A simple two-step hydrothermal method synthesized four different CdS/Fe_(3)O_(4)photocatalysts with varying ratios of mass of CdS to Fe_(3)O_(4).The composition and morphology of the prepared samples were investigated...A simple two-step hydrothermal method synthesized four different CdS/Fe_(3)O_(4)photocatalysts with varying ratios of mass of CdS to Fe_(3)O_(4).The composition and morphology of the prepared samples were investigated using X-ray diffraction(XRD),Raman spectrum,X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),and transmission electron microscopy(TEM).Solid UV reflectance spectra testing found that CdS/Fe_(3)O_(4)nanocomposites had good light absorption throughout the spectral range,promoting their photocatalytic properties.Under visible light irradiation,CdS/Fe_(3)O_(4)(2∶5)with a mass ratio of 2∶5 exhibited excellent photocatalytic perfor-mance,with a degradation rate of 98.8%for rhodamine B.Furthermore,after five cycles of photocatalytic degrada-tion reaction,the rhodamine B degradation rate remained at 96.2%,indicating that the photocatalysts have good pho-tocatalytic stability.展开更多
We investigated the removal of the organic dye rhodamine B in wastewater with recyclable AgBr/polypyrrole(PPy)nano-photocatalysts.With PPy as an active base for electron transfer,and hexadecyltrimethylammonium bromide...We investigated the removal of the organic dye rhodamine B in wastewater with recyclable AgBr/polypyrrole(PPy)nano-photocatalysts.With PPy as an active base for electron transfer,and hexadecyltrimethylammonium bromide(CTAB)as both the soft-templating agent and the bromine source,a series of AgBr/PPy nano-photocatalysts containing various proportions of silver were prepared in a convenient one-step synthesis procedure.The synthesized catalysts were characterized by TG analysis to reveal that,in comparison with pure PPy,the interaction between PPy and AgBr led to increased thermal stability.Chemical combination of PPy and AgBr was observed through XRD and XPS analyses.For the morphology study,the AgBr particles were found to be well dispersed in the PPy nanowire network from SEM results.In the photodegradation experiments,up to 92%rhodamine B was degraded by the AgBr/PPy catalysts in the period of 1 hour under 254 nm UV light.The catalysts could maintain 60%catalytic efficiency after 3 cycles in the recyclability test.展开更多
A plasmonic effect of silver nanoparticles (AgNPs) in dye-sensitized solar cells (DSSCs) is studied. In this investigation, the efficiency of dye-sensitized solar cells has been remarkably increased by infusion of syn...A plasmonic effect of silver nanoparticles (AgNPs) in dye-sensitized solar cells (DSSCs) is studied. In this investigation, the efficiency of dye-sensitized solar cells has been remarkably increased by infusion of synthesized silver nanoparticles into the TiO<sub>2</sub> photoanode. Rhodaminederivative RdS1 was synthesized by microwave-assisted condensation of hydrazide and 3-for-mylchromone. The synthesized silver nanoparticles were characterized with UV/Vis absorption spectroscopy and transmission electron microscopy. The interfacial charge transport phenomena of the dye-sensitized solar cell (DSSCs) are determined by electrochemical impedance spectroscopy and the corresponding efficiencies are calculated using current-voltage (I-V) curve. The solar cell photoanode with silver nanoparticles infused with RdS1 in titanium dioxide had the highest solar-to-electric power efficiency at 0.17%.展开更多
The present work deals on one hand with the valorization of wastes plastics, polyethylene terephthalate (PET) and Canarium schweinfurthii (CS) for the preparation of polyethylene terephthalate activated carbon (PETAC)...The present work deals on one hand with the valorization of wastes plastics, polyethylene terephthalate (PET) and Canarium schweinfurthii (CS) for the preparation of polyethylene terephthalate activated carbon (PETAC) and Canarium schweinfurthii/polyethylene terephthalate activated carbon (CS/PETAC). These adsorbents, on the other hand, were used for removal Rhodamine B (RhB) in an aqueous solution. PET and CS precursors were subjected to thermogravimetric analysis (TGA) and differential scanning colorimetry (DSC). Meanwhile PETAC and CS/PETAC were characterized using scanning electron microscopy-energy dispersive spectrometry (SEM-EDS), X-ray fluorescence (XRF), Fourier transformed infrared spectroscopy (FT-IR) and nitrogen adsorption/desorption (N<sub>2</sub>-BET). The N<sub>2</sub>-BET results revealed an increase of the specific surface area from 6.75 m<sup>2</sup>/g to 1282.0 m<sup>2</sup>/g for PETAC and CS/PETAC. The results of characterization indicated the key role played by plastic wastes to enhance the structural and functional properties of CS/PETAC. The RhB removal from the aqueous