A novel 1-methylimidazole ionic liquid modified SBA15 mesoporous silica(1-MIIL@SBA15) was synthesized and applied to selective separation of inorganic arsenic(iAs) in rice by dispersive solid phase extraction(DSPE), f...A novel 1-methylimidazole ionic liquid modified SBA15 mesoporous silica(1-MIIL@SBA15) was synthesized and applied to selective separation of inorganic arsenic(iAs) in rice by dispersive solid phase extraction(DSPE), followed by hydride generation-atomic fluorescence spectrometric(HG-AFS) quantification. The prepared sorbent was characterized by FTIR, FESEM, BET and Zeta potential. Key parameters of adsorption and desorption in DSPE were optimized using standard reference material 1568 b rice flour. Under optimal conditions, the limit of detection was 8.776 ng/kg, relative standard deviation was ≤2.0%, and recoveries of iAs were in the 92.3～94.4% range. This method was successfully applied to the determination of iAs in rice. Under acidic condition, the electrostatic interaction between the positively charged 1-MIIL@SBA15 and anionic iAs played an important role in selective iAs separation, rendering this method suitable for iAs analysis.展开更多
A novel PEO-based composite polymer electro-lyte by using organic-inorganic hybrid EO20PO70EO20-em- mesoporous silica (P123-em-SBA15) as the filler has been developed. The experiment results show that P123-em- SBA15 c...A novel PEO-based composite polymer electro-lyte by using organic-inorganic hybrid EO20PO70EO20-em- mesoporous silica (P123-em-SBA15) as the filler has been developed. The experiment results show that P123-em- SBA15 can enhance the lithium-ion transference number of the composite polymer electrolyte, which is induced by the special topology structure of P123 in P123-em-SBA15 hybrid. In addition, room temperature ionic conductivity of the composite polymer electrolyte can also be increased by about two orders of magnitude. The excellent lithium transport properties suggest that PEO-LiClO4-P123-em-SBA15 com-posite polymer electrolyte can be used as electrolyte materi-als for all solid-state rechargeable lithium polymer batteries.展开更多
A series of Sn‐incorporated SBA‐15materials with high specific surface areas and highly orderedmesoporous structures were synthesized by a facile one‐pot method and used as catalyst supports.A reference sample was ...A series of Sn‐incorporated SBA‐15materials with high specific surface areas and highly orderedmesoporous structures were synthesized by a facile one‐pot method and used as catalyst supports.A reference sample was also prepared using a conventional impregnation method.The catalystswere characterized using various methods,and their activities in propane dehydrogenation wereinvestigated.The incorporation of Sn into the SBA‐15matrix led to strong interactions between Snspecies and the support,and these helped to maintain the oxidation states of Sn species during thereaction.Substitution with Sn changed the interfacial properties of the Pt species and improved thefunction and effect of the Sn promoter.The catalytic activities and stabilities of the Pt catalysts supportedon Sn‐incorporated SBA‐15were better than those of the impregnated sample.However,thecatalytic performance deteriorated when an excessive amount of Sn was introduced and the interactionsamong Pt,Sn species,and the support became weaker.The Pt/0.5Sn‐SBA‐15catalyst gavethe best propene selectivity,i.e.,98.5%,with a corresponding propane conversion of about43.8%.展开更多
The catalytic oxidation of toluene over Ag/SBA‐15synthesized under different pretreatment conditions,including O2at500°C(denoted O500),H2at500°C(H500),and O2at500°C followed by H2at300°C(O500‐H30...The catalytic oxidation of toluene over Ag/SBA‐15synthesized under different pretreatment conditions,including O2at500°C(denoted O500),H2at500°C(H500),and O2at500°C followed by H2at300°C(O500‐H300)was studied.The pretreated samples were investigated by N2physisorption,X‐ray diffraction,and ultraviolet‐visible diffuse reflectance.The pretreatment atmosphere greatly influences the status of the Ag and O species,which in turn significantly impacts the adsorption and catalytic removal of toluene.Ag2O and amorphous Ag particles,as well as a large amount of subsurface oxygen species,are formed on O500,and the subsurface oxygen enhances the interaction between Ag species and toluene,so O500shows good activity at higher temperature.However,its activity at lower temperature is not as high as expected,with a reduced presence of Ag2O and lower adsorption capacity for toluene.H2pretreatment at500°C is conducive to the formation of large Ag particles and yields the largest adsorption capacity for toluene,so H500exhibits the best activity at lower temperatures;however,because of poor interaction between Ag and toluene,its activity at higher temperature is modest.The O500‐H300sample exhibits excellent catalytic activity during the whole reaction process,which can be attributed to the small and highly dispersed Ag nanoparticles as well as the existence of subsurface oxygen.展开更多
