With the significant discharge of antibiotic wastewater into the aquatic and terrestrial ecosystems, antibiotic pollution has become a serious problem and presents a hazardous risk to the environment. To address such ...With the significant discharge of antibiotic wastewater into the aquatic and terrestrial ecosystems, antibiotic pollution has become a serious problem and presents a hazardous risk to the environment. To address such issues, various investigations on the removal of antibiotics have been undertaken. Photocatalysis has received tremendous attention owing to its great potential in removing antibiotics from aqueous solutions via a green, economic, and effective process. However, such a technology employing traditional photocatalysts suffers from major drawbacks such as light absorption being restricted to the UV spectrum only and fast charge recombination. To overcome these issues, considerable effort has been directed towards the development of advanced visible light-driven photocatalysts. This mini review summarises recent research progress in the state-of-the-art design and fabrication of photocatalysts with visible-light response for photocatalytic degradation of antibiotic wastewater. Such design strategies involve the doping of metal and non-metal into ultraviolet light-driven photocatalysts, development of new semiconductor photocatalysts, construction of heterojunction photocatalysts, and fabrication of surface plasmon resonance-enhanced photocatalytic systems. Additionally, some perspectives on the challenges and future developments in the area of photocatalytic degradation of antibiotics are provided.展开更多
Plasmonic nonmetal semiconductors with localized surface plasmon resonance(LSPR)effects possess extended light-response ranges and can act as highly efficient H2 generation photocatalysts.Herein,an LSPR-enhanced 0D/2D...Plasmonic nonmetal semiconductors with localized surface plasmon resonance(LSPR)effects possess extended light-response ranges and can act as highly efficient H2 generation photocatalysts.Herein,an LSPR-enhanced 0D/2D CdS/MoO3‒x heterojunction has been synthesized by the growth of 0D CdS nanoparticles on 2D plasmonic MoO3‒x elliptical nanosheets via a simple coprecipitation method.Taking advantage of the LSPR effect of the MoO3‒x elliptical nanosheets,the light absorption of the CdS/MoO3‒x heterojunction was extended from 600 nm to the near-infrared region(1400 nm).Furthermore,the introduction of 2D plasmonic MoO3‒x elliptical nanosheets not only provided a platform for the growth of CdS nanoparticles,but also contributed to the construction of an LSPR-enhanced S-scheme structure due to the interface between the MoO3‒x and CdS,accelerating the separation of light-induced electrons and holes.Therefore,the CdS/MoO3‒x heterojunction exhibited higher photocatalytic H2 generation activity than pristine CdS under visible light irradiation,including under 420,450,550,and 650 nm monochromic light,as well as improved photo-corrosion performance.展开更多
Localized surface plasmon resonance(LSPR)can be supported by metallic nanoparticles and engineered nanostructures.An understanding of the spatially resolved near-field properties and dynamics of LSPR is important,but ...Localized surface plasmon resonance(LSPR)can be supported by metallic nanoparticles and engineered nanostructures.An understanding of the spatially resolved near-field properties and dynamics of LSPR is important,but remains experimentally challenging.We report experimental studies toward this aim using photoemission electron microscopy(PEEM)with high spatial resolution of sub-10 nm.Various engineered gold nanostructure arrays(such as rods,nanodisk-like particles and dimers)are investigated via PEEM using near-infrared(NIR)femtosecond laser pulses as the excitation source.When the LSPR wavelengths overlap the spectrum of the femtosecond pulses,the LSPR is efficiently excited and promotes multiphoton photoemission,which is correlated with the local intensity of the metallic nanoparticles in the near field.Thus,the local field distribution of the LSPR on different Au nanostructures can be directly explored and discussed using the PEEM images.In addition,the dynamics of the LSPR is studied by combining interferometric time-resolved pump-probe technique and PEEM.Detailed information on the oscillation and dephasing of the LSPR field can be obtained.The results identify PEEM as a powerful tool for accessing the near-field mapping and dynamic properties of plasmonic nanostructures.展开更多
