Azo dye cationic blue X GRL, which is non biodegradable toxic organic compound, is decolorized and subsequently mineralized by UV/H 2O 2/N 2 or UV/H 2O 2/air (O 2) system. The effects of initial solution conce...Azo dye cationic blue X GRL, which is non biodegradable toxic organic compound, is decolorized and subsequently mineralized by UV/H 2O 2/N 2 or UV/H 2O 2/air (O 2) system. The effects of initial solution concentration, initial solution pH, and some ions produced during the degradation on the rate of decolorization of cationic blue X GRL were investigated. The photodegradation of cationic blue X GRL approximately follows first order kinetics. The regression curve of the natural logarithm of concentration verus reaction time becomes less linear with initial concentration increasing. Oxygen and appropriate OH\+· generator can accelerate reaction rate. The effect of reaction atmosphere, initial concentration, light intensity on the optimal dosage of H 2O 2 were studied. It was found that the optimal H 2O 2 dosage was determined by UV light intensity. These intermediates of cationic blue X GRL decolorization are biodegradable.展开更多
Prussian blue analogue(PBA)material is a promising cathode for applications in Na-ion and K-ion batteries which can support high c-rates for charge and discharge.In this study,the material of composition[K2 CuIIFeII(C...Prussian blue analogue(PBA)material is a promising cathode for applications in Na-ion and K-ion batteries which can support high c-rates for charge and discharge.In this study,the material of composition[K2 CuIIFeII(CN)6]was synthesized and its structural and electrochemical redox behavior was investigated with 5 different alkali insertion cations(Li^+,Na^+,K^+,Rb^+,Cs^+).Galvanostatic measurements indicate that the redox potential strongly depends on the ionic radius of the inserted cation.The redox potential varies by 400 m V between using Li^+(0.79A)or Cs^+(1.73A)in the electrolyte.The underlying modification of the Fe2^+/Fe3^+redox potential in PBA is proposed to be due to the weakening of the Fe–C bond in the material.This hypothesis is supported by XRD measurements which reveal that the lattice parameter of the de-intercalated host structure follows the same trend of monotonic increase with the cation size.The relatively minor volume changes accompanying the redox(1.2%–2.4%)allow the PBA to accommodate differently sized cations,although the structural hindrances are quite pronounced at high c-rates for the larger ones(Rb^+and Cs^+).Cycle aging studies indicate that the minimum capacity fade rate is observed in case of K^+ and Rb^+ containing electrolyte.The peak intensity corresponding to the[220]crystallographic plane varies depending on the state of charge of PBA,since this plane contains the insertion cations.Owing to the sensitivity of the redox potential to the insertion cation coupled with the observed fast ion-exchange ability,the PBA material may find additional analytical applications such as ion sensing or filtration devices.展开更多
The best conditions for synthesis of starch hydroxypropyl sulphate as per the dry method were firstly established. This was done through a thorough investigation into factors affecting the synthesis including concentr...The best conditions for synthesis of starch hydroxypropyl sulphate as per the dry method were firstly established. This was done through a thorough investigation into factors affecting the synthesis including concentrations of both the NaOH catalyst and the 2-hydroxy-3-chloropropyl sulphate along with duration and temperature of the reaction. The resultant newly synthesized 2-hydroxy-3-chloropropyl sulphate was then reacted with starch to obtain starch hydroxypropyl sulphate ultimately. After being characterized by making use of IR spectroscopy analysis and scanning electronic microscope, the starch hydroxypropyl sulphate samples were submitted to evaluation for cationic dye removal using Methylene Blue (MB). Cationic dye removal was studied under a variety of conditions. Factors involved encompass initial dye concentration, duration, sulphur %, pH and adsorbent dose. 100% dye removal could be achieved under certain conditions which were described in the text.展开更多
文摘Azo dye cationic blue X GRL, which is non biodegradable toxic organic compound, is decolorized and subsequently mineralized by UV/H 2O 2/N 2 or UV/H 2O 2/air (O 2) system. The effects of initial solution concentration, initial solution pH, and some ions produced during the degradation on the rate of decolorization of cationic blue X GRL were investigated. The photodegradation of cationic blue X GRL approximately follows first order kinetics. The regression curve of the natural logarithm of concentration verus reaction time becomes less linear with initial concentration increasing. Oxygen and appropriate OH\+· generator can accelerate reaction rate. The effect of reaction atmosphere, initial concentration, light intensity on the optimal dosage of H 2O 2 were studied. It was found that the optimal H 2O 2 dosage was determined by UV light intensity. These intermediates of cationic blue X GRL decolorization are biodegradable.
基金“Le Studium Loire Valley Institute for Advanced Studies” for financial and logistical support to the researchers involved in this study“Region Centre” for financial support under the “Lavoisier” program
文摘Prussian blue analogue(PBA)material is a promising cathode for applications in Na-ion and K-ion batteries which can support high c-rates for charge and discharge.In this study,the material of composition[K2 CuIIFeII(CN)6]was synthesized and its structural and electrochemical redox behavior was investigated with 5 different alkali insertion cations(Li^+,Na^+,K^+,Rb^+,Cs^+).Galvanostatic measurements indicate that the redox potential strongly depends on the ionic radius of the inserted cation.The redox potential varies by 400 m V between using Li^+(0.79A)or Cs^+(1.73A)in the electrolyte.The underlying modification of the Fe2^+/Fe3^+redox potential in PBA is proposed to be due to the weakening of the Fe–C bond in the material.This hypothesis is supported by XRD measurements which reveal that the lattice parameter of the de-intercalated host structure follows the same trend of monotonic increase with the cation size.The relatively minor volume changes accompanying the redox(1.2%–2.4%)allow the PBA to accommodate differently sized cations,although the structural hindrances are quite pronounced at high c-rates for the larger ones(Rb^+and Cs^+).Cycle aging studies indicate that the minimum capacity fade rate is observed in case of K^+ and Rb^+ containing electrolyte.The peak intensity corresponding to the[220]crystallographic plane varies depending on the state of charge of PBA,since this plane contains the insertion cations.Owing to the sensitivity of the redox potential to the insertion cation coupled with the observed fast ion-exchange ability,the PBA material may find additional analytical applications such as ion sensing or filtration devices.
文摘The best conditions for synthesis of starch hydroxypropyl sulphate as per the dry method were firstly established. This was done through a thorough investigation into factors affecting the synthesis including concentrations of both the NaOH catalyst and the 2-hydroxy-3-chloropropyl sulphate along with duration and temperature of the reaction. The resultant newly synthesized 2-hydroxy-3-chloropropyl sulphate was then reacted with starch to obtain starch hydroxypropyl sulphate ultimately. After being characterized by making use of IR spectroscopy analysis and scanning electronic microscope, the starch hydroxypropyl sulphate samples were submitted to evaluation for cationic dye removal using Methylene Blue (MB). Cationic dye removal was studied under a variety of conditions. Factors involved encompass initial dye concentration, duration, sulphur %, pH and adsorbent dose. 100% dye removal could be achieved under certain conditions which were described in the text.
