Cu-based electrocatalysts have become the focus in the field of electrochemical CO_(2) reduction reaction(ECO_(2) RR)due to their ability to produce multicarbon products.However,the research on generating single carbo...Cu-based electrocatalysts have become the focus in the field of electrochemical CO_(2) reduction reaction(ECO_(2) RR)due to their ability to produce multicarbon products.However,the research on generating single carbon products with higher economic feasibility via ECO_(2) RR based on Cu-based electrocatalysts is rather rare,and the roles of the surface architecture and oxides of the electrocatalysts have not been explained exactly.In this work,a two-step method including thermal oxidation and electroreduction is proposed to introduce Cuþinto pure Cu foil to form Cu_(2)O/Cu electrocatalyst.By regulating the surface composition and morphology of the electrocatalyst in this way,the activity of ECO 2 RR to C_(1) products has been greatly improved.The Faradaic efficiency of carbon products of the Cu_(2)O/Cu electrode reaches 84%at?0.7 V vs.RHE with good selectivity for HCOOH and CO.The current density of Cu_(2)O/Cu electrode reaches-12.21 mA cm^(2) at-0.8 V vs.RHE,which is much higher than that of the Cu foil electrode(?0.09 mA cm?2).In-situ Raman characterization shows that Cuþin Cu_(2)O/Cu electrode could inhibit hydrogen generation and promote ECO_(2) RR by stabilizing the adsorption of CO_(2).展开更多
An unstable solid electrolyte interphase(SEI)and chaotic lithium ion fux are key impediments to commercial high-energy-density lithium batteries because of the uncontrolled growth of rigid lithium dendrites,which woul...An unstable solid electrolyte interphase(SEI)and chaotic lithium ion fux are key impediments to commercial high-energy-density lithium batteries because of the uncontrolled growth of rigid lithium dendrites,which would pierce through the conventional polypropylene(PP)separator,causing short circuit and safety issues.Herein,the homogenization of lithium ion fux and the generation of stable SEI layers on lithium anodes were achieved via coating a fuorine-functionalized Ti_(3)C_(2)(F-Ti_(3)C_(2))nanosheets on PP separator(F-Ti_(3)C_(2)@PP).F-Ti_(3)C_(2)nanosheets provide abundant ions pathways to homogeneously manipulate lithium ion fux and increase the Young’s modulus and electrolyte wettability of the separators.In addition,F species derived from the F-Ti_(3)C_(2)nanosheets would promote the formation of Li F-rich SEI film.The synergistic effect contribute to the uniform lithium deposition.Symmetric Li|Li,asymmetric Li|Cu and full Li|Li Fe PO4cells incorporated with the modified separators exhibit improved electrochemical performance even under lean electrolyte conditions.This work provides a feasible strategy to improve the performance of lithium batteries through both fuoridized SEI formation and lithium ion fux manipulation.展开更多
Flexible-robust hydrogen-bonded organic frameworks(HOFs)are attracting increasing interest due to their excellent separation performance for important industrial gases,but the construction remains challenging.Herein,a...Flexible-robust hydrogen-bonded organic frameworks(HOFs)are attracting increasing interest due to their excellent separation performance for important industrial gases,but the construction remains challenging.Herein,a sticked-layer strategy is first proposed to construct a flexible-robust HOF,HOFFJU-8,from a donor(D)–π–acceptor(A)molecule 4,4′,4″,4‴-(pyrrolo[3,2-b]pyrrole-1,2,4,5-tetrayl)tetrabenzonitrile(DP-4CN).HOF-FJU-8 is amicroporous three-dimensional framework composed of two kinds of DP-4CN molecules,one acting as building units for the two-dimensional layer via C≡N···H–C hydrogen bond dimers and another as the sticks to link the layers along channels through D–Aπ···πinteractions.The activated framework HOF-FJU-8a possesses flexible-robust pore characteristics,as determined by the gas adsorption and in situ gas-loaded powder X-ray diffraction.HOF-FJU-8a exhibits adaptive adsorption and stronger binding affinity to C_(2)H_(2)rather than CO_(2)due to the flexible-robust nature,which can effectively separate acetylene and carbon dioxide mixtures.展开更多
基金supported by National Natural Science Foundation of China(No.52071183).