An overview of recent researches of surface plasmon resonance （SPR） sensing technology in Laboratory of Science and Technology of Micro-Nano Optics （LMNO）, University of Science and Technology of China, is present...An overview of recent researches of surface plasmon resonance （SPR） sensing technology in Laboratory of Science and Technology of Micro-Nano Optics （LMNO）, University of Science and Technology of China, is presented. Some novel SPR sensors, such as sensors based on metallic grating, metal-insulator-metal （MIM） nanoring and optical fiber, are designed or fabricated and tested. The sensor based on localized surface plasmon resonance （LSPR） of metallic nanoparticles is also be summarized. Because of the coupling of propagating surface plasmons and localized surface plasmons, the localized electromagnetic field is extremely enhanced, which is applied to surface-enhanced Raman scattering （SERS） and fluorenscence enhancement. Future prospects of SPR and/or LSPR sensing developments and applications are atso discussed.展开更多
Gas identification and concentration measurements are important for both understanding and monitoring a variety of phenomena from industrial processes to environmental change.Here a novel mid-IR plasmonic gas sensor w...Gas identification and concentration measurements are important for both understanding and monitoring a variety of phenomena from industrial processes to environmental change.Here a novel mid-IR plasmonic gas sensor with on-chip direct readout is proposed based on unity integration of narrowband spectral response,localized field enhancement and thermal detection.A systematic investigation consisting of both optical and thermal simulations for gas sensing is presented for the first time in three sensing modes including refractive index sensing,absorption sensing and spectroscopy,respectively.It is found that a detection limit less than 100 ppm for CO2 could be realized by a combination of surface plasmon resonance enhancement and metal-organic framework gas enrichment with an enhancement factor over 8000 in an ultracompact optical interaction length of only several microns.Moreover,on-chip spectroscopy is demonstrated with the compressive sensing algorithm via a narrowband plasmonic sensor array.An array of 80 such sensors with an average resonance linewidth of 10 nm reconstructs the CO2 molecular absorption spectrum with the estimated resolution of approximately 0.01 nm far beyond the state-of-the-art spectrometer.The novel device design and analytical method are expected to provide a promising technique for extensive applications of distributed or portable mid-IR gas sensor.展开更多
Among the many novel photocatalytic systems developed in very recent years,plasmonic photocatalytic composites possess great potential for use in applications and are one of the most intensively investigated photocata...Among the many novel photocatalytic systems developed in very recent years,plasmonic photocatalytic composites possess great potential for use in applications and are one of the most intensively investigated photocatalytic systems owing to their high solar energy utilization efficiency.In these composites,the plasmonic nanoparticles(PNPs)efficiently absorb solar light through localized surface plasmon resonance and convert it into energetic electrons and holes in the nearby semiconductor.This energy transfer from PNPs to semiconductors plays a decisive role in the overall photocatalytic performance.Thus,the underlying physical mechanism is of great scientific and technological importance and is one of the hottest topics in the area of plasmonic photocatalysts.In this review,we examine the very recent advances in understanding the energy transfer process in plasmonic photocatalytic composites,describing both the theoretical basis of this process and experimental demonstrations.The factors that affect the energy transfer efficiencies and how to improve the efficiencies to yield better photocatalytic performance are also discussed.Furthermore,comparisons are made between the various energy transfer processes,emphasizing their limitations/benefits for efficient operation of plasmonic photocatalysts.展开更多
Layer-by-layer gold nanoparticles are used to generate photocurrent in an environmentally-friendly plasmon-sensitized solar cell towing to surface plasmon resonance.The efficiency of the photoelectric conversion of go...Layer-by-layer gold nanoparticles are used to generate photocurrent in an environmentally-friendly plasmon-sensitized solar cell towing to surface plasmon resonance.The efficiency of the photoelectric conversion of gold nanoparticle layers is increased as the intensity of surface plasmon resonance increases.We also explain the experimental results by modeling the phenomenon of charge separation and photocurrent formation,and the relationship between surface plasmon resonance and photocurrent formation,which has potential application in plasmon-sensitized solar cells and plasmonic solar cells in the future.展开更多
