The ultraviolet(UV)light stability of silicon heterojunction(SHJ)solar cells should be addressed before large-scale production and applications.Introducing downshifting(DS)nanophosphors on top of solar cells that can ...The ultraviolet(UV)light stability of silicon heterojunction(SHJ)solar cells should be addressed before large-scale production and applications.Introducing downshifting(DS)nanophosphors on top of solar cells that can convert UV light to visible light may reduce UV-induced degradation(UVID)without sacrificing the power conversion efficiency(PCE).Herein,a novel composite DS nanomaterial composed of YVO_(4):Eu^(3+),Bi^(3+)nanoparticles(NPs)and AgNPs was synthesized and introduced onto the incident light side of industrial SHJ solar cells to achieve UV shielding.The YVO_(4):Eu^(3+),Bi^(3+)NPs and Ag NPs were synthesized via a sol-gel method and a wet chemical reduction method,respectively.Then,a composite structure of the YVO_(4):Eu^(3+),Bi^(3+)NPs decorated with Ag NPs was synthesized by an ultrasonic method.The emission intensities of the YVO_(4):Eu^(3+),Bi^(3+)nanophosphors were significantly enhanced upon decoration with an appropriate amount of~20 nm Ag NPs due to the localized surface plasmon resonance(LSPR)effect.Upon the introduction of LSPR-enhanced downshifting,the SHJ solar cells exhibited an~0.54%relative decrease in PCE degradation under UV irradiation with a cumulative dose of 45 k W h compared to their counterparts,suggesting excellent potential for application in UV-light stability enhancement of solar cells or modules.展开更多
We investigated the effects of Si-layer-thickness ratios on ultraviolet (UV) peak intensities of Si/ SiO2 multilayered films produced by alternately stacking several-nanometer-thick Si and SiO2 layers using radio-freq...We investigated the effects of Si-layer-thickness ratios on ultraviolet (UV) peak intensities of Si/ SiO2 multilayered films produced by alternately stacking several-nanometer-thick Si and SiO2 layers using radio-frequency sputtering for the first time. The Si-layer-thickness ratio of the Si/SiO2 film is a very important parameter for enhancing the peak intensity because the ratio is concerned with the size of Si nanocrystals in the film, which might affect the intensity of the UV light emission from the film. We prepared seven samples with various estimated Si-layer-thickness ratios, and measured the photoluminescence spectra of the samples after annealing at 1150°C, 1200°C, or 1250°C for 25 min. From our experiments, we estimate that the proper Si-layer-thickness ratio to obtain the strongest UV peaks from the Si/SiO2 multilayered films is around 0.29. Such a UV-lightemitting thin film is expected to be used in future higher-density optical-disk systems.展开更多
Syntheses of zince oxide(ZnO) nanoparticles by direct precipitation and surface modification with oleic acid were reported. ZnO nanoparticles were characterized via X-ray diffractometry(XRD), transmission electron mic...Syntheses of zince oxide(ZnO) nanoparticles by direct precipitation and surface modification with oleic acid were reported. ZnO nanoparticles were characterized via X-ray diffractometry(XRD), transmission electron microscopy(TEM), infrared spectroscopy(IR) and UV-Vis spectroscopy. The prepared ZnO nanoparticles were nearly spherical and highly crystalline with an average size of 29 nm. In addition, high UV-light absorption properties of oleic acid surface modified ZnO nanoparticles were successfully obtained for a dispersion of ZnO nanoparticles in ethanol.展开更多
After comparison of Trichoderma population density and test of colonization ability in rhizospheres were conducted. Auxotrophic mutants of T. harzianum tolerant to carbendazim and UV-light were obtained by UV-light mu...After comparison of Trichoderma population density and test of colonization ability in rhizospheres were conducted. Auxotrophic mutants of T. harzianum tolerant to carbendazim and UV-light were obtained by UV-light mutagenesis and carbendazim stress on PDA medium and a basis medium with hot pepper root exudation by adding the fungicide. The results showed: all four different isolates of Trichoderma had certain colonization ability in rhizosphere with the characteristic of growing as roots and distributing many more around root tips. The ability, however, was different for the 4 isolates, showing the wild isolates colonized weakly in rhizosphere. Around 5% spores alive and mutants could be obtained after the isolates were irradiated under a 20W UV-light at 25 cm distance for 5 min. The mutants tolerant to carbendazim were screened out by adding the fungicide into PDA medium, which increased resistance to the fungicide 100 times higher than their original isolates and showed auxotrophic. Three mutants,G7n,G20n and G5n, grew very well on PDA and a basic medium with hot pepper root exudation. Therefore, these mutants could be used as the isolates with good colonization ability for further research.展开更多
