Structural reconstruction of electrocatalysts plays a pivotal role in catalytic performances for CO_(2)reduction reaction(CO_(2)RR),whereas the behavior is by far superficially understood.Here,we report that CO_(2)acc...Structural reconstruction of electrocatalysts plays a pivotal role in catalytic performances for CO_(2)reduction reaction(CO_(2)RR),whereas the behavior is by far superficially understood.Here,we report that CO_(2)accessibility results in a universal self-adaptive structural reconstruction from Cu_(2)O to Cu@CuxO composites,ending with feeding gas-dependent microstructures and catalytic performances.The CO_(2)-rich atmosphere favors reconstruction for CO_(2)RR,whereas the CO_(2)-deficient one prefers that for hydrogen evolution reaction.With the assistance of spectroscopic analysis and theoretical calculations,we uncover a CO_(2)-induced passivation behavior by identifying a reductionresistant but catalytic active Cu(I)-rich amorphous layer stabilized by*CO intermediates.Additionally,we find extra CO production is indispensable for the robust production of C2H4.An inverse correlation between durability and FECO/FEC2H4 is disclosed,suggesting that the selfstabilization process involving the absorption of*CO intermediates on Cu(I)sites is essential for durable electrolysis.Guided by this insight,we design hollow Cu_(2)O nanospheres for durable and selective CO_(2)RR electrolysis in producing C2H4.Our work recognizes the previously overlooked passivation reconstruction and self-stabilizing behavior and highlights the critical role of the local atmosphere in modulating reconstruction and catalytic processes.展开更多
目的建立能同时测定冠心安口服液中蒙花苷、延胡索乙素和2,3,5,4’-四羟基二苯乙烯-2-O-β-D-葡萄糖苷含量的HPLC分析方法。方法Capcell Pak UG C_(18)色谱柱分离;蒙花苷、延胡索乙素和2,3,5,4’-四羟基二苯乙烯-2-O-β-D-葡萄糖苷检测...目的建立能同时测定冠心安口服液中蒙花苷、延胡索乙素和2,3,5,4’-四羟基二苯乙烯-2-O-β-D-葡萄糖苷含量的HPLC分析方法。方法Capcell Pak UG C_(18)色谱柱分离;蒙花苷、延胡索乙素和2,3,5,4’-四羟基二苯乙烯-2-O-β-D-葡萄糖苷检测波长分别设定为334、281、320 nm;柱温为室温;进样体积为10μL;以乙腈为流动相A,1 mL·L^(−1)磷酸溶液(三乙胺调节pH至6.0)为流动相B,梯度洗脱。结果蒙花苷、延胡索乙素和2,3,5,4’-四羟基二苯乙烯-2-O-β-D-葡萄糖苷的质量浓度分别在0.0245~2.4500、0.0457~4.5700、0.0474~4.7400μg·mL^(−1)范围内线性良好;平均回收率分别为100.8%、99.9%、101.4%;精密度和重复性RSD值(n=6)均在5.0%以内;供试品溶液在24 h内稳定。结论此方法具有前处理简单、分析时间短和检测结果准确等优点,适用于冠心安口服液制剂的质量控制。展开更多
P2/O3-type Ni/Mn-based layered oxides are promising cathode materials for sodium-ion batteries(SIBs)owing to their high energy density.However,exploring effective ways to enhance the synergy between the P2 and 03 phas...P2/O3-type Ni/Mn-based layered oxides are promising cathode materials for sodium-ion batteries(SIBs)owing to their high energy density.However,exploring effective ways to enhance the synergy between the P2 and 03 phases remains a necessity.Herein,we design a P2/O3-type Na_(0.76)Ni_(0.31)Zn_(0.07)Mn_(0.50)Ti_(0.12)0_(2)(NNZMT)with high chemical/electrochemical stability by enhancing the coupling between the two phases.For the first time,a unique Na*extraction is observed from a Na-rich O3 phase by a Na-poor P2 phase and systematically investigated.This process is facilitated by Zn^(2+)/Ti^(4+)dual doping and calcination condition regulation,allowing a higher Na*content in the P2 phase with larger Na^(+)transport channels and enhancing Na transport kinetics.Because of reduced Na^(+)in the O3 phase,which increases the difficulty of H^(+)/Na^(+) exchange,the hydrostability of the O3 phase in NNZMT is considerably improved.Furthermore,Zn^(2+)/Ti^(4+)presence in NNZMT synergistically regulates oxygen redox chemistry,which effectively suppresses O_(2)/CO_(2) gas release and electrolyte decomposition,and completely inhibits phase transitions above 4.0 V.As a result,NNZMT achieves a high discharge capacity of 144.8 mA h g^(-1) with a median voltage of 3.42 V at 20 mA g^(-1) and exhibits excellent cycling performance with a capacity retention of 77.3% for 1000 cycles at 2000 mA g^(-1).This study provides an effective strategy and new insights into the design of high-performance layered-oxide cathode materials with enhanced structure/interface stability forSIBs.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.22479097)the Shanghai Science and Technology Committee(Grant No.23ZR1433000)the National High-Level Talent Program for Young Scholars,the Start-up Fund(F.S.)from Shanghai Jiao Tong University.