solution onto PETAC and CS/PETAC was found to be independent of pH, with an optimal contact time of RhB removal within 10 min for materials. The non-linear adsorption isotherm data for the adsorption process showed that the Langmuir and Freundlich models best fitted the RhB adsorption onto PETAC meanwhile only the Freundlich adsorption isotherm gave the best fit for CS/PETAC according to the correlation coefficient value closed to unity. The pseudo-first and pseudo-second-order kinetic models best described the RhB dye removal on both adsorbents. Additionally, the Elovich model confirmed that chemisorption was the main mechanism followed. These findings proved that CS seeds and PET wastes are low-cost precursors that should be given an added value by transforming them into an outstanding carbon material for dye removal in liquid effluent.展开更多
A series of WO3 samples with different crystalline phases were prepared by the thermal decomposition method from ammonium tungstate hydrate.X-ray diffraction（XRD）,scanning electron microscopy（SEM）,high-resolution ...A series of WO3 samples with different crystalline phases were prepared by the thermal decomposition method from ammonium tungstate hydrate.X-ray diffraction（XRD）,scanning electron microscopy（SEM）,high-resolution transmission electron microscopy（HRTEM）,X-ray photoelectron spectroscopy,and N2 adsorption-desorption were used to characterize the crystalline phase,morphology,particle size,chemical composition,and surface area of the WO3 samples.The formation of hexagonal（h-WO3） and monoclinic（m-WO3） crystal structures of WO3 at different temperatures or different times was confirmed by XRD.m-WO3 is formed at 600 ℃,while m-WO3 starts to transform into h-WO3 at 800℃.However,h-WO3,which forms at 800℃,may transform into m-WO3 by increasing the calcination temperature to 1000℃.SEM results indicate that m-WO3 particles exhibit a bulky shape with heavy aggregates,while h-WO3 particles exhibit a rod-like shape.Moreover,m-WO3 crystals are sporadically patched on the surface of the h-WO3 rod-like particles,resulting in the exposure of both m-WO3 and h-WO3 on the surface.It is observed that the monoclinic phase（m-WO3）/hexagonal phase（h-WO3） junction was fabricated by tuning the calcination temperature and calcination time.The relative ratios between m-WO3 and h-WO3 in the phase junction can readily be tailored by control of the calcination time.The photocatalytic activities of WO3 with different crystalline phases were evaluated by the photocatalytic degradation of rhodamine B as a model pollutant.A higher photocatalytic activity was observed in the WO3 sample with the m-WO3/h-WO3junction as compared with the sample with only m-WO3.The improvement of photocatalytic activity can be attributed to the reduction of the electron-hole recombination rate owing to the formation of the phase junction,whose presence has been confirmed by HRTEM and photoluminescence spectra.展开更多
Polarization variable-angle synchronous fluorescence spectrometry was proposed to determine samples in turbid solution. A mixture of fluorescein, rhodamine 6G and rhodamine B was used to evaluate the technique. The ba...Polarization variable-angle synchronous fluorescence spectrometry was proposed to determine samples in turbid solution. A mixture of fluorescein, rhodamine 6G and rhodamine B was used to evaluate the technique. The background caused by scattering light was decreased remarkably. The limits of detection were 0.6 ng/ml for fluorescein, 2.3 ng/ml for rhodamine 6G and 4.1 ng/ml for rhodamine B, respectively.展开更多
In acid medium, rhodamine B（RhB）, rhodamine S（RhS）, rhodamine 6G（RhG） and butyl rhodamine B（b-RhB） have a fluorescence peak at 580, 549, 553 and 580nm, respectively. BrO^-3 oxidizes excess I^- into I^-3 Rhodam...In acid medium, rhodamine B（RhB）, rhodamine S（RhS）, rhodamine 6G（RhG） and butyl rhodamine B（b-RhB） have a fluorescence peak at 580, 549, 553 and 580nm, respectively. BrO^-3 oxidizes excess I^- into I^-3 Rhodamine dyes combine I^-3 to form ion association nanoparticles, resulting in fluorescence quenching at 580, 549, 553 and 580 rim, respectively. The fluorescence quenching intensity is proportional to the concentration of BrO^-3 in the range of 0.020 4 - 0.710 μg/mL for RhB, 0.025 - 0. 512μg/mL for RhS, 0.025 - 0.260 μg/mL for RhG, 0.025 - 1.28μg/mL for b-RhB, respectively. In the four systems, RhB system has good stability and high sensitivity. Thus, a simple, sensitive fluorescence method was proposed for the determination of BrO^-3 in commercial bread additives and flours, with satisfactory results. The results of the fluorescence spectra and scan electron microscopy show that the formation of about 60 ran （RhB - I^-3） n association nanoparticles and the interface between the nanoparticles and solution are main factors that cause the fluorescence quenching.展开更多