Given the challenges brought by the shortage of freshwater resources,solar water evaporation has been regarded as one of the most promising technologies for harnessing abundant sunlight to harvest clean water from the...Given the challenges brought by the shortage of freshwater resources,solar water evaporation has been regarded as one of the most promising technologies for harnessing abundant sunlight to harvest clean water from the sea.Nanostructured metals have attracted extensive attention in solar water evaporation due to their localized surface plasmon resonance effect,but highly porous metallic films with high evaporation efficiency are challenging.Herein,a self-supporting black nanoporous silver(NP-Ag)film was fabricated by dealloying of an extremely dilute Al99Ag1 alloy.The choice of the dilute precursor guarantees the formation of the NP-Ag film with high porosity(96.5%)and low density(0.3703 g·cm^(-3),even smaller than the lightest metal lithium).The three-dimensional ligament-channel network structure and the nanoscale(14.6 nm)of ligaments enable the NP-Ag film to exhibit good hydrophilicity and broadband absorption over 200‒2,500 nm.More importantly,the solar evaporator based on the NP-Ag film shows efficient solar steam generation,including the efficiency of 92.6%,the evaporation rate of 1.42 kg·m^(-2)·h^(-1)and good cycling stability under one sun irradiation.Moreover,the NP-Ag film exhibits acceptable seawater desalination property with the ion rejection for Mg^(2+),Ca^(2+),K^(+)and Na^(+)more than 99.3%.Our findings could provide a new idea and inspiration for the design and fabrication of metal-based photothermal films in real solar evaporation applications.展开更多
Bi2WO6 is a typical visible-light-responsive semiconductor photocatalyst with a layered structure.However,the relatively large bandgap(2.6–2.8 eV)and quick recombination of photo-generated carriers result in its low ...Bi2WO6 is a typical visible-light-responsive semiconductor photocatalyst with a layered structure.However,the relatively large bandgap(2.6–2.8 eV)and quick recombination of photo-generated carriers result in its low quantum efficiency.In this paper,Bi-nanospheres-modified flower-like Bi2WO6 was successfully prepared by solvothermal treatment of Bi2WO6 powders in Bi(NO3)3 solution using ethylene glycol as reductant.The photoreactivity of this photocatalyst was evaluated by the oxidation of NO in a continuous-flow reactor under irradiation by a visible LED lamp(λ>400 nm).It was found that both Bi nanospheres and flower-like Bi2WO6 precursor exhibit very poor photocatalytic activity with NO removal rates of only 7.7%and 8.6%,respectively.The photoreactivity of Bi/Bi2WO6 was found to steadily increase from 12.3%to 53.1%with increase in the amount of Bi nanospheres from 0 to 10 wt%.However,with further increase in the loading amount of Bi nanospheres,the photoreactivity of Bi/Bi2WO6 hybridized photocatalyst begins to decrease,possibly due to the light filtering by the Bi nanospheres.The enhanced visible photoreactivity of Bi/Bi2WO6 towards NO abatement was attributed to surface plasmon resonance driven interfacial charge separation.The excellent stability of Bi/Bi2WO6 hybridized photocatalyst towards NO oxidation demonstrates its potential for applications such as air purification.展开更多
Human acidic and basic fibroblast growth factors (aFGF and bFGF) are classic and well characterized members of the heparin binding growth factor family. Heparin is generally thought to play an extremely important rol...Human acidic and basic fibroblast growth factors (aFGF and bFGF) are classic and well characterized members of the heparin binding growth factor family. Heparin is generally thought to play an extremely important role in regulating aFGF and bFGF bioactivities through its strong binding with them. In order to unravel the mechanism of the interactions between heparin and FGFs, and evaluate the importance of heparin sulfate groups' binding with FGFs, surface plasmon resonance analyses were performed using IAsys Cuvettes System. Heparin and its regioselectively desulfated derivatives were immobilized on the cuvettes. aFGF and bFGF solutions with different concentrations were pipetted into the cuvettes and the progress of the interaction was monitored in real\|time by Windows based software, yielding kinetic and equilibrium constants for these interactions. In addition, in order to reduce the delicate difference among the cuvettes, inhibition analyses of mixture of FGFs and immobilized native heparin by modified heparins were also done. The data from these two methods were similar, indicating that all sulfate groups at 2 O, 6 O and N in heparin were required for the binding to aFGF; and that their contribution to the binding was in the order 2 O, N and 6 O sulfate group. In contrast, definite contribution of the 6 O sulfate group to the binding with bFGF was most apparent, while the other two sulfate groups appeared to be necessary in the order 2 O and N sulfate group. These methods established here can be used for analysing the effect of sulfate groups in heparin on the binding with other human FGF members or other heparin binding proteins.展开更多