The conventional methods of using surfactants to synthesize noble metal nanoparticles usually introduce residues on the surface,which inevitably decreases nanoparticles’ surface enhanced Raman scattering(SERS) perfor...The conventional methods of using surfactants to synthesize noble metal nanoparticles usually introduce residues on the surface,which inevitably decreases nanoparticles’ surface enhanced Raman scattering(SERS) performance.Herein,we propose a surfactant-free and feasible approach of preparing cerium hexaboride-Ag nano-trees hybrids(CeB_(6)@Ag nano-trees) as the SERS substrate.First,the CeB_(6)was synthesized by a one-pot ionothermal method.Secondly,the CeB_(6)powder and silver nitrate were dispersed in an aqueous solution.Thereafter,the Ag+was reduced by the UV-light assisted photoreaction and deposited on the surface of the CeB_(6).The SERS performance of the CeB_(6)@Ag nano-trees was evaluated by using the Rhodamine 6 G as the Raman reporter.It shows that CeB_(6)@Ag nano-trees exhibit good SERS sensitivity with the enhancement factor of 2.45 × 10^(7) and detection limit of 10^(-10) mol/L.Moreover,uniformity evaluation of the SERS signal intensity on the substrate also shows that relatively good relative standard deviation values of 12.6%(Raman peak@612 cm^(-1)) and 14.1%(Raman peak@1652 cm^(-1))can be achieved.Finally,finite element simulation evidences that excellent SERS performance of the CeB_(6)@Ag nano-trees is produced by the strong coupled localized surface plasmon resonance generated under the Raman laser irradiation.展开更多
Ultralong organic phosphorescence(UOP)materials have roused considerable attention in the field of photonics and optoelectronics owing to the feature of long-lived emission lifetimes.However,to develop UOP materials w...Ultralong organic phosphorescence(UOP)materials have roused considerable attention in the field of photonics and optoelectronics owing to the feature of long-lived emission lifetimes.However,to develop UOP materials with color-tunability is still a formidable challenge.Here,we report a class of UOP materials containing carbonyl,amino or amide groups,exhibiting colortunable persistent luminescence ranging from blue(458 nm)to yellow-green(508 nm)under different UV wavelength excitation.Taken theoretical and experimental results together,we conclude that the excitation dependent color-tunable UOP emission is ascribed to multiple emission centers from single molecular and aggregated states in crystal.Given color-tunable UOP feature,these materials are used to successfully realize visual UV-light detection.This finding not only provides a strategy to design new organic phosphorescent molecules with colorful emission,but also extends the scope of the applications of purely organic phosphorescent materials.展开更多
Recently,exploiting a novel supramolecular fabrication pathway have drawn great attention.To this endeavor,we firstly designed and reported an original light-activated platform based on the internal-driven forces of m...Recently,exploiting a novel supramolecular fabrication pathway have drawn great attention.To this endeavor,we firstly designed and reported an original light-activated platform based on the internal-driven forces of macrocyclic host by hiring the pillar[5]arene as the host molecule(H)and phenazine derivatives acting as an energetic guest molecule(G).Surprisingly,after adding the H solution into G system,the intensive fluorescence emission of the G molecule rapidly decreased under the irradiation of the UV-light(254 nm)until absolutely quenching.Delightfully,different from the traditional supramolecular host-guest interaction,the fluorescent emission of G molecule could be recovered after irradiating under the nature light.In view of this interesting observations,the interaction mechanism was carefully investigated by a series of characterizations.Those results suggested that the G molecule was easily threaded into the macrocyclic cavity(H)under the internal-driven forces induced by the UV-light irradiation,forming a 1:1 host-guest complex.Moreover,taking advantage of this especial feature,the light-activated platform of host-guest complex was further applied for ink-free light-driven printing materials,exhibiting great potential in the real application.展开更多