We investigate the fluorescence quenching of Rhodamine 6G （R6G）, a well known laser dye with a high fluorescence quantum yield, by as-synthesized graphene oxide （GO） in aqueous solution, which is found to be rathe...We investigate the fluorescence quenching of Rhodamine 6G （R6G）, a well known laser dye with a high fluorescence quantum yield, by as-synthesized graphene oxide （GO） in aqueous solution, which is found to be rather efficient. By means of steady-state and time-resolved fluorescence spectroscopy combined with detailed analysis about the linear absorption vari- ation for this R6G-GO system, the pertinent quenching mechanism has been elucidated to be a combination of dynamic and static quenching. Possible ground-state complexes be- tween R6G and GO during the static quenching have also been suggested. Furthermore, the direction of photoindueed electron transfer between R6G and GO has been discussed.展开更多
The photocatalytic degradation of Rhodamine B （RhB） was carried out using TiO2 supported on activated carbon （TiO2-AC） under microwave irradiation. Composite catalyst TiO2-AC was prepared and characterized using X...The photocatalytic degradation of Rhodamine B （RhB） was carried out using TiO2 supported on activated carbon （TiO2-AC） under microwave irradiation. Composite catalyst TiO2-AC was prepared and characterized using X-ray diffraction （XRD）, transmission electron microscopy （TEM） and Brunauer-Emmett-Teller （BET）. In the process of microwave-enhanced photocatalysis （MPC）, RhB （30 mg/L） was almost completely decoloured in 10 min, and the mineralization efficiency was 96.0% in 20 min. The reaction rate constant of RhB in MPC using TiO2-AC by pseudo first-order reaction kinetics was 4.16 times of that using Degussa P25. Additionally, according to gas chromatography/mass spectrometry （GC/MS） and liquid chromatography/mass spectrometry （LC/MS） identification, the major intermediates of RhB in MPC included two kinds of N-de-ethylation intermediates （N,N-diethyl-N＇-ethyl-rhodamine （DER））, oxalic acid, malonic acid, snccinic acid, and phthalic acid, maleic acid, 3-nitrobenzoic acid, and so on. The degradation of RhB in MPC was mainly attributed to the destruction of the conjugated structure, and then the intermediates transformed to acid molecules which were mineralized to water and carbon dioxide.展开更多
A PbO2/Sb-SnO2/TiO2 nanotube array composite electrode was successfully synthesized and its electrochemical oxidation properties were investigated.Field-emission scanning electron microscopy(FE-SEM)and X-ray diffracti...A PbO2/Sb-SnO2/TiO2 nanotube array composite electrode was successfully synthesized and its electrochemical oxidation properties were investigated.Field-emission scanning electron microscopy(FE-SEM)and X-ray diffraction(XRD)results showed that the PbO2 coating was composed of anα-PbO2 inner layer and aβ-PbO2 outer layer.Accelerated life measurement indicated that the composite electrode had a lifetime of 815 h.Rhodamine B(RhB)was employed as a model pollutant to analyze the electrocatalytic activity of the electrode.The effects of initial RhB concentration,current density,initial pH,temperature,and chloride ion concentration on the electrochemical oxidation were investigated in detail.Inductively coupled plasma atomic emission spectroscopy(ICP-AES)results suggested that the concentration of leached Pb^2+in the electrolyte during the electrocatalytic oxidation process can be neglected.Finally,the degradation mechanism during the electrocatalytic oxidation process was proposed based on the results of solid-phase micro-extraction-gas chromatography-mass spectrometry(SPME-GC-MS).The high electrocatalytic performance of the composite electrode makes it a promising anode for the treatment of organic pollutants in aqueous solution.展开更多
Two novel rhodamine-based fluorescence enhanced molecular probes （RA1 and RA2） were synthesized, which were both designed as comparative fiuoroionophore and chromophore for the optical detection of Hg^2＋. The recog...Two novel rhodamine-based fluorescence enhanced molecular probes （RA1 and RA2） were synthesized, which were both designed as comparative fiuoroionophore and chromophore for the optical detection of Hg^2＋. The recognizing behaviors were investigated both experimentally and computationally. They exhibited high selectivity and sensitivity for Hg^2＋ over other commonly coexistent metal ions in CH3CN/H2O （1：1, V/V） solution. Test shows that hydroxy benzene of rich electron was beneficial to the chelate of Hg^2＋ with sensors. The detection limit was measured to be at least 0.14 p.mol/L. After addition of Hg^2＋, the color changed from colourless to pink, which was easily and hydrogel sensor. detected by the naked eye in both solution展开更多