Narrow-band BiOI photocatalysts usually suffer from low photocatalysis efficiency under visible light exposure because of rapid charge recombination. In this work, to overcome this deficiency of photosensitive BiOI, o...Narrow-band BiOI photocatalysts usually suffer from low photocatalysis efficiency under visible light exposure because of rapid charge recombination. In this work, to overcome this deficiency of photosensitive BiOI, oxygen vacancies, Bi particles, and Bi2O2CO3 were co-induced in BiOI via a facile in situ assembly method at room temperature using NaBH4 as the reducing agent. In the synthesized ternary Bi/BiOI/(BiO)2CO3, the oxygen vacancies, dual heterojunctions (i.e., Bi/BiOI and Bi- OI/(BiO)2CO3), and surface plasmon resonance effect of the Bi particles contributed to efficient electron-hole separation and an increase in charge carrier concentration, thus boosting the overall visible light photocatalysis efficiency. The as-prepared catalysts were applied for the removal of NO in concentrations of parts per billion from air in continuous air flow under visible light illumination. Bi/BiOI/(BiO)2CO3 exhibited a highly enhanced NO removal ratio of 50.7%, much higher than that of the pristine BiOI (1.2%). Density functional theory calculations and experimental results revealed that the Bi/BiOI/(BiO)2CO3 composites promoted the production of reactive oxygen species for photocatalytic NO oxidation. Thus, this work provides a new strategy to modify narrow-band semiconductors and explore other bismuth-containing heterostructured visible-light-driven photocatalysts.展开更多
基金supported by the National Natural Science Foundation of China(21421001,21276116,21477050,21301076,21303074)Natural Science Foundation of Jiangsu Province(BK20140530,BK20150482)+5 种基金China Postdoctoral Science Foundation(2015M570409)Chinese-German Cooperation Research Project(GZ1091)Program for High-Level Innovative and Entrepreneurial Talents in Jiangsu ProvinceProgram for New Century Excellent Talents in University(NCET-13-0835)Henry Fok Education Foundation(141068)Six Talents Peak Project in Jiangsu Province(XCL-025)~~
文摘With the significant discharge of antibiotic wastewater into the aquatic and terrestrial ecosystems, antibiotic pollution has become a serious problem and presents a hazardous risk to the environment. To address such issues, various investigations on the removal of antibiotics have been undertaken. Photocatalysis has received tremendous attention owing to its great potential in removing antibiotics from aqueous solutions via a green, economic, and effective process. However, such a technology employing traditional photocatalysts suffers from major drawbacks such as light absorption being restricted to the UV spectrum only and fast charge recombination. To overcome these issues, considerable effort has been directed towards the development of advanced visible light-driven photocatalysts. This mini review summarises recent research progress in the state-of-the-art design and fabrication of photocatalysts with visible-light response for photocatalytic degradation of antibiotic wastewater. Such design strategies involve the doping of metal and non-metal into ultraviolet light-driven photocatalysts, development of new semiconductor photocatalysts, construction of heterojunction photocatalysts, and fabrication of surface plasmon resonance-enhanced photocatalytic systems. Additionally, some perspectives on the challenges and future developments in the area of photocatalytic degradation of antibiotics are provided.
文摘Plasmonic nonmetal semiconductors with localized surface plasmon resonance(LSPR)effects possess extended light-response ranges and can act as highly efficient H2 generation photocatalysts.Herein,an LSPR-enhanced 0D/2D CdS/MoO3‒x heterojunction has been synthesized by the growth of 0D CdS nanoparticles on 2D plasmonic MoO3‒x elliptical nanosheets via a simple coprecipitation method.Taking advantage of the LSPR effect of the MoO3‒x elliptical nanosheets,the light absorption of the CdS/MoO3‒x heterojunction was extended from 600 nm to the near-infrared region(1400 nm).Furthermore,the introduction of 2D plasmonic MoO3‒x elliptical nanosheets not only provided a platform for the growth of CdS nanoparticles,but also contributed to the construction of an LSPR-enhanced S-scheme structure due to the interface between the MoO3‒x and CdS,accelerating the separation of light-induced electrons and holes.Therefore,the CdS/MoO3‒x heterojunction exhibited higher photocatalytic H2 generation activity than pristine CdS under visible light irradiation,including under 420,450,550,and 650 nm monochromic light,as well as improved photo-corrosion performance.