The active sites for hydrogenation over Ru/SBA‐15catalysts were identified using in situ Fourier‐transform infrared spectroscopy.The amount of active sites was proportional to the interfacial circumference of the Ru...The active sites for hydrogenation over Ru/SBA‐15catalysts were identified using in situ Fourier‐transform infrared spectroscopy.The amount of active sites was proportional to the interfacial circumference of the Ru particles.In contrast,the rate of hydrogen spillover from Ru to the support was inversely proportional to the size of the Ru metal particles.Consequently,a catalyst with small Ru metal particles has a high rate of hydrogen spillover but a low density of active sites,whereas one with large Ru particles has a low rate of hydrogen spillover but a high density of active sites.The formation of these active sites is probably an intermediate step in hydrogen spillover.展开更多
Nowadays, the rapid and effective detection of low doses of heavy metal pollutants in contaminated water is a timely challenge in environmental pollution research. In this study, a rapid and highly sensitive assay for...Nowadays, the rapid and effective detection of low doses of heavy metal pollutants in contaminated water is a timely challenge in environmental pollution research. In this study, a rapid and highly sensitive assay for the detection of Hg^2＋based on quenching of metal-enhanced fluorescence of rhodamine B（RB）has been fabricated. RB and silver nanoparticle were incorporated into the mesoporous siliceous framework spin cast on a quartz glass through post-synthetic incorporation method. The morphology and crystallinity of mesoporous structure and Ag nanoparticle were characterized by transmission electron microscopy and X-ray diffraction analyses. Photoluminescence assays on the hybrid thin film of RB-Ag-SBA15 showed a high enhancement when compared to the intensity of silver free SBA15-RB in the wavelength of 575 nm. The fluorescence of RB-Ag-SBA15 thin film decreased gradually with the increase in the concentration of Hg^2＋and the detection limits were 10.54 nmol/L. Furthermore, the fluorescence intensity increased linearly with the concentration of Hg^2＋in the range from 1.0 ×10^-8mol/L to10× 10^-8mol/L, with a response time of a few seconds. In addition, this system offers a high selectivity over interfering cations such as Cd^2＋ and Pb^2＋. Overall, we have developed an optical assay having a wellordered mesoporous SBA15 containing Ag-RBfor selective detection of Hg^2＋in aqueous solution. The scheme combines the advantages of specific binding interactions between Hg^2＋and RB molecule and optical emission properties of RB. The method is suitable for a single-shot and irreversible analytical assay in a quartz glass/microtiter plate.展开更多
基金Financially supported by the National Natural Science Foundation of China(No.31701708)the Outstanding Youth Foundation Project of Fujian Agriculture and Forestry University of China(No.xjq201710)
文摘A novel 1-methylimidazole ionic liquid modified SBA15 mesoporous silica(1-MIIL@SBA15) was synthesized and applied to selective separation of inorganic arsenic(iAs) in rice by dispersive solid phase extraction(DSPE), followed by hydride generation-atomic fluorescence spectrometric(HG-AFS) quantification. The prepared sorbent was characterized by FTIR, FESEM, BET and Zeta potential. Key parameters of adsorption and desorption in DSPE were optimized using standard reference material 1568 b rice flour. Under optimal conditions, the limit of detection was 8.776 ng/kg, relative standard deviation was ≤2.0%, and recoveries of iAs were in the 92.3～94.4% range. This method was successfully applied to the determination of iAs in rice. Under acidic condition, the electrostatic interaction between the positively charged 1-MIIL@SBA15 and anionic iAs played an important role in selective iAs separation, rendering this method suitable for iAs analysis.
文摘A novel PEO-based composite polymer electro-lyte by using organic-inorganic hybrid EO20PO70EO20-em- mesoporous silica (P123-em-SBA15) as the filler has been developed. The experiment results show that P123-em- SBA15 can enhance the lithium-ion transference number of the composite polymer electrolyte, which is induced by the special topology structure of P123 in P123-em-SBA15 hybrid. In addition, room temperature ionic conductivity of the composite polymer electrolyte can also be increased by about two orders of magnitude. The excellent lithium transport properties suggest that PEO-LiClO4-P123-em-SBA15 com-posite polymer electrolyte can be used as electrolyte materi-als for all solid-state rechargeable lithium polymer batteries.