Microporous titanium dioxide films were prepared by the sol-gel methods on glass substrates, using tetrabutyl titanate as source material. In order to absorb the visible light and increase the photocatalytic activitie...Microporous titanium dioxide films were prepared by the sol-gel methods on glass substrates, using tetrabutyl titanate as source material. In order to absorb the visible light and increase the photocatalytic activities, different concentrations of neodymium ions (Nd/Ti molar ratio was 0.5%, 0.7%, 0.9%, and 1.1% respectively) were added into the sol. X-ray diffraction (XRD), X-ray photoelectron spectros-copy (XPS), and atom force microscopy (AFM) were applied to characterize the modified films. A kind of typical textile industry pollutant (Rhodamine B) was used to evaluate the photocatalytic activities of the films under visible light. The results showed that the activities of the films were improved by doping Nd ions into the sol.展开更多
Iron(II) tetra-(1,4-dithin)-porphyrazine, (FePz(dtn)4) is able to activate molecule oxygen for oxygenation degradation of rhodamine B (RhB) in an extensive pH region without light excitation. Experiments indicate that...Iron(II) tetra-(1,4-dithin)-porphyrazine, (FePz(dtn)4) is able to activate molecule oxygen for oxygenation degradation of rhodamine B (RhB) in an extensive pH region without light excitation. Experiments indicate that the RhB can be degraded nearly 52% in alkaline aqueous solution, bubbling with dioxygen for seven hours in the presence of FePz(dtn)4 and the hydrogen peroxides as an active intermediate were determined by DPD method. The catalyst is recyclable and the catalyst activity was maintained after 10 recycles.展开更多
The photocatalytic degradation of dye Rhodamine B （RhB） in the presence of TiO2 nanostdpe or P25 under visible light irradiation was investigated. The degradation intermediates were identified using Infrared spectra...The photocatalytic degradation of dye Rhodamine B （RhB） in the presence of TiO2 nanostdpe or P25 under visible light irradiation was investigated. The degradation intermediates were identified using Infrared spectra （IR spectra）, ^1H nuclear magnetic resonance （^1HNMR） spectra, and gas chromatography-mass spectroscopy （GC-MS）. The IR and the ^1HNMR results showed that the large conjugated chromophore structure of RhB was efficiently destroyed under visible light irradiation in both the photocatalytic systems （TiO2 nanostfipe or P25 and Rhodamine B systems）. GC-MS results showed that the main identified intermediates were ethanediotic acid, 1,2-benzenedicarboxylic acid, 4-hydroxy benzoic acid and benzoic acid, which were almost the same in the TiO2 nanostdpes and P25 systems. This work provides a good insight into the reaction pathway（s） for the TiO2-assisted photocatalytic degradation of dye pollutants under visible light irradiation.展开更多
The recognition interaction of Rhodamine B(RB) with DNA was studied in a Britton-Robinson (B-R) buffer solution with pH=7.5 at a glassy carbon electrode by electrochemical techniques. RB shows an irreversible oxidatio...The recognition interaction of Rhodamine B(RB) with DNA was studied in a Britton-Robinson (B-R) buffer solution with pH=7.5 at a glassy carbon electrode by electrochemical techniques. RB shows an irreversible oxidation peak at +0.92 V(vs. SCE). After the addition of DNA in the RB solution, the peak current of RB decreased apparently without the shift of the peak potential. The electrochemical parameters such as the charge transfer coefficient α and the electrode reaction rate constant k s of the interaction system were carefully studied. The parameters did not change before and after the addition of DNA, which indicated that an electrochemical non-active complex had been formed, so the concentration of RB in the solution decreased and the peak current decreased correspondingly. The binding ratio of RB to DNA was 2∶1 with a binding constant of 2.66×10 9.展开更多
文摘A simple two-step hydrothermal method synthesized four different CdS/Fe_(3)O_(4)photocatalysts with varying ratios of mass of CdS to Fe_(3)O_(4).The composition and morphology of the prepared samples were investigated using X-ray diffraction(XRD),Raman spectrum,X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),and transmission electron microscopy(TEM).Solid UV reflectance spectra testing found that CdS/Fe_(3)O_(4)nanocomposites had good light absorption throughout the spectral range,promoting their photocatalytic properties.Under visible light irradiation,CdS/Fe_(3)O_(4)(2∶5)with a mass ratio of 2∶5 exhibited excellent photocatalytic perfor-mance,with a degradation rate of 98.8%for rhodamine B.Furthermore,after five cycles of photocatalytic degrada-tion reaction,the rhodamine B degradation rate remained at 96.2%,indicating that the photocatalysts have good pho-tocatalytic stability.
