A new composite photocatalyst of modified oyster shell powder/Ce-N-TiO<sub>2</sub> was prepared by sol-gel method. Based on single factor experiment, Ce doping rate, N doping rate and calcination temperatu...A new composite photocatalyst of modified oyster shell powder/Ce-N-TiO<sub>2</sub> was prepared by sol-gel method. Based on single factor experiment, Ce doping rate, N doping rate and calcination temperature were taken as input variables. Based on the central composite design (BBD) response surface model, two functional relationship models between three independent variables and glyphosate removal rate were established to evaluate the influence degree of independent variables and interaction on catalyst. The significance of the model and regression coefficient was tested by variance analysis. The analysis of the obtained data showed that the degradation performance of the composite photocatalyst was significantly affected by the calcination temperature and the rate of N doping, while the rate of Ce doping had little effect;at the calcination temperature of 505.440°C, the degradation rate of glyphosate reached the maximum of 82.15% under the preparation conditions of 17.057 mol% N doping and 0.165 mol% Ce doping, respectively.展开更多
In order to improve the substrate diffusion properties and stability of an immobilized enzyme alginate microgels modified with TiO2 nanoparticles were employed as the enzyme immobilizing support.Ionotropic gelation wa...In order to improve the substrate diffusion properties and stability of an immobilized enzyme alginate microgels modified with TiO2 nanoparticles were employed as the enzyme immobilizing support.Ionotropic gelation was applied for the preparation of hybrid gels while Ca2＋ Ce3＋ Ni2＋Cu2＋and Fe3＋were employed as the crosslinkers.Papain was selected as the model enzyme. UV-Vis spectroscopy was employed to investigate the activity of papain to evaluate kinetics and stability.Analysis results show that the highest affinity the lowest Michaelis-Menten constant Km =11.0 mg/mL and the highest stability are obtained when using Cu2＋as the crosslinker.The effect of the mass ratio of TiO2 to papain on the stability and leakage of papain is also investigated and the results show that 10∶1 TiO2∶papain is optimal because the proper use of TiO2 can reduce enzyme leakage and ensure enzyme stability.Preparing Cu/alginate/TiO2 hybrid gels via ionotropic gelation can provide a satisfactory diffusion capability and enzyme stability.展开更多
This study aims to prepare and characterize non-metallic nitrogen-modified titanium dioxide(N-TiO_(2)),film and expand its photocatalytic excitation wavelength to the visible blue-violet region.The film uses corn star...This study aims to prepare and characterize non-metallic nitrogen-modified titanium dioxide(N-TiO_(2)),film and expand its photocatalytic excitation wavelength to the visible blue-violet region.The film uses corn starch as a carrier.It is combined with blue-violet LED light to explore the effect of this combination on the quality of Agaricus bisporus during storage.This study found that the mechanical properties and hydrophobicity of the corn starch film with nano-TiO_(2) added were improved;the effect of adding N-TiO_(2) was more pronounced;the tensile strength increased by 65%while the water contact angle increased by 11%.In the application of A.bisporus storage,the film combined with blue-violet LED light can slow down the loss of moisture,reduce the respiratory rate,delay the appearance of the respiratory peak,and maintain the color and hardness of A.bisporus.After 15 d of storage,compared to the control group,the hardness decreased by 69%,browning index(BI)increased by 221%,the CS-N group hardness decreased by only 23%,and the BI increased by 89%.Under blue-violet LED light,the accumulation of secondary metabolites in A.bisporus increased,and the polyphenol content also showed an increasing trend during storage.展开更多
文摘A new composite photocatalyst of modified oyster shell powder/Ce-N-TiO<sub>2</sub> was prepared by sol-gel method. Based on single factor experiment, Ce doping rate, N doping rate and calcination temperature were taken as input variables. Based on the central composite design (BBD) response surface model, two functional relationship models between three independent variables and glyphosate removal rate were established to evaluate the influence degree of independent variables and interaction on catalyst. The significance of the model and regression coefficient was tested by variance analysis. The analysis of the obtained data showed that the degradation performance of the composite photocatalyst was significantly affected by the calcination temperature and the rate of N doping, while the rate of Ce doping had little effect;at the calcination temperature of 505.440°C, the degradation rate of glyphosate reached the maximum of 82.15% under the preparation conditions of 17.057 mol% N doping and 0.165 mol% Ce doping, respectively.
基金The National Natural Science Foundation of China(No.21005016)the Foundation of Educational Commission of Jiangsu Province(No.JHB2011-2)
文摘In order to improve the substrate diffusion properties and stability of an immobilized enzyme alginate microgels modified with TiO2 nanoparticles were employed as the enzyme immobilizing support.Ionotropic gelation was applied for the preparation of hybrid gels while Ca2＋ Ce3＋ Ni2＋Cu2＋and Fe3＋were employed as the crosslinkers.Papain was selected as the model enzyme. UV-Vis spectroscopy was employed to investigate the activity of papain to evaluate kinetics and stability.Analysis results show that the highest affinity the lowest Michaelis-Menten constant Km =11.0 mg/mL and the highest stability are obtained when using Cu2＋as the crosslinker.The effect of the mass ratio of TiO2 to papain on the stability and leakage of papain is also investigated and the results show that 10∶1 TiO2∶papain is optimal because the proper use of TiO2 can reduce enzyme leakage and ensure enzyme stability.Preparing Cu/alginate/TiO2 hybrid gels via ionotropic gelation can provide a satisfactory diffusion capability and enzyme stability.
基金financial support from National Key R&D Program of China(No.2022YFD2100601)Jiangsu Province(China)“Collaborative Innovation Center for Food Safety and Quality Control”Industry Development Program,Jiangsu Province Key Laboratory Project of Advanced Food Manufacturing Equipment and Technology(No.FMZ202003)National First-class Discipline Program of Food Science and Technology(No.JUFSTR20180205)。
文摘This study aims to prepare and characterize non-metallic nitrogen-modified titanium dioxide(N-TiO_(2)),film and expand its photocatalytic excitation wavelength to the visible blue-violet region.The film uses corn starch as a carrier.It is combined with blue-violet LED light to explore the effect of this combination on the quality of Agaricus bisporus during storage.This study found that the mechanical properties and hydrophobicity of the corn starch film with nano-TiO_(2) added were improved;the effect of adding N-TiO_(2) was more pronounced;the tensile strength increased by 65%while the water contact angle increased by 11%.In the application of A.bisporus storage,the film combined with blue-violet LED light can slow down the loss of moisture,reduce the respiratory rate,delay the appearance of the respiratory peak,and maintain the color and hardness of A.bisporus.After 15 d of storage,compared to the control group,the hardness decreased by 69%,browning index(BI)increased by 221%,the CS-N group hardness decreased by only 23%,and the BI increased by 89%.Under blue-violet LED light,the accumulation of secondary metabolites in A.bisporus increased,and the polyphenol content also showed an increasing trend during storage.