文摘Structural reconstruction of electrocatalysts plays a pivotal role in catalytic performances for CO_(2)reduction reaction(CO_(2)RR),whereas the behavior is by far superficially understood.Here,we report that CO_(2)accessibility results in a universal self-adaptive structural reconstruction from Cu_(2)O to Cu@CuxO composites,ending with feeding gas-dependent microstructures and catalytic performances.The CO_(2)-rich atmosphere favors reconstruction for CO_(2)RR,whereas the CO_(2)-deficient one prefers that for hydrogen evolution reaction.With the assistance of spectroscopic analysis and theoretical calculations,we uncover a CO_(2)-induced passivation behavior by identifying a reductionresistant but catalytic active Cu(I)-rich amorphous layer stabilized by*CO intermediates.Additionally,we find extra CO production is indispensable for the robust production of C2H4.An inverse correlation between durability and FECO/FEC2H4 is disclosed,suggesting that the selfstabilization process involving the absorption of*CO intermediates on Cu(I)sites is essential for durable electrolysis.Guided by this insight,we design hollow Cu_(2)O nanospheres for durable and selective CO_(2)RR electrolysis in producing C2H4.Our work recognizes the previously overlooked passivation reconstruction and self-stabilizing behavior and highlights the critical role of the local atmosphere in modulating reconstruction and catalytic processes.
基金This work is supported by the National Natural Science Foundation of China(No.22103075,No.21827804,and No.22173089)the National Key R&D Program of China(No.2021YFA0716801andNo.2017YFA0303502).
文摘目的建立能同时测定冠心安口服液中蒙花苷、延胡索乙素和2,3,5,4’-四羟基二苯乙烯-2-O-β-D-葡萄糖苷含量的HPLC分析方法。方法Capcell Pak UG C_(18)色谱柱分离;蒙花苷、延胡索乙素和2,3,5,4’-四羟基二苯乙烯-2-O-β-D-葡萄糖苷检测波长分别设定为334、281、320 nm;柱温为室温;进样体积为10μL;以乙腈为流动相A,1 mL·L^(−1)磷酸溶液(三乙胺调节pH至6.0)为流动相B,梯度洗脱。结果蒙花苷、延胡索乙素和2,3,5,4’-四羟基二苯乙烯-2-O-β-D-葡萄糖苷的质量浓度分别在0.0245~2.4500、0.0457~4.5700、0.0474~4.7400μg·mL^(−1)范围内线性良好;平均回收率分别为100.8%、99.9%、101.4%;精密度和重复性RSD值(n=6)均在5.0%以内;供试品溶液在24 h内稳定。结论此方法具有前处理简单、分析时间短和检测结果准确等优点,适用于冠心安口服液制剂的质量控制。
基金supported by the National Natural Science Foundation of China (22169002)the Chongzuo Key Research and Development Program of China (20220603)the Counterpart Aid Project for Discipline Construction from Guangxi University(2023M02)
文摘P2/O3-type Ni/Mn-based layered oxides are promising cathode materials for sodium-ion batteries(SIBs)owing to their high energy density.However,exploring effective ways to enhance the synergy between the P2 and 03 phases remains a necessity.Herein,we design a P2/O3-type Na_(0.76)Ni_(0.31)Zn_(0.07)Mn_(0.50)Ti_(0.12)0_(2)(NNZMT)with high chemical/electrochemical stability by enhancing the coupling between the two phases.For the first time,a unique Na*extraction is observed from a Na-rich O3 phase by a Na-poor P2 phase and systematically investigated.This process is facilitated by Zn^(2+)/Ti^(4+)dual doping and calcination condition regulation,allowing a higher Na*content in the P2 phase with larger Na^(+)transport channels and enhancing Na transport kinetics.Because of reduced Na^(+)in the O3 phase,which increases the difficulty of H^(+)/Na^(+) exchange,the hydrostability of the O3 phase in NNZMT is considerably improved.Furthermore,Zn^(2+)/Ti^(4+)presence in NNZMT synergistically regulates oxygen redox chemistry,which effectively suppresses O_(2)/CO_(2) gas release and electrolyte decomposition,and completely inhibits phase transitions above 4.0 V.As a result,NNZMT achieves a high discharge capacity of 144.8 mA h g^(-1) with a median voltage of 3.42 V at 20 mA g^(-1) and exhibits excellent cycling performance with a capacity retention of 77.3% for 1000 cycles at 2000 mA g^(-1).This study provides an effective strategy and new insights into the design of high-performance layered-oxide cathode materials with enhanced structure/interface stability forSIBs.