基金Funded by Guizhou Provincial Natural Science Foundation(No.[2020]1Y030)Young Science and Technology Talents of Education Department of Guizhou Province(No.KY[2016]136)+1 种基金Doctoral Start-up Fund by Guizhou Normal University in 2014,The Guizhou Province Science and Technology Planning Project(No.[2016]1100)National Natural Science Foundation of China(No.21764004)。
文摘We investigated the removal of the organic dye rhodamine B in wastewater with recyclable AgBr/polypyrrole(PPy)nano-photocatalysts.With PPy as an active base for electron transfer,and hexadecyltrimethylammonium bromide(CTAB)as both the soft-templating agent and the bromine source,a series of AgBr/PPy nano-photocatalysts containing various proportions of silver were prepared in a convenient one-step synthesis procedure.The synthesized catalysts were characterized by TG analysis to reveal that,in comparison with pure PPy,the interaction between PPy and AgBr led to increased thermal stability.Chemical combination of PPy and AgBr was observed through XRD and XPS analyses.For the morphology study,the AgBr particles were found to be well dispersed in the PPy nanowire network from SEM results.In the photodegradation experiments,up to 92%rhodamine B was degraded by the AgBr/PPy catalysts in the period of 1 hour under 254 nm UV light.The catalysts could maintain 60%catalytic efficiency after 3 cycles in the recyclability test.
文摘A plasmonic effect of silver nanoparticles (AgNPs) in dye-sensitized solar cells (DSSCs) is studied. In this investigation, the efficiency of dye-sensitized solar cells has been remarkably increased by infusion of synthesized silver nanoparticles into the TiO<sub>2</sub> photoanode. Rhodaminederivative RdS1 was synthesized by microwave-assisted condensation of hydrazide and 3-for-mylchromone. The synthesized silver nanoparticles were characterized with UV/Vis absorption spectroscopy and transmission electron microscopy. The interfacial charge transport phenomena of the dye-sensitized solar cell (DSSCs) are determined by electrochemical impedance spectroscopy and the corresponding efficiencies are calculated using current-voltage (I-V) curve. The solar cell photoanode with silver nanoparticles infused with RdS1 in titanium dioxide had the highest solar-to-electric power efficiency at 0.17%.
文摘The present work deals on one hand with the valorization of wastes plastics, polyethylene terephthalate (PET) and Canarium schweinfurthii (CS) for the preparation of polyethylene terephthalate activated carbon (PETAC) and Canarium schweinfurthii/polyethylene terephthalate activated carbon (CS/PETAC). These adsorbents, on the other hand, were used for removal Rhodamine B (RhB) in an aqueous solution. PET and CS precursors were subjected to thermogravimetric analysis (TGA) and differential scanning colorimetry (DSC). Meanwhile PETAC and CS/PETAC were characterized using scanning electron microscopy-energy dispersive spectrometry (SEM-EDS), X-ray fluorescence (XRF), Fourier transformed infrared spectroscopy (FT-IR) and nitrogen adsorption/desorption (N<sub>2</sub>-BET). The N<sub>2</sub>-BET results revealed an increase of the specific surface area from 6.75 m<sup>2</sup>/g to 1282.0 m<sup>2</sup>/g for PETAC and CS/PETAC. The results of characterization indicated the key role played by plastic wastes to enhance the structural and functional properties of CS/PETAC. The RhB removal from the aqueous solution onto PETAC and CS/PETAC was found to be independent of pH, with an optimal contact time of RhB removal within 10 min for materials. The non-linear adsorption isotherm data for the adsorption process showed that the Langmuir and Freundlich models best fitted the RhB adsorption onto PETAC meanwhile only the Freundlich adsorption isotherm gave the best fit for CS/PETAC according to the correlation coefficient value closed to unity. The pseudo-first and pseudo-second-order kinetic models best described the RhB dye removal on both adsorbents. Additionally, the Elovich model confirmed that chemisorption was the main mechanism followed. These findings proved that CS seeds and PET wastes are low-cost precursors that should be given an added value by transforming them into an outstanding carbon material for dye removal in liquid effluent.