The effect of nanometer anatase TiO2 was investigated on the photocatalytic degradation of phenanthrene on soil surfaces under a variety of conditions.After being spiked with phenanthrene,soil samples loaded with diff...The effect of nanometer anatase TiO2 was investigated on the photocatalytic degradation of phenanthrene on soil surfaces under a variety of conditions.After being spiked with phenanthrene,soil samples loaded with different amounts of TiO2(0wt.%,1wt.%,2wt.%,3wt.%,and 4 wt.%) were exposed to UV-light irradiation for 25 hr.The results indicated that the photocatalytic degradation of phenanthrene followed the pseudo first-order kinetics.TiO2 significantly accelerated the degradation of phenanthrene with the half-life reduced from 45.90 to 31.36hr for TiO2 loading of 0wt.% and 4wt.%,respectively.In addition,the effects of H2O2,light intensity and humic acid on the degradation of phenanthrene were investigated.The degradation of phenanthrene increased with the concentration of H2O2,light intensity and the concentration of humic acids.It has been demonstrated that the photocatalytic method in the presence of nanometer anatase TiO2 was a very promising technology for the treatments of soil polluted with organic substances in the future.展开更多
Y and Eu co-doped nano-TiO2 photocatalysts were successfully prepared via a sol-gel method and characterized by X-ray diffraction(XRD), transmission electron microscopy(TEM), ultraviolet-visible spectrophotometry(UV-v...Y and Eu co-doped nano-TiO2 photocatalysts were successfully prepared via a sol-gel method and characterized by X-ray diffraction(XRD), transmission electron microscopy(TEM), ultraviolet-visible spectrophotometry(UV-vis), photoluminescence(PL) and Fourier transform infrared(FT-IR) spectra. Experimental results indicated that Y and Eu doping inhibited the growth of crystalline size and the transformation from anatase to rutile phase and had the function of reducing particle reunion. At the same time, co-doping could also enhance the absorption in visible region and then narrowed the band gap. The photocatalytic activities of the samples were evaluated by the degradation of methylene blue(MB) under ultraviolet(UV) light irradiation, which showed much enhanced photocatalytic activities over un-doped TiO2. The degradation rate of 1.5% Y/Eu-TiO2 of methylene blue was 86%, which was about 5 times of that of un-doped TiO2, and the possible reasons for the improvement of photocatalytic activities were analyzed. In this experiment, the dopant amount of rare earth was 1.5% and the ratio of Y:Eu was 2:3 for the maximum photocatalytic degradation, and the sample calcined at 500 oC showed the best reactivity. For the best samples above, the removal rate of phenol under visble light was 53% whthin 2 h.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.52202276 and 51821002)the China Postdoctoral Science Foundation (Grant No.2022M712300)+1 种基金the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (Grant No.22KJB480010)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)。
文摘The ultraviolet(UV)light stability of silicon heterojunction(SHJ)solar cells should be addressed before large-scale production and applications.Introducing downshifting(DS)nanophosphors on top of solar cells that can convert UV light to visible light may reduce UV-induced degradation(UVID)without sacrificing the power conversion efficiency(PCE).Herein,a novel composite DS nanomaterial composed of YVO_(4):Eu^(3+),Bi^(3+)nanoparticles(NPs)and AgNPs was synthesized and introduced onto the incident light side of industrial SHJ solar cells to achieve UV shielding.The YVO_(4):Eu^(3+),Bi^(3+)NPs and Ag NPs were synthesized via a sol-gel method and a wet chemical reduction method,respectively.Then,a composite structure of the YVO_(4):Eu^(3+),Bi^(3+)NPs decorated with Ag NPs was synthesized by an ultrasonic method.The emission intensities of the YVO_(4):Eu^(3+),Bi^(3+)nanophosphors were significantly enhanced upon decoration with an appropriate amount of~20 nm Ag NPs due to the localized surface plasmon resonance(LSPR)effect.Upon the introduction of LSPR-enhanced downshifting,the SHJ solar cells exhibited an~0.54%relative decrease in PCE degradation under UV irradiation with a cumulative dose of 45 k W h compared to their counterparts,suggesting excellent potential for application in UV-light stability enhancement of solar cells or modules.
