Exploiting highly active and non-noble metal bifunctional catalysts at large current density is significant for the advancement of water electrolysis.In this work,CeO_(2)electronically structure modulated FeNi bimetal...Exploiting highly active and non-noble metal bifunctional catalysts at large current density is significant for the advancement of water electrolysis.In this work,CeO_(2)electronically structure modulated FeNi bimetallic composite porous nanosheets in-situ grown on nickel foam(NiFe_(2)O_(4)-Fe_(24)N_(10)-CeO_(2)/NF)is synthesized.Electrochemical experiments show that the NiFe_(2)O_(4)-Fe_(24)N_(10)-CeO_(2)/NF exhibited the outstanding activities toward both oxygen and hydrogen evolution reactions(OER and HER)(η1000=352 mV andη1000=429 mV,respectively).When assembled into a two-electrode system for overall water splitting(OWS),it only needs a low cell voltage of 1.81 V to drive 100 mA·cm^(-2).And it can operate stably at±500 mA·cm^(-2)over 30 h toward OER,HER and OWS without significant activity changes.The reason could be assigned to the electronic modulating of CeO_(2)on FeNi composite,which can boost the intrinsic activity and optimize the adsorption of reaction intermediates.Moreover,the porous nanosheets insitu grown on NF could enhance the contact of active site with electrolyte and facilitate the gas release,thus improving its chemical and mechanical stabilities.This study highlights a novel approach to design bifunctional non-noble metal catalysts for water splitting at large current density.展开更多
A simple, fast, precise and eco-friendly method, based on ion chromatography （IC） with a suppressed conductivity detector, was proposed for the determination of benzoic acid （BA） in milk in this paper. The chromat...A simple, fast, precise and eco-friendly method, based on ion chromatography （IC） with a suppressed conductivity detector, was proposed for the determination of benzoic acid （BA） in milk in this paper. The chromatographic separation was accomplished by using an anion exchange column eluted with 3.2 mmol/L aqueous Na2C03 and 1.0 mmol/L aqueous NaHCO3 at a flow-rate of 0.7 mL/min. The method validation experiment provided excellent results with respect to linearity （correlation coefficient up to 0.9997）, limit of detection （0.1 ug/L）, recovery values （ranging from 88.0% to 93.0%） and relative standard deviation （RSD） （below 2.2%, n = 7）.展开更多
In this work, a new sample pretreatment method prior to HPLC separations was developed for the determination of auxins in plant samples, Owing to its large surface area and high adsorption capacity, multi-walled carbo...In this work, a new sample pretreatment method prior to HPLC separations was developed for the determination of auxins in plant samples, Owing to its large surface area and high adsorption capacity, multi-walled carbon nanotube （MWCNT） was chosen as the adsorbent for the extraction of auxins from plant samples. In this study, two important auxins were selected as model analytes, namely indole-3- butyric acid （IBA） and 1-naphthylacetic acid （NAA）. They could be extracted and concentrated due to their π-π stacking interactions with MWCNT. Then HPLC-UV was introduced to detect IBA and NAA after sample pretreatment. Factors that may affect the enrichment efficiency were investigated and optimized. Comparative studies showed that MWCNT was superior to CI 8 for the extraction of the two analytes. Validation experiments showed that the optimized method had good linearity （0.9998 and 0.9960）, high recovery （81.4%-85.4%）, and low detection limits （0.0030 mg/L and 0.0012 mg/L）. The results indicated that the novel method had advantages of convenience, good sensitivity, high efficiency, and it was feasible for the determination of auxins in plant samples.展开更多
Aspartame is a widely used sweetener, the long-term safety of which has been controversial ever since it was accepted for human consumption. It is unstable and can produce some harmful degradation products under certa...Aspartame is a widely used sweetener, the long-term safety of which has been controversial ever since it was accepted for human consumption. It is unstable and can produce some harmful degradation products under certain storage conditions. A high-performance liquid chromatography/tandem mass spectrometry method was developed for the simultaneous analysis of aspartame and its four degradation products, including aspartic acid, phenylalanine, aspartyl-phenylalanine and 5-benzyl-3,6- dioxo-2-piperazieacetic acid in water and in diet soft drinks. Aspartame and its four degradation products were quantified by a matrix matched external standard calibration curve with excellent correlation coefficients. The limits of detection were 0.16-5.8 μg/L, which exhibited higher sensitivity than common methods. This method was rapid, sensitive, specific and capable of eliminating matrix interferences. It was also applied to the study of the degradation of aspartame at various pH and temperatures. The results indicated that aspartame was partly degraded under strong acidic or basic conditions and the extent of degradation increased with increasing temperature.展开更多
基金supported by the National Natural Science Foundation of China(22162004)the Natural Science Foundation of Guangxi Province(2022JJD120011).