基金supported by the National Natural Science Foundation of China (21573101)the Liaoning Provincial Natural Science Foundation(2014020107)+2 种基金the Program for Liaoning Excellent Talents in University (LJQ2014041)the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry ([2013]1792)the Opening Project of Key Laboratory of Photochemical Conversion and Optoelectronic Materials, TIPC, CAS,the Opening Project of State Key Laboratory of Catalysis, DICP, CAS (N-09-06)~~
文摘A series of WO3 samples with different crystalline phases were prepared by the thermal decomposition method from ammonium tungstate hydrate.X-ray diffraction（XRD）,scanning electron microscopy（SEM）,high-resolution transmission electron microscopy（HRTEM）,X-ray photoelectron spectroscopy,and N2 adsorption-desorption were used to characterize the crystalline phase,morphology,particle size,chemical composition,and surface area of the WO3 samples.The formation of hexagonal（h-WO3） and monoclinic（m-WO3） crystal structures of WO3 at different temperatures or different times was confirmed by XRD.m-WO3 is formed at 600 ℃,while m-WO3 starts to transform into h-WO3 at 800℃.However,h-WO3,which forms at 800℃,may transform into m-WO3 by increasing the calcination temperature to 1000℃.SEM results indicate that m-WO3 particles exhibit a bulky shape with heavy aggregates,while h-WO3 particles exhibit a rod-like shape.Moreover,m-WO3 crystals are sporadically patched on the surface of the h-WO3 rod-like particles,resulting in the exposure of both m-WO3 and h-WO3 on the surface.It is observed that the monoclinic phase（m-WO3）/hexagonal phase（h-WO3） junction was fabricated by tuning the calcination temperature and calcination time.The relative ratios between m-WO3 and h-WO3 in the phase junction can readily be tailored by control of the calcination time.The photocatalytic activities of WO3 with different crystalline phases were evaluated by the photocatalytic degradation of rhodamine B as a model pollutant.A higher photocatalytic activity was observed in the WO3 sample with the m-WO3/h-WO3junction as compared with the sample with only m-WO3.The improvement of photocatalytic activity can be attributed to the reduction of the electron-hole recombination rate owing to the formation of the phase junction,whose presence has been confirmed by HRTEM and photoluminescence spectra.
文摘Polarization variable-angle synchronous fluorescence spectrometry was proposed to determine samples in turbid solution. A mixture of fluorescein, rhodamine 6G and rhodamine B was used to evaluate the technique. The background caused by scattering light was decreased remarkably. The limits of detection were 0.6 ng/ml for fluorescein, 2.3 ng/ml for rhodamine 6G and 4.1 ng/ml for rhodamine B, respectively.
基金supported by the National Natural Science Foundation of China(21003033,21203047)Guangxi Natural Science Foundation,China(2014GXNSFAA118019)+1 种基金Research Foundation of Education Bureau of Guangxi,China(ZD2014127)Doctor's Scientific Research Foundation of Hezhou University,China(HZUBS201401)~~
文摘In acid medium, rhodamine B（RhB）, rhodamine S（RhS）, rhodamine 6G（RhG） and butyl rhodamine B（b-RhB） have a fluorescence peak at 580, 549, 553 and 580nm, respectively. BrO^-3 oxidizes excess I^- into I^-3 Rhodamine dyes combine I^-3 to form ion association nanoparticles, resulting in fluorescence quenching at 580, 549, 553 and 580 rim, respectively. The fluorescence quenching intensity is proportional to the concentration of BrO^-3 in the range of 0.020 4 - 0.710 μg/mL for RhB, 0.025 - 0. 512μg/mL for RhS, 0.025 - 0.260 μg/mL for RhG, 0.025 - 1.28μg/mL for b-RhB, respectively. In the four systems, RhB system has good stability and high sensitivity. Thus, a simple, sensitive fluorescence method was proposed for the determination of BrO^-3 in commercial bread additives and flours, with satisfactory results. The results of the fluorescence spectra and scan electron microscopy show that the formation of about 60 ran （RhB - I^-3） n association nanoparticles and the interface between the nanoparticles and solution are main factors that cause the fluorescence quenching.
