A novel hydrangea-like boron and nitrogen co-doped carbon material synthesised by the cross-linking reaction of spiny spherical polymers and co-doped with boron and nitrogen(B/N)via high-temperature calcination was us...A novel hydrangea-like boron and nitrogen co-doped carbon material synthesised by the cross-linking reaction of spiny spherical polymers and co-doped with boron and nitrogen(B/N)via high-temperature calcination was used to construct an electrochemical sensor for the detection of aristolochic acid.Under optimal conditions,the sensor showed good electrochemical response to aristolochic acid,with a theoretical detection limit of 47.3 nmol/L and the sensitivity reaching 0.31μA Lμmol^(-1)cm^(-2).Moreover,the sensor was successfully applied to the detection of aristolochic acid in the extracts of Chinese herbal medicine samples,and the detection results were consistent with those of high-performance liquid chromatography.With a strong selectivity for substances to be measured in complex environments,this study provides a new and efficient method by which to detect aristolochic acid in Chinese herbal medicine,which greatly expands the application field of B/N heteroatom-doped carbon materials.展开更多
Carbon materials have shown remarkable usefulness in facilitating the performance of insulating sulfur cathode for lithium–sulfur batteries owing to their excellent conductivity and porous structure. However,the anxi...Carbon materials have shown remarkable usefulness in facilitating the performance of insulating sulfur cathode for lithium–sulfur batteries owing to their excellent conductivity and porous structure. However,the anxiety is the poor affinity toward polar polysulfides due to the intrinsic nonpolar surface of carbon.Herein, we report a direct pyrolysis of the mixture urea and boric acid to synthesize B/N–codoped hierarchically porous carbon nanosheets(B–N–CSs) as efficient sulfur host for lithium–sulfur battery. The graphene–like B–N–CSs provides high specific surface area and porous structure with abundant micropores(1.1 nm) and low–range mesopores(2.3 nm), thereby constraining the sulfur active materials within the pores. More importantly, the codoped B/N elements can further enhance the polysulfide confinement through strong Li–N and B–S interaction based on the Lewis acid–base theory. These structural superiorities significantly suppress the shuttle effect by both physical confinement and chemical interaction, and promote the redox kinetics of polysulfide conversion. When evaluated as the cathode host, the S/B–N–CSs composite displays the excellent performance with a high reversible capacity up to 772 m A h g–1 at 0.5 C and a low fading rate of ^0.09% per cycle averaged upon 500 cycles. In particular, remarkable stability with a high capacity retention of 87.1% can be realized when augmenting the sulfur loading in the cathode up to 4.6 mg cm^(-2).展开更多
基金funded by the National Natural Science Foundation of China(No.22476170)Science and Technology Talent and Platform Program of Yunnan Provincial Science and Technology Department(No.202505AW340011)。
文摘A novel hydrangea-like boron and nitrogen co-doped carbon material synthesised by the cross-linking reaction of spiny spherical polymers and co-doped with boron and nitrogen(B/N)via high-temperature calcination was used to construct an electrochemical sensor for the detection of aristolochic acid.Under optimal conditions,the sensor showed good electrochemical response to aristolochic acid,with a theoretical detection limit of 47.3 nmol/L and the sensitivity reaching 0.31μA Lμmol^(-1)cm^(-2).Moreover,the sensor was successfully applied to the detection of aristolochic acid in the extracts of Chinese herbal medicine samples,and the detection results were consistent with those of high-performance liquid chromatography.With a strong selectivity for substances to be measured in complex environments,this study provides a new and efficient method by which to detect aristolochic acid in Chinese herbal medicine,which greatly expands the application field of B/N heteroatom-doped carbon materials.
基金financial support of the National Natural Science Foundation of China (Grant No. 21263016, 21363015, 51662029, 21863006)the Youth Science Foundation of Jiangxi Province (Grant No. 20192BAB216001)the Key Laboratory of Jiangxi Province for Environment and Energy Catalysis (20181BCD40004)。
文摘Carbon materials have shown remarkable usefulness in facilitating the performance of insulating sulfur cathode for lithium–sulfur batteries owing to their excellent conductivity and porous structure. However,the anxiety is the poor affinity toward polar polysulfides due to the intrinsic nonpolar surface of carbon.Herein, we report a direct pyrolysis of the mixture urea and boric acid to synthesize B/N–codoped hierarchically porous carbon nanosheets(B–N–CSs) as efficient sulfur host for lithium–sulfur battery. The graphene–like B–N–CSs provides high specific surface area and porous structure with abundant micropores(1.1 nm) and low–range mesopores(2.3 nm), thereby constraining the sulfur active materials within the pores. More importantly, the codoped B/N elements can further enhance the polysulfide confinement through strong Li–N and B–S interaction based on the Lewis acid–base theory. These structural superiorities significantly suppress the shuttle effect by both physical confinement and chemical interaction, and promote the redox kinetics of polysulfide conversion. When evaluated as the cathode host, the S/B–N–CSs composite displays the excellent performance with a high reversible capacity up to 772 m A h g–1 at 0.5 C and a low fading rate of ^0.09% per cycle averaged upon 500 cycles. In particular, remarkable stability with a high capacity retention of 87.1% can be realized when augmenting the sulfur loading in the cathode up to 4.6 mg cm^(-2).
