionic forms).Indirect photodegradation is a dominant elimination pathway of UV-P in coastal seawaters.Dissolved organic matter (DOM) from seawaters accelerate the photodegradation rates mainly through excited triplet DOM (3DOM*),and the roles of singlet oxygen and hydroxyl radical are negligible in the matrixes.DOM from seawaters impacted by mariculture exhibits higher steady-state concentration of 3DOM*([3DOM*]) relative to those from pristine seawaters,leading to higher photosensitizing effects on the photodegradation.Halide ions inhibit the DOM-sensitized photodegradation of UV-P by decreasing [3DOM*].Photodegradation half-lives of UV-P are estimated to range from 24.38 to 49.66 hr in field water bodies of the Yellow River estuary.These results are of importance for assessing environmental fate and risk UV-P in coastal water bodies.展开更多
Zn(Ⅱ)-doped graphitic carbon nitride(g-C3N4)with high photodegradation activity was prepared by one facile step.The morphology and structure of the prepared Zn(Ⅱ)-doped g-C3N4 were investigated,and the results showe...Zn(Ⅱ)-doped graphitic carbon nitride(g-C3N4)with high photodegradation activity was prepared by one facile step.The morphology and structure of the prepared Zn(Ⅱ)-doped g-C3N4 were investigated,and the results showed that Zn(Ⅱ)could self-disperse during the pyrolysis process and Zn–N bond was formed between g-C3N4 and Zn.The dope of Zn(Ⅱ)influenced the structure of g-C3N4.The performance of photocatalytic activity of Zn(Ⅱ)-doped g-C3 N4 series indicated that the doped g-C3N4 with a small quantity of Zn(0.10 wt%)exhibits the best photocatalytic performance.The photodegradation activity for methyl orange was 2 times higher than that of pure g-C3N4.However,the photocatalytic activity decreased with the further increased content of Zn,which may be attributed to the structure change of g-C3N4 and the interaction of Zn–N bond between Zn and g-C3N4.Moreover,Zn(Ⅱ)-doped g-C3N4 showed good recycling photocatalytic stability.展开更多
Nanoflower-like ZnO-C_(3)N_(4) thin film with a porous net structure was successfully synthesized by a simple chemical corrosion method.The prepared ZnOC_(3)N_(4) thin films presented remarkable photocatalytic activit...Nanoflower-like ZnO-C_(3)N_(4) thin film with a porous net structure was successfully synthesized by a simple chemical corrosion method.The prepared ZnOC_(3)N_(4) thin films presented remarkable photocatalytic activities for the degradation of methyl orange under visible light irradiation,and more than 90%methyl orange was removed from water by ZnO-C_(3)N_(4) composite.Meanwhile,the ZnO-C_(3)N_(4) composite presented an enhanced photocatalytic stability.The loading content of C_(3)N_(4) had a great effect on the photocatalytic performance.Moreover,the photocatalytic activities were higher in acidic media than those in alkaline conditions.The adsorption of methyl orange was enhanced,and the recombination of photogenerated electrons and holes was suppressed with a suitable content of C_(3)N_(4).However,too much loading content of C_(3)N_(4) resulted in a poor dispersion of C_(3)N_(4) as the aggregated C_(3)N_(4) can behave as recombination centers.In addition,the prepared ZnO-C_(3)N_(4) thin film can be used for the water splitting in water-methanol system under simulated solar light irradiation.展开更多
文摘There is a powerful market-need for superfast disperse dyes in special use, e.g. for automotivefabrics. The photochemical fading reactions of dyes are often very complicated, and no singlphotodegradation pathway can be involved for all kinds of dyes. To enhance the photostability of the commonly used disperse dyes, a series of tests on the ef-fect of variable stabilizers on the photodegradation rate of nine representative disperse dyes werecarried out both in ethyl acetate solution and on cellulose acetate film. A moderate light sourceemitting above 300 nm was adopted in this study to simulate the photofading under practical appli-cations. The results show that, in solution, 2,2,6,6-tetramethyl-piperidine is the most effectivegeneral stabilizer for all the tested dyes, but on cellulose film, nickel diethyl-dithiocarbamateshows the greatest general protecting effect, and a synergistic effect is observed for special combina-tions of stabilizers.