基金This work was supported by the National Basic Research Program of China （No.2010CB923300）, the National Natural Science Foundation of China （No.91127042 and No.21173205）, the Chinese Academy of Sciences （No.XDB01020000）, the FR- FCUC （No.WK2340000012）, the USTC-NSRL Joint Funds （No.KY2340000021）, and the National Under- graduate Innovative Training Program of Ministry of Education （No.201210358064）.
文摘We investigate the fluorescence quenching of Rhodamine 6G （R6G）, a well known laser dye with a high fluorescence quantum yield, by as-synthesized graphene oxide （GO） in aqueous solution, which is found to be rather efficient. By means of steady-state and time-resolved fluorescence spectroscopy combined with detailed analysis about the linear absorption vari- ation for this R6G-GO system, the pertinent quenching mechanism has been elucidated to be a combination of dynamic and static quenching. Possible ground-state complexes be- tween R6G and GO during the static quenching have also been suggested. Furthermore, the direction of photoindueed electron transfer between R6G and GO has been discussed.
基金supported by the National Natural Science Foundation of China (No. 20707009)the Jiangsu Province Social Development Foundation (No.BS2007051)+1 种基金the Opening Foundation (WTWER0713) of Engineering Research Center for Water Treatment and Water Remediation of the Ministry of Education of Chinathe State Key Laboratory of Pollution Control and Resource Reuse Opening Foundation (No. PCRRCF07003).
文摘The photocatalytic degradation of Rhodamine B （RhB） was carried out using TiO2 supported on activated carbon （TiO2-AC） under microwave irradiation. Composite catalyst TiO2-AC was prepared and characterized using X-ray diffraction （XRD）, transmission electron microscopy （TEM） and Brunauer-Emmett-Teller （BET）. In the process of microwave-enhanced photocatalysis （MPC）, RhB （30 mg/L） was almost completely decoloured in 10 min, and the mineralization efficiency was 96.0% in 20 min. The reaction rate constant of RhB in MPC using TiO2-AC by pseudo first-order reaction kinetics was 4.16 times of that using Degussa P25. Additionally, according to gas chromatography/mass spectrometry （GC/MS） and liquid chromatography/mass spectrometry （LC/MS） identification, the major intermediates of RhB in MPC included two kinds of N-de-ethylation intermediates （N,N-diethyl-N＇-ethyl-rhodamine （DER））, oxalic acid, malonic acid, snccinic acid, and phthalic acid, maleic acid, 3-nitrobenzoic acid, and so on. The degradation of RhB in MPC was mainly attributed to the destruction of the conjugated structure, and then the intermediates transformed to acid molecules which were mineralized to water and carbon dioxide.
基金supported by the National Natural Science Foundation of China(21507104)Natural Science Basic Research Plan in Shaanxi Province of China(2017JM2015)~~
文摘A PbO2/Sb-SnO2/TiO2 nanotube array composite electrode was successfully synthesized and its electrochemical oxidation properties were investigated.Field-emission scanning electron microscopy(FE-SEM)and X-ray diffraction(XRD)results showed that the PbO2 coating was composed of anα-PbO2 inner layer and aβ-PbO2 outer layer.Accelerated life measurement indicated that the composite electrode had a lifetime of 815 h.Rhodamine B(RhB)was employed as a model pollutant to analyze the electrocatalytic activity of the electrode.The effects of initial RhB concentration,current density,initial pH,temperature,and chloride ion concentration on the electrochemical oxidation were investigated in detail.Inductively coupled plasma atomic emission spectroscopy(ICP-AES)results suggested that the concentration of leached Pb^2+in the electrolyte during the electrocatalytic oxidation process can be neglected.Finally,the degradation mechanism during the electrocatalytic oxidation process was proposed based on the results of solid-phase micro-extraction-gas chromatography-mass spectrometry(SPME-GC-MS).The high electrocatalytic performance of the composite electrode makes it a promising anode for the treatment of organic pollutants in aqueous solution.