基金This study was supported by funding from the Ministry of Education,Culture,Sports,Science,and Technology of Japan:KAKENHI Grant-in-Aid for Scientific Research No.23225006,Nanotechnology Platform(Hokkaido University)and the Low-Carbon Research Network of Japan.
文摘Localized surface plasmon resonance(LSPR)can be supported by metallic nanoparticles and engineered nanostructures.An understanding of the spatially resolved near-field properties and dynamics of LSPR is important,but remains experimentally challenging.We report experimental studies toward this aim using photoemission electron microscopy(PEEM)with high spatial resolution of sub-10 nm.Various engineered gold nanostructure arrays(such as rods,nanodisk-like particles and dimers)are investigated via PEEM using near-infrared(NIR)femtosecond laser pulses as the excitation source.When the LSPR wavelengths overlap the spectrum of the femtosecond pulses,the LSPR is efficiently excited and promotes multiphoton photoemission,which is correlated with the local intensity of the metallic nanoparticles in the near field.Thus,the local field distribution of the LSPR on different Au nanostructures can be directly explored and discussed using the PEEM images.In addition,the dynamics of the LSPR is studied by combining interferometric time-resolved pump-probe technique and PEEM.Detailed information on the oscillation and dephasing of the LSPR field can be obtained.The results identify PEEM as a powerful tool for accessing the near-field mapping and dynamic properties of plasmonic nanostructures.
基金This work is supported by the National Key Basic Research Program of China （No. 2011cb301802）, and Key Program of National Natural Science Foundation of China （No. 60736037）. The authors gratefully acknowledge Prof. Y. H. Lu, D. G. Zhang, and P. Wang for many helpful discussions.
文摘An overview of recent researches of surface plasmon resonance （SPR） sensing technology in Laboratory of Science and Technology of Micro-Nano Optics （LMNO）, University of Science and Technology of China, is presented. Some novel SPR sensors, such as sensors based on metallic grating, metal-insulator-metal （MIM） nanoring and optical fiber, are designed or fabricated and tested. The sensor based on localized surface plasmon resonance （LSPR） of metallic nanoparticles is also be summarized. Because of the coupling of propagating surface plasmons and localized surface plasmons, the localized electromagnetic field is extremely enhanced, which is applied to surface-enhanced Raman scattering （SERS） and fluorenscence enhancement. Future prospects of SPR and/or LSPR sensing developments and applications are atso discussed.
基金We are grateful for financial supports from National Key Research and Development Program of China(No.2019YFB2203402)National Natural Science Foundation of China(Nos.11774383,11774099,11874029)+3 种基金Guangdong Science and Technology Program International Cooperation Program(2018A050506039)Guangdong Natural Science Founds for Distinguished Young Scholars(No.2020B151502074),Pearl River Talent Plan Program of Guangdong(No.2019QN01X120)Fundamental Research Funds for the Central Universities,Royal Society Newton Advanced Fellowship(No.NA140301)Key Frontier Scientific Research Program of the Chinese Academy of Sciences(No.QYZDBSSW-JSC014).
文摘Gas identification and concentration measurements are important for both understanding and monitoring a variety of phenomena from industrial processes to environmental change.Here a novel mid-IR plasmonic gas sensor with on-chip direct readout is proposed based on unity integration of narrowband spectral response,localized field enhancement and thermal detection.A systematic investigation consisting of both optical and thermal simulations for gas sensing is presented for the first time in three sensing modes including refractive index sensing,absorption sensing and spectroscopy,respectively.It is found that a detection limit less than 100 ppm for CO2 could be realized by a combination of surface plasmon resonance enhancement and metal-organic framework gas enrichment with an enhancement factor over 8000 in an ultracompact optical interaction length of only several microns.Moreover,on-chip spectroscopy is demonstrated with the compressive sensing algorithm via a narrowband plasmonic sensor array.An array of 80 such sensors with an average resonance linewidth of 10 nm reconstructs the CO2 molecular absorption spectrum with the estimated resolution of approximately 0.01 nm far beyond the state-of-the-art spectrometer.The novel device design and analytical method are expected to provide a promising technique for extensive applications of distributed or portable mid-IR gas sensor.