基金Project supported by the National Basic Research Program of China(Grant No.2011CB932801)the New Teachers’Fund for Doctor Stations,Ministry of Education,China(Grant No.20112216120008)
文摘An in situ measurement setup is established to investigate the photoinduced degradation effects in a controllable inert gas ambient environment for the two different microstructures of poly（3-hexylthiophene） （P3HT） and [6,6]-phenyl-C61- butyricacid methyl ester （PCBM） bulk-heterojunction organic solar cells. The two devices are fabricated with the solvent vapor drying process followed by a thermal annealing （vapor drying device） and only a normal thermal annealing process （control device）, respectively. Their power conversion efficiencies （PCEs） and aging features are compared. Their different degradation behaviors in light absorption are confirmed. In addition, irradiation-induced changes in both nanostructure and surface morphology of the P3HT：PCBM blend films treated with two different fabrication processes are observed through scanning electron microscopy and atomic force microscopy. Aggregated bulbs are observed at the surfaces for control devices after light irradiation for 50 h, while the vapor drying devices exhibit smooth film surfaces, and the corresponding device features are not easy to degrade under the aging measurement. Thus the devices having solvent vapor drying and thermal annealing show better device stabilities than those having only the thermal annealing process.
基金supported by the National Key R&D Program of China(No.2018YFC1801604)the National Natural Science Foundation of China(No.21661142001)
文摘Benzotriazole UV stabilizers (BT-UVs) have attracted concems due to their ubiquitous occurrence in the aquatic environment,and their bioaccumulative and toxic properties.However,little is known about their aquatic environmental degradation behavior.In this study,photodegradation of a representative of BT-UVs,2-(2-hydroxy-5-methylphenyl) benzotriazole (UV-P),was investigated under simulated sunlight irradiation.Results show that UV-P photodegrades slower under neutral conditions (neutral form) than under acidic or alkaline conditions (cationic and anionic forms).Indirect photodegradation is a dominant elimination pathway of UV-P in coastal seawaters.Dissolved organic matter (DOM) from seawaters accelerate the photodegradation rates mainly through excited triplet DOM (3DOM*),and the roles of singlet oxygen and hydroxyl radical are negligible in the matrixes.DOM from seawaters impacted by mariculture exhibits higher steady-state concentration of 3DOM*([3DOM*]) relative to those from pristine seawaters,leading to higher photosensitizing effects on the photodegradation.Halide ions inhibit the DOM-sensitized photodegradation of UV-P by decreasing [3DOM*].Photodegradation half-lives of UV-P are estimated to range from 24.38 to 49.66 hr in field water bodies of the Yellow River estuary.These results are of importance for assessing environmental fate and risk UV-P in coastal water bodies.
基金financially supported by the National Natural Science Foundation of China(No.51574071)
文摘Zn(Ⅱ)-doped graphitic carbon nitride(g-C3N4)with high photodegradation activity was prepared by one facile step.The morphology and structure of the prepared Zn(Ⅱ)-doped g-C3N4 were investigated,and the results showed that Zn(Ⅱ)could self-disperse during the pyrolysis process and Zn–N bond was formed between g-C3N4 and Zn.The dope of Zn(Ⅱ)influenced the structure of g-C3N4.The performance of photocatalytic activity of Zn(Ⅱ)-doped g-C3 N4 series indicated that the doped g-C3N4 with a small quantity of Zn(0.10 wt%)exhibits the best photocatalytic performance.The photodegradation activity for methyl orange was 2 times higher than that of pure g-C3N4.However,the photocatalytic activity decreased with the further increased content of Zn,which may be attributed to the structure change of g-C3N4 and the interaction of Zn–N bond between Zn and g-C3N4.Moreover,Zn(Ⅱ)-doped g-C3N4 showed good recycling photocatalytic stability.
基金financially supported by the National Natural Science Foundation of China(No.51574071)。
文摘Nanoflower-like ZnO-C_(3)N_(4) thin film with a porous net structure was successfully synthesized by a simple chemical corrosion method.The prepared ZnOC_(3)N_(4) thin films presented remarkable photocatalytic activities for the degradation of methyl orange under visible light irradiation,and more than 90%methyl orange was removed from water by ZnO-C_(3)N_(4) composite.Meanwhile,the ZnO-C_(3)N_(4) composite presented an enhanced photocatalytic stability.The loading content of C_(3)N_(4) had a great effect on the photocatalytic performance.Moreover,the photocatalytic activities were higher in acidic media than those in alkaline conditions.The adsorption of methyl orange was enhanced,and the recombination of photogenerated electrons and holes was suppressed with a suitable content of C_(3)N_(4).However,too much loading content of C_(3)N_(4) resulted in a poor dispersion of C_(3)N_(4) as the aggregated C_(3)N_(4) can behave as recombination centers.In addition,the prepared ZnO-C_(3)N_(4) thin film can be used for the water splitting in water-methanol system under simulated solar light irradiation.