文摘We investigated the effects of Si-layer-thickness ratios on ultraviolet (UV) peak intensities of Si/ SiO2 multilayered films produced by alternately stacking several-nanometer-thick Si and SiO2 layers using radio-frequency sputtering for the first time. The Si-layer-thickness ratio of the Si/SiO2 film is a very important parameter for enhancing the peak intensity because the ratio is concerned with the size of Si nanocrystals in the film, which might affect the intensity of the UV light emission from the film. We prepared seven samples with various estimated Si-layer-thickness ratios, and measured the photoluminescence spectra of the samples after annealing at 1150°C, 1200°C, or 1250°C for 25 min. From our experiments, we estimate that the proper Si-layer-thickness ratio to obtain the strongest UV peaks from the Si/SiO2 multilayered films is around 0.29. Such a UV-lightemitting thin film is expected to be used in future higher-density optical-disk systems.
基金Supported by the Key Project of the National Eleventh Five-Year Research Programe of China(No.2008BAE66B00)
文摘Syntheses of zince oxide(ZnO) nanoparticles by direct precipitation and surface modification with oleic acid were reported. ZnO nanoparticles were characterized via X-ray diffractometry(XRD), transmission electron microscopy(TEM), infrared spectroscopy(IR) and UV-Vis spectroscopy. The prepared ZnO nanoparticles were nearly spherical and highly crystalline with an average size of 29 nm. In addition, high UV-light absorption properties of oleic acid surface modified ZnO nanoparticles were successfully obtained for a dispersion of ZnO nanoparticles in ethanol.
文摘After comparison of Trichoderma population density and test of colonization ability in rhizospheres were conducted. Auxotrophic mutants of T. harzianum tolerant to carbendazim and UV-light were obtained by UV-light mutagenesis and carbendazim stress on PDA medium and a basis medium with hot pepper root exudation by adding the fungicide. The results showed: all four different isolates of Trichoderma had certain colonization ability in rhizosphere with the characteristic of growing as roots and distributing many more around root tips. The ability, however, was different for the 4 isolates, showing the wild isolates colonized weakly in rhizosphere. Around 5% spores alive and mutants could be obtained after the isolates were irradiated under a 20W UV-light at 25 cm distance for 5 min. The mutants tolerant to carbendazim were screened out by adding the fungicide into PDA medium, which increased resistance to the fungicide 100 times higher than their original isolates and showed auxotrophic. Three mutants,G7n,G20n and G5n, grew very well on PDA and a basic medium with hot pepper root exudation. Therefore, these mutants could be used as the isolates with good colonization ability for further research.
基金Project supported by National Natural Science Foundation of China (62105172)the Fundamental Research Funds for the Provincial Universities of Zhejiang (ZX2022000300)。
文摘The conventional methods of using surfactants to synthesize noble metal nanoparticles usually introduce residues on the surface,which inevitably decreases nanoparticles’ surface enhanced Raman scattering(SERS) performance.Herein,we propose a surfactant-free and feasible approach of preparing cerium hexaboride-Ag nano-trees hybrids(CeB_(6)@Ag nano-trees) as the SERS substrate.First,the CeB_(6)was synthesized by a one-pot ionothermal method.Secondly,the CeB_(6)powder and silver nitrate were dispersed in an aqueous solution.Thereafter,the Ag+was reduced by the UV-light assisted photoreaction and deposited on the surface of the CeB_(6).The SERS performance of the CeB_(6)@Ag nano-trees was evaluated by using the Rhodamine 6 G as the Raman reporter.It shows that CeB_(6)@Ag nano-trees exhibit good SERS sensitivity with the enhancement factor of 2.45 × 10^(7) and detection limit of 10^(-10) mol/L.Moreover,uniformity evaluation of the SERS signal intensity on the substrate also shows that relatively good relative standard deviation values of 12.6%(Raman peak@612 cm^(-1)) and 14.1%(Raman peak@1652 cm^(-1))can be achieved.Finally,finite element simulation evidences that excellent SERS performance of the CeB_(6)@Ag nano-trees is produced by the strong coupled localized surface plasmon resonance generated under the Raman laser irradiation.