基金supported by the National Basic Research Program of China(973 program,2013CB632401)the National Science Foundation of China(Grant NOs 11374190 and 21333006)the Taishan Scholar Program of Shandong and 111 Project B13029.
文摘Among the many novel photocatalytic systems developed in very recent years,plasmonic photocatalytic composites possess great potential for use in applications and are one of the most intensively investigated photocatalytic systems owing to their high solar energy utilization efficiency.In these composites,the plasmonic nanoparticles(PNPs)efficiently absorb solar light through localized surface plasmon resonance and convert it into energetic electrons and holes in the nearby semiconductor.This energy transfer from PNPs to semiconductors plays a decisive role in the overall photocatalytic performance.Thus,the underlying physical mechanism is of great scientific and technological importance and is one of the hottest topics in the area of plasmonic photocatalysts.In this review,we examine the very recent advances in understanding the energy transfer process in plasmonic photocatalytic composites,describing both the theoretical basis of this process and experimental demonstrations.The factors that affect the energy transfer efficiencies and how to improve the efficiencies to yield better photocatalytic performance are also discussed.Furthermore,comparisons are made between the various energy transfer processes,emphasizing their limitations/benefits for efficient operation of plasmonic photocatalysts.
基金This work was financially supported by the National Science Council of Taiwan,No.100-2218-E-259-003-MY3,which is gratefully acknowledged.
文摘Layer-by-layer gold nanoparticles are used to generate photocurrent in an environmentally-friendly plasmon-sensitized solar cell towing to surface plasmon resonance.The efficiency of the photoelectric conversion of gold nanoparticle layers is increased as the intensity of surface plasmon resonance increases.We also explain the experimental results by modeling the phenomenon of charge separation and photocurrent formation,and the relationship between surface plasmon resonance and photocurrent formation,which has potential application in plasmon-sensitized solar cells and plasmonic solar cells in the future.
基金the financial support by the National Natural Science Foundation of China(No.51871133)the Taishan Scholar Foundation of Shandong Province,the Key Research and Development Program of Shandong Province(No.2021ZLGX01)the program of Jinan Science and Technology Bureau(No.2019GXRC001).
文摘Given the challenges brought by the shortage of freshwater resources,solar water evaporation has been regarded as one of the most promising technologies for harnessing abundant sunlight to harvest clean water from the sea.Nanostructured metals have attracted extensive attention in solar water evaporation due to their localized surface plasmon resonance effect,but highly porous metallic films with high evaporation efficiency are challenging.Herein,a self-supporting black nanoporous silver(NP-Ag)film was fabricated by dealloying of an extremely dilute Al99Ag1 alloy.The choice of the dilute precursor guarantees the formation of the NP-Ag film with high porosity(96.5%)and low density(0.3703 g·cm^(-3),even smaller than the lightest metal lithium).The three-dimensional ligament-channel network structure and the nanoscale(14.6 nm)of ligaments enable the NP-Ag film to exhibit good hydrophilicity and broadband absorption over 200‒2,500 nm.More importantly,the solar evaporator based on the NP-Ag film shows efficient solar steam generation,including the efficiency of 92.6%,the evaporation rate of 1.42 kg·m^(-2)·h^(-1)and good cycling stability under one sun irradiation.Moreover,the NP-Ag film exhibits acceptable seawater desalination property with the ion rejection for Mg^(2+),Ca^(2+),K^(+)and Na^(+)more than 99.3%.Our findings could provide a new idea and inspiration for the design and fabrication of metal-based photothermal films in real solar evaporation applications.
