The low specific capacitances(SCs)of traditional carbonaceous negative electrodes significantly limit the enhancement in energy density of aqueous hybrid supercapacitors(AHCs).It is still hugely challengeable to explo...The low specific capacitances(SCs)of traditional carbonaceous negative electrodes significantly limit the enhancement in energy density of aqueous hybrid supercapacitors(AHCs).It is still hugely challengeable to explore a candidate with large SCs,which can stably operate in the negative potential region mean-while.For this propose,we design and fabricate solid-solution Ru_(x)Cu_(1-x)O_(2) nanocrystals(NCs),which exhibit competitive SCs and electrochemical stability within the potential range from-0.9 V to 0.0 V in the aqueous KOH electrolyte.The incorporation of Cu enhances the electrochemical utilization of RuO_(2),reaction kinetics,electronic conductivity,and hydrogen evolution overpotentials,which are all highly dependent upon the added contents of Cu species.The optimized Ru_(0.8)Cu_(0.2)O_(2)(RuCu82)electrode of a high mass loading of 5 mg cm^(-2) reveals the best electrochemical capacitances in terms of reversible SCs and capacitance degradation at room temperature and-20℃.Furthermore,the reversible K^(+)-(de)intercalation induced pseudocapacitance is proposed for electrochemical charge storage process of RuCu82.In particu-lar,remarkable specific energy of 59.1 Wh kg-1 at 400 W kg-1 and excellent cycling stability are achieved in the assembled NiCoO_(2)//RuCu82 AHCs.Our contribution here presents a new promising negative elec-trode platform with high SCs and electrochemical stability for next-generation AHCs.展开更多
We report for the first time a Na-ion battery anode material composed of P-doped CoSe_(2)nanoparticles(P-CoSe_(2))with the size of 5–20 nm that are uniformly embed in a 3 D porous honeycomb-like carbon network.High r...We report for the first time a Na-ion battery anode material composed of P-doped CoSe_(2)nanoparticles(P-CoSe_(2))with the size of 5–20 nm that are uniformly embed in a 3 D porous honeycomb-like carbon network.High rate capability and cycling stability are achieved simultaneously.The honeycomb-like carbon network is rationally designed to support high electrical conductivity,rapid Na-ion diffusion as well as the accommodation of the volume expansion from the active P-CoSe_(2)nanoparticles.In particular,heteroatom P-doping within CoSe_(2)introduces stronger P-Co bonds and additional P-Se bonds that significantly improve the structure stability of P-CoSe_(2)for highly stable sodiation/desodiation over long-term cycling.P-doping also improves the electrical conductivity of the CoSe_(2)nanoparticles,leading to highly elevated electrochemical kinetics to deliver high specific capacities at high current densities.Benefiting from the unique nanostructure and atomic-level P-doping,the P-CoSe_(2)(2:1)/C anode delivers an excellent cycle stability with a specific capacity of 206.9 mA h g^(-1)achieved at 2000 mA g^(-1)after 1000 cycles.In addition,this material can be synthesized using a facile pyrolysis and selenization/phosphorization approach.This study provides new opportunities of heteroatom doping as an effective method to improve the cycling stability of Na-ion anode materials.展开更多
Advancement of Co-N-C materials for efficient oxygen reduction reaction(ORR)is essential,given their potential as highly attractive alternatives to Pt-based catalysts.Here,we propose a novel strategy for the controlla...Advancement of Co-N-C materials for efficient oxygen reduction reaction(ORR)is essential,given their potential as highly attractive alternatives to Pt-based catalysts.Here,we propose a novel strategy for the controllable evolution of active Co sites via constructing a carbon substrate to fabricate a highperformance Co-N-C catalyst for ORR,which involves initiating a metallic Co phase adjacent to atomic Co sites to modify the electronic structures and promote synergistic effects.The resulting catalyst(CSDB-Co)demonstrates exceptional ORR activity(E_(1/2)=0.95 V vs.RHE)and zinc-air battery capability surpassing the benchmark catalysts in alkaline solutions.As evidenced by density functional theory(DFT)calculations,the remarkable ORR performance of C-SDB-Co originates from the synergy between the two Co phases that effectively regulates the electronic structure and lowers the energy barrier of intermediate adsorption.This study provides a new perspective on enhancing the catalytic activity of Co-N-C materials through innovative carbon substrate design and active site regulation.展开更多