文摘Two novel rhodamine-based fluorescence enhanced molecular probes （RA1 and RA2） were synthesized, which were both designed as comparative fiuoroionophore and chromophore for the optical detection of Hg^2＋. The recognizing behaviors were investigated both experimentally and computationally. They exhibited high selectivity and sensitivity for Hg^2＋ over other commonly coexistent metal ions in CH3CN/H2O （1：1, V/V） solution. Test shows that hydroxy benzene of rich electron was beneficial to the chelate of Hg^2＋ with sensors. The detection limit was measured to be at least 0.14 p.mol/L. After addition of Hg^2＋, the color changed from colourless to pink, which was easily and hydrogel sensor. detected by the naked eye in both solution
基金Project supported by the State Key Laboratory of Urban Water Resource and Environment (HIT 08UWQA05) and National Key Laboratory of Vacuum and Cryogenics Technology and Physics (9140C550201060C55)
文摘Microporous titanium dioxide films were prepared by the sol-gel methods on glass substrates, using tetrabutyl titanate as source material. In order to absorb the visible light and increase the photocatalytic activities, different concentrations of neodymium ions (Nd/Ti molar ratio was 0.5%, 0.7%, 0.9%, and 1.1% respectively) were added into the sol. X-ray diffraction (XRD), X-ray photoelectron spectros-copy (XPS), and atom force microscopy (AFM) were applied to characterize the modified films. A kind of typical textile industry pollutant (Rhodamine B) was used to evaluate the photocatalytic activities of the films under visible light. The results showed that the activities of the films were improved by doping Nd ions into the sol.
文摘Iron(II) tetra-(1,4-dithin)-porphyrazine, (FePz(dtn)4) is able to activate molecule oxygen for oxygenation degradation of rhodamine B (RhB) in an extensive pH region without light excitation. Experiments indicate that the RhB can be degraded nearly 52% in alkaline aqueous solution, bubbling with dioxygen for seven hours in the presence of FePz(dtn)4 and the hydrogen peroxides as an active intermediate were determined by DPD method. The catalyst is recyclable and the catalyst activity was maintained after 10 recycles.
基金Project supported by the National Natural Science Foundation of China(No. 20567002)the Scientific Research Startup Foundation of InnerMongolia University (No. 203044)+2 种基金the Education Department of InnerMongolia Autonomous Region (No. NJ04093, NJ03121)the ChunhuiPlan of the Education Ministry (No. Z2004-2-15030)the "513 TalentsPlan" of Inner Mongolia University.
文摘The photocatalytic degradation of dye Rhodamine B （RhB） in the presence of TiO2 nanostdpe or P25 under visible light irradiation was investigated. The degradation intermediates were identified using Infrared spectra （IR spectra）, ^1H nuclear magnetic resonance （^1HNMR） spectra, and gas chromatography-mass spectroscopy （GC-MS）. The IR and the ^1HNMR results showed that the large conjugated chromophore structure of RhB was efficiently destroyed under visible light irradiation in both the photocatalytic systems （TiO2 nanostfipe or P25 and Rhodamine B systems）. GC-MS results showed that the main identified intermediates were ethanediotic acid, 1,2-benzenedicarboxylic acid, 4-hydroxy benzoic acid and benzoic acid, which were almost the same in the TiO2 nanostdpes and P25 systems. This work provides a good insight into the reaction pathway（s） for the TiO2-assisted photocatalytic degradation of dye pollutants under visible light irradiation.
文摘The recognition interaction of Rhodamine B(RB) with DNA was studied in a Britton-Robinson (B-R) buffer solution with pH=7.5 at a glassy carbon electrode by electrochemical techniques. RB shows an irreversible oxidation peak at +0.92 V(vs. SCE). After the addition of DNA in the RB solution, the peak current of RB decreased apparently without the shift of the peak potential. The electrochemical parameters such as the charge transfer coefficient α and the electrode reaction rate constant k s of the interaction system were carefully studied. The parameters did not change before and after the addition of DNA, which indicated that an electrochemical non-active complex had been formed, so the concentration of RB in the solution decreased and the peak current decreased correspondingly. The binding ratio of RB to DNA was 2∶1 with a binding constant of 2.66×10 9.