基金supported by the Science & Technology Support Plan Projects of Sichuan Province (2016GZ0371)National Natural Science Foun-dation of China (NNSFC,21476145,21506111)~~
文摘A series of Sn‐incorporated SBA‐15materials with high specific surface areas and highly orderedmesoporous structures were synthesized by a facile one‐pot method and used as catalyst supports.A reference sample was also prepared using a conventional impregnation method.The catalystswere characterized using various methods,and their activities in propane dehydrogenation wereinvestigated.The incorporation of Sn into the SBA‐15matrix led to strong interactions between Snspecies and the support,and these helped to maintain the oxidation states of Sn species during thereaction.Substitution with Sn changed the interfacial properties of the Pt species and improved thefunction and effect of the Sn promoter.The catalytic activities and stabilities of the Pt catalysts supportedon Sn‐incorporated SBA‐15were better than those of the impregnated sample.However,thecatalytic performance deteriorated when an excessive amount of Sn was introduced and the interactionsamong Pt,Sn species,and the support became weaker.The Pt/0.5Sn‐SBA‐15catalyst gavethe best propene selectivity,i.e.,98.5%,with a corresponding propane conversion of about43.8%.
基金supported by the National Natural Science Foundation of China(21377016,21577014)Program for Changjiang Scholars and Innovative Research Team in University(IRT_13R05)~~
文摘The catalytic oxidation of toluene over Ag/SBA‐15synthesized under different pretreatment conditions,including O2at500°C(denoted O500),H2at500°C(H500),and O2at500°C followed by H2at300°C(O500‐H300)was studied.The pretreated samples were investigated by N2physisorption,X‐ray diffraction,and ultraviolet‐visible diffuse reflectance.The pretreatment atmosphere greatly influences the status of the Ag and O species,which in turn significantly impacts the adsorption and catalytic removal of toluene.Ag2O and amorphous Ag particles,as well as a large amount of subsurface oxygen species,are formed on O500,and the subsurface oxygen enhances the interaction between Ag species and toluene,so O500shows good activity at higher temperature.However,its activity at lower temperature is not as high as expected,with a reduced presence of Ag2O and lower adsorption capacity for toluene.H2pretreatment at500°C is conducive to the formation of large Ag particles and yields the largest adsorption capacity for toluene,so H500exhibits the best activity at lower temperatures;however,because of poor interaction between Ag and toluene,its activity at higher temperature is modest.The O500‐H300sample exhibits excellent catalytic activity during the whole reaction process,which can be attributed to the small and highly dispersed Ag nanoparticles as well as the existence of subsurface oxygen.
基金supported by the National Natural Science Foundation of China(21303163)the Natural Science Foundation of Zhejiang Province(LY13B030006,LY17B060006)+1 种基金the Qianjiang Talent Project in Zhejiang Province(QJD1302011)the Scientific Research Fund of Zhejiang Provincial Education Department(Y201328681)~~
文摘The active sites for hydrogenation over Ru/SBA‐15catalysts were identified using in situ Fourier‐transform infrared spectroscopy.The amount of active sites was proportional to the interfacial circumference of the Ru particles.In contrast,the rate of hydrogen spillover from Ru to the support was inversely proportional to the size of the Ru metal particles.Consequently,a catalyst with small Ru metal particles has a high rate of hydrogen spillover but a low density of active sites,whereas one with large Ru particles has a low rate of hydrogen spillover but a high density of active sites.The formation of these active sites is probably an intermediate step in hydrogen spillover.
基金financial support from the Department of Science and Technology,Govt of India through Fast Track Young Scientist Scheme(No.SR/FT/CS-103/2009)
文摘Nowadays, the rapid and effective detection of low doses of heavy metal pollutants in contaminated water is a timely challenge in environmental pollution research. In this study, a rapid and highly sensitive assay for the detection of Hg^2＋based on quenching of metal-enhanced fluorescence of rhodamine B（RB）has been fabricated. RB and silver nanoparticle were incorporated into the mesoporous siliceous framework spin cast on a quartz glass through post-synthetic incorporation method. The morphology and crystallinity of mesoporous structure and Ag nanoparticle were characterized by transmission electron microscopy and X-ray diffraction analyses. Photoluminescence assays on the hybrid thin film of RB-Ag-SBA15 showed a high enhancement when compared to the intensity of silver free SBA15-RB in the wavelength of 575 nm. The fluorescence of RB-Ag-SBA15 thin film decreased gradually with the increase in the concentration of Hg^2＋and the detection limits were 10.54 nmol/L. Furthermore, the fluorescence intensity increased linearly with the concentration of Hg^2＋in the range from 1.0 ×10^-8mol/L to10× 10^-8mol/L, with a response time of a few seconds. In addition, this system offers a high selectivity over interfering cations such as Cd^2＋ and Pb^2＋. Overall, we have developed an optical assay having a wellordered mesoporous SBA15 containing Ag-RBfor selective detection of Hg^2＋in aqueous solution. The scheme combines the advantages of specific binding interactions between Hg^2＋and RB molecule and optical emission properties of RB. The method is suitable for a single-shot and irreversible analytical assay in a quartz glass/microtiter plate.