基金supported by the National Natural Science Foundation of China(21875104,21975120,21973043,91833304,51673095)the Natural Science Fund for Distinguished Young Scholars of Jiangsu Province(BK20180037)the Fundamental Research Funds for the Central Universities。
文摘Ultralong organic phosphorescence(UOP)materials have roused considerable attention in the field of photonics and optoelectronics owing to the feature of long-lived emission lifetimes.However,to develop UOP materials with color-tunability is still a formidable challenge.Here,we report a class of UOP materials containing carbonyl,amino or amide groups,exhibiting colortunable persistent luminescence ranging from blue(458 nm)to yellow-green(508 nm)under different UV wavelength excitation.Taken theoretical and experimental results together,we conclude that the excitation dependent color-tunable UOP emission is ascribed to multiple emission centers from single molecular and aggregated states in crystal.Given color-tunable UOP feature,these materials are used to successfully realize visual UV-light detection.This finding not only provides a strategy to design new organic phosphorescent molecules with colorful emission,but also extends the scope of the applications of purely organic phosphorescent materials.
基金supported by the National Natural Science Foundation of China(NSFC,Nos.22165027,22061039,22001214)Gansu Province Innovation Star(No.2021CXZX-183).
文摘Recently,exploiting a novel supramolecular fabrication pathway have drawn great attention.To this endeavor,we firstly designed and reported an original light-activated platform based on the internal-driven forces of macrocyclic host by hiring the pillar[5]arene as the host molecule(H)and phenazine derivatives acting as an energetic guest molecule(G).Surprisingly,after adding the H solution into G system,the intensive fluorescence emission of the G molecule rapidly decreased under the irradiation of the UV-light(254 nm)until absolutely quenching.Delightfully,different from the traditional supramolecular host-guest interaction,the fluorescent emission of G molecule could be recovered after irradiating under the nature light.In view of this interesting observations,the interaction mechanism was carefully investigated by a series of characterizations.Those results suggested that the G molecule was easily threaded into the macrocyclic cavity(H)under the internal-driven forces induced by the UV-light irradiation,forming a 1:1 host-guest complex.Moreover,taking advantage of this especial feature,the light-activated platform of host-guest complex was further applied for ink-free light-driven printing materials,exhibiting great potential in the real application.
基金supported by the Open Foundation of Key Laboratory of Industrial Ecology and Environmental Engineering (No. KLIEEE-09-04)the Liaoning Doctoral Funds (No. 20111076)
文摘The effect of nanometer anatase TiO2 was investigated on the photocatalytic degradation of phenanthrene on soil surfaces under a variety of conditions.After being spiked with phenanthrene,soil samples loaded with different amounts of TiO2(0wt.%,1wt.%,2wt.%,3wt.%,and 4 wt.%) were exposed to UV-light irradiation for 25 hr.The results indicated that the photocatalytic degradation of phenanthrene followed the pseudo first-order kinetics.TiO2 significantly accelerated the degradation of phenanthrene with the half-life reduced from 45.90 to 31.36hr for TiO2 loading of 0wt.% and 4wt.%,respectively.In addition,the effects of H2O2,light intensity and humic acid on the degradation of phenanthrene were investigated.The degradation of phenanthrene increased with the concentration of H2O2,light intensity and the concentration of humic acids.It has been demonstrated that the photocatalytic method in the presence of nanometer anatase TiO2 was a very promising technology for the treatments of soil polluted with organic substances in the future.
基金Project supported by National Natural Science Foundation of China(51174020)
文摘Y and Eu co-doped nano-TiO2 photocatalysts were successfully prepared via a sol-gel method and characterized by X-ray diffraction(XRD), transmission electron microscopy(TEM), ultraviolet-visible spectrophotometry(UV-vis), photoluminescence(PL) and Fourier transform infrared(FT-IR) spectra. Experimental results indicated that Y and Eu doping inhibited the growth of crystalline size and the transformation from anatase to rutile phase and had the function of reducing particle reunion. At the same time, co-doping could also enhance the absorption in visible region and then narrowed the band gap. The photocatalytic activities of the samples were evaluated by the degradation of methylene blue(MB) under ultraviolet(UV) light irradiation, which showed much enhanced photocatalytic activities over un-doped TiO2. The degradation rate of 1.5% Y/Eu-TiO2 of methylene blue was 86%, which was about 5 times of that of un-doped TiO2, and the possible reasons for the improvement of photocatalytic activities were analyzed. In this experiment, the dopant amount of rare earth was 1.5% and the ratio of Y:Eu was 2:3 for the maximum photocatalytic degradation, and the sample calcined at 500 oC showed the best reactivity. For the best samples above, the removal rate of phenol under visble light was 53% whthin 2 h.