基金supported by the National Natural Science Foundation of China(51672312,21373275,51808080,21571192)the Fundamental Research Funds for the Central Univsrsity,South-Central University for Nationalities(CZT19006)+2 种基金the Natural Science Foundation Project of CQ CSTC(cstc2018jcyjA 3794)China "post-doctoral innovative talent support program"(BX20180056)China Postdoctoral Science Foundation(2018M643788XB)~~
文摘Bi2WO6 is a typical visible-light-responsive semiconductor photocatalyst with a layered structure.However,the relatively large bandgap(2.6–2.8 eV)and quick recombination of photo-generated carriers result in its low quantum efficiency.In this paper,Bi-nanospheres-modified flower-like Bi2WO6 was successfully prepared by solvothermal treatment of Bi2WO6 powders in Bi(NO3)3 solution using ethylene glycol as reductant.The photoreactivity of this photocatalyst was evaluated by the oxidation of NO in a continuous-flow reactor under irradiation by a visible LED lamp(λ>400 nm).It was found that both Bi nanospheres and flower-like Bi2WO6 precursor exhibit very poor photocatalytic activity with NO removal rates of only 7.7%and 8.6%,respectively.The photoreactivity of Bi/Bi2WO6 was found to steadily increase from 12.3%to 53.1%with increase in the amount of Bi nanospheres from 0 to 10 wt%.However,with further increase in the loading amount of Bi nanospheres,the photoreactivity of Bi/Bi2WO6 hybridized photocatalyst begins to decrease,possibly due to the light filtering by the Bi nanospheres.The enhanced visible photoreactivity of Bi/Bi2WO6 towards NO abatement was attributed to surface plasmon resonance driven interfacial charge separation.The excellent stability of Bi/Bi2WO6 hybridized photocatalyst towards NO oxidation demonstrates its potential for applications such as air purification.
文摘Human acidic and basic fibroblast growth factors (aFGF and bFGF) are classic and well characterized members of the heparin binding growth factor family. Heparin is generally thought to play an extremely important role in regulating aFGF and bFGF bioactivities through its strong binding with them. In order to unravel the mechanism of the interactions between heparin and FGFs, and evaluate the importance of heparin sulfate groups' binding with FGFs, surface plasmon resonance analyses were performed using IAsys Cuvettes System. Heparin and its regioselectively desulfated derivatives were immobilized on the cuvettes. aFGF and bFGF solutions with different concentrations were pipetted into the cuvettes and the progress of the interaction was monitored in real\|time by Windows based software, yielding kinetic and equilibrium constants for these interactions. In addition, in order to reduce the delicate difference among the cuvettes, inhibition analyses of mixture of FGFs and immobilized native heparin by modified heparins were also done. The data from these two methods were similar, indicating that all sulfate groups at 2 O, 6 O and N in heparin were required for the binding to aFGF; and that their contribution to the binding was in the order 2 O, N and 6 O sulfate group. In contrast, definite contribution of the 6 O sulfate group to the binding with bFGF was most apparent, while the other two sulfate groups appeared to be necessary in the order 2 O and N sulfate group. These methods established here can be used for analysing the effect of sulfate groups in heparin on the binding with other human FGF members or other heparin binding proteins.
基金supported by the National Natural Science Foundation of China(21501016,21777011,51871037,51501024)the Innovative Research Team of Chongqing(CXTDG201602014)+1 种基金the Key Natural Science Foundation of Chongqing(cstc2017jcyjBX0052)the Plan for "National Youth Talents" of the Organization Department of the Central Committee~~
文摘Narrow-band BiOI photocatalysts usually suffer from low photocatalysis efficiency under visible light exposure because of rapid charge recombination. In this work, to overcome this deficiency of photosensitive BiOI, oxygen vacancies, Bi particles, and Bi2O2CO3 were co-induced in BiOI via a facile in situ assembly method at room temperature using NaBH4 as the reducing agent. In the synthesized ternary Bi/BiOI/(BiO)2CO3, the oxygen vacancies, dual heterojunctions (i.e., Bi/BiOI and Bi- OI/(BiO)2CO3), and surface plasmon resonance effect of the Bi particles contributed to efficient electron-hole separation and an increase in charge carrier concentration, thus boosting the overall visible light photocatalysis efficiency. The as-prepared catalysts were applied for the removal of NO in concentrations of parts per billion from air in continuous air flow under visible light illumination. Bi/BiOI/(BiO)2CO3 exhibited a highly enhanced NO removal ratio of 50.7%, much higher than that of the pristine BiOI (1.2%). Density functional theory calculations and experimental results revealed that the Bi/BiOI/(BiO)2CO3 composites promoted the production of reactive oxygen species for photocatalytic NO oxidation. Thus, this work provides a new strategy to modify narrow-band semiconductors and explore other bismuth-containing heterostructured visible-light-driven photocatalysts.