文摘Exploiting highly active and non-noble metal bifunctional catalysts at large current density is significant for the advancement of water electrolysis.In this work,CeO_(2)electronically structure modulated FeNi bimetallic composite porous nanosheets in-situ grown on nickel foam(NiFe_(2)O_(4)-Fe_(24)N_(10)-CeO_(2)/NF)is synthesized.Electrochemical experiments show that the NiFe_(2)O_(4)-Fe_(24)N_(10)-CeO_(2)/NF exhibited the outstanding activities toward both oxygen and hydrogen evolution reactions(OER and HER)(η1000=352 mV andη1000=429 mV,respectively).When assembled into a two-electrode system for overall water splitting(OWS),it only needs a low cell voltage of 1.81 V to drive 100 mA·cm^(-2).And it can operate stably at±500 mA·cm^(-2)over 30 h toward OER,HER and OWS without significant activity changes.The reason could be assigned to the electronic modulating of CeO_(2)on FeNi composite,which can boost the intrinsic activity and optimize the adsorption of reaction intermediates.Moreover,the porous nanosheets insitu grown on NF could enhance the contact of active site with electrolyte and facilitate the gas release,thus improving its chemical and mechanical stabilities.This study highlights a novel approach to design bifunctional non-noble metal catalysts for water splitting at large current density.
基金supported by the National Natural Science Fundation of China(Nos.20975056 and 81102411)Natural Science Fundation of Shandong(Nos.ZR2011BZ004 and ZR2011BQ005)+1 种基金JSPS and NSFC under the Japan-China Scientific Cooperation Programme(No.21111140014)the Taishan Scholar Programme of Shandong Province(No.TS20070711),China
文摘A simple, fast, precise and eco-friendly method, based on ion chromatography （IC） with a suppressed conductivity detector, was proposed for the determination of benzoic acid （BA） in milk in this paper. The chromatographic separation was accomplished by using an anion exchange column eluted with 3.2 mmol/L aqueous Na2C03 and 1.0 mmol/L aqueous NaHCO3 at a flow-rate of 0.7 mL/min. The method validation experiment provided excellent results with respect to linearity （correlation coefficient up to 0.9997）, limit of detection （0.1 ug/L）, recovery values （ranging from 88.0% to 93.0%） and relative standard deviation （RSD） （below 2.2%, n = 7）.
基金supported by National Natural Science Foundation of China(Nos.20975056,21275082 and 81102411)Natural Science Foundation of Shandong(Nos. ZR2011BZ004,ZR2011BQ005)+2 种基金JSPS and NSFC under the Japan-China Scientific Cooperation Program(No.21111140014)State Key Laboratory of Analytical Chemistry for Life Science(No. SKLACLS1110)the National Key Basic Research Development Program of China(973 Special Preliminary Study Plan,No. 2012CB722705)
文摘In this work, a new sample pretreatment method prior to HPLC separations was developed for the determination of auxins in plant samples, Owing to its large surface area and high adsorption capacity, multi-walled carbon nanotube （MWCNT） was chosen as the adsorbent for the extraction of auxins from plant samples. In this study, two important auxins were selected as model analytes, namely indole-3- butyric acid （IBA） and 1-naphthylacetic acid （NAA）. They could be extracted and concentrated due to their π-π stacking interactions with MWCNT. Then HPLC-UV was introduced to detect IBA and NAA after sample pretreatment. Factors that may affect the enrichment efficiency were investigated and optimized. Comparative studies showed that MWCNT was superior to CI 8 for the extraction of the two analytes. Validation experiments showed that the optimized method had good linearity （0.9998 and 0.9960）, high recovery （81.4%-85.4%）, and low detection limits （0.0030 mg/L and 0.0012 mg/L）. The results indicated that the novel method had advantages of convenience, good sensitivity, high efficiency, and it was feasible for the determination of auxins in plant samples.
基金supported by the National Nature Science Foundation of China (No.21075074)
文摘Aspartame is a widely used sweetener, the long-term safety of which has been controversial ever since it was accepted for human consumption. It is unstable and can produce some harmful degradation products under certain storage conditions. A high-performance liquid chromatography/tandem mass spectrometry method was developed for the simultaneous analysis of aspartame and its four degradation products, including aspartic acid, phenylalanine, aspartyl-phenylalanine and 5-benzyl-3,6- dioxo-2-piperazieacetic acid in water and in diet soft drinks. Aspartame and its four degradation products were quantified by a matrix matched external standard calibration curve with excellent correlation coefficients. The limits of detection were 0.16-5.8 μg/L, which exhibited higher sensitivity than common methods. This method was rapid, sensitive, specific and capable of eliminating matrix interferences. It was also applied to the study of the degradation of aspartame at various pH and temperatures. The results indicated that aspartame was partly degraded under strong acidic or basic conditions and the extent of degradation increased with increasing temperature.