文摘Cu-based electrocatalysts have become the focus in the field of electrochemical CO_(2) reduction reaction(ECO_(2) RR)due to their ability to produce multicarbon products.However,the research on generating single carbon products with higher economic feasibility via ECO_(2) RR based on Cu-based electrocatalysts is rather rare,and the roles of the surface architecture and oxides of the electrocatalysts have not been explained exactly.In this work,a two-step method including thermal oxidation and electroreduction is proposed to introduce Cuþinto pure Cu foil to form Cu_(2)O/Cu electrocatalyst.By regulating the surface composition and morphology of the electrocatalyst in this way,the activity of ECO 2 RR to C_(1) products has been greatly improved.The Faradaic efficiency of carbon products of the Cu_(2)O/Cu electrode reaches 84%at?0.7 V vs.RHE with good selectivity for HCOOH and CO.The current density of Cu_(2)O/Cu electrode reaches-12.21 mA cm^(2) at-0.8 V vs.RHE,which is much higher than that of the Cu foil electrode(?0.09 mA cm?2).In-situ Raman characterization shows that Cuþin Cu_(2)O/Cu electrode could inhibit hydrogen generation and promote ECO_(2) RR by stabilizing the adsorption of CO_(2).
基金financially supported by the National Natural Science Foundation of China(21931005,21871177,20172012002)the Natural Science Foundation of Shanghai(20ZR1427600)the Shanghai Science and Technology Committee(19JC1412600)。
文摘An unstable solid electrolyte interphase(SEI)and chaotic lithium ion fux are key impediments to commercial high-energy-density lithium batteries because of the uncontrolled growth of rigid lithium dendrites,which would pierce through the conventional polypropylene(PP)separator,causing short circuit and safety issues.Herein,the homogenization of lithium ion fux and the generation of stable SEI layers on lithium anodes were achieved via coating a fuorine-functionalized Ti_(3)C_(2)(F-Ti_(3)C_(2))nanosheets on PP separator(F-Ti_(3)C_(2)@PP).F-Ti_(3)C_(2)nanosheets provide abundant ions pathways to homogeneously manipulate lithium ion fux and increase the Young’s modulus and electrolyte wettability of the separators.In addition,F species derived from the F-Ti_(3)C_(2)nanosheets would promote the formation of Li F-rich SEI film.The synergistic effect contribute to the uniform lithium deposition.Symmetric Li|Li,asymmetric Li|Cu and full Li|Li Fe PO4cells incorporated with the modified separators exhibit improved electrochemical performance even under lean electrolyte conditions.This work provides a feasible strategy to improve the performance of lithium batteries through both fuoridized SEI formation and lithium ion fux manipulation.
基金supported by the National Natural Science Foundation of China(grant nos.22271046,21971038,and 21975044)the Fujian Provincial Department of Science and Technology(grant no.2019L3004).
文摘Flexible-robust hydrogen-bonded organic frameworks(HOFs)are attracting increasing interest due to their excellent separation performance for important industrial gases,but the construction remains challenging.Herein,a sticked-layer strategy is first proposed to construct a flexible-robust HOF,HOFFJU-8,from a donor(D)–π–acceptor(A)molecule 4,4′,4″,4‴-(pyrrolo[3,2-b]pyrrole-1,2,4,5-tetrayl)tetrabenzonitrile(DP-4CN).HOF-FJU-8 is amicroporous three-dimensional framework composed of two kinds of DP-4CN molecules,one acting as building units for the two-dimensional layer via C≡N···H–C hydrogen bond dimers and another as the sticks to link the layers along channels through D–Aπ···πinteractions.The activated framework HOF-FJU-8a possesses flexible-robust pore characteristics,as determined by the gas adsorption and in situ gas-loaded powder X-ray diffraction.HOF-FJU-8a exhibits adaptive adsorption and stronger binding affinity to C_(2)H_(2)rather than CO_(2)due to the flexible-robust nature,which can effectively separate acetylene and carbon dioxide mixtures.