Intraventricular haemorrhage(IVH)is defined as the eruption of blood in the cerebroventricular system and occurs mostly secondary to intracerebral haemorrhage(ICH)in adults.Hydrocephalus is a severe complication of IV...Intraventricular haemorrhage(IVH)is defined as the eruption of blood in the cerebroventricular system and occurs mostly secondary to intracerebral haemorrhage(ICH)in adults.Hydrocephalus is a severe complication of IVH that can serve as an independent predictor of increased mortality.In this mini-review,we focus on the mechanisms of hydrocephalus after adult IVH,including blood-clot blockage,barrier impairment,inflammation and blood components,and attempt to reconcile the current research findings into a unified framework.We expect our theoretical framework to help guide future clinical and basic research leading to improved monitoring and intervention for IVH and subsequent hydrocephalus.展开更多
Single-atomic Fe-N4 is the well-acknowledged active site in iron-nitrogen-carbon(Fe-N-C)material for oxygen reduction reaction(ORR).The adjusting of the electronic distribution of Fe-N4 is promising for further enhanc...Single-atomic Fe-N4 is the well-acknowledged active site in iron-nitrogen-carbon(Fe-N-C)material for oxygen reduction reaction(ORR).The adjusting of the electronic distribution of Fe-N4 is promising for further enhancing the performance of the Fe-N-C catalyst.Herein,a phosphorus(P)-doped Fe-N-C catalyst with penta-coordinated single atom sites(FeNPC)is reported for efficient oxygen reduction.Fe K-edge X-ray absorption spectroscopy(XAS)verifies the coordination environment of single Fe atom,while density functional theory(DFT)calculations reveal that the penta-coordination and neighboring doped P atoms can simultaneously change the electronic distribution of Fe-N_(4)and its adsorption strength of key intermediates,reducing the reactionfree energy of the potential-limiting step.Electrochemical tests validate the remarkable intrinsic ORR activity of FeNPC in alkaline media(a half-wave potential(E_(1/2))of 0.904 V vs.reversible hydrogen electrode(RHE)and limited current density(JL)of 6.23 mA·cm^(−2))and an enhanced ORR performance in neutral(E_(1/2)=0.751 V,J_(L)=5.27 mA·cm^(−2))and acidic media(E_(1/2)=0.735 V,JL=5.82 mA·cm^(−2))with excellent stability,highlighting the benefits of optimizing the local environment of singleatomic Fe-N4.展开更多
基金supported by the National Natural Science Foundation of China(Nos.U22A20145,51904115,52072151,52171211,and 52271218)Jinan Independent Innovative Team(No.2020GXRC015)the Major Program of Shandong Province Natural Science Foundation(Nos.ZR2023ZD43 and ZR2021ZD05).
文摘The low specific capacitances(SCs)of traditional carbonaceous negative electrodes significantly limit the enhancement in energy density of aqueous hybrid supercapacitors(AHCs).It is still hugely challengeable to explore a candidate with large SCs,which can stably operate in the negative potential region mean-while.For this propose,we design and fabricate solid-solution Ru_(x)Cu_(1-x)O_(2) nanocrystals(NCs),which exhibit competitive SCs and electrochemical stability within the potential range from-0.9 V to 0.0 V in the aqueous KOH electrolyte.The incorporation of Cu enhances the electrochemical utilization of RuO_(2),reaction kinetics,electronic conductivity,and hydrogen evolution overpotentials,which are all highly dependent upon the added contents of Cu species.The optimized Ru_(0.8)Cu_(0.2)O_(2)(RuCu82)electrode of a high mass loading of 5 mg cm^(-2) reveals the best electrochemical capacitances in terms of reversible SCs and capacitance degradation at room temperature and-20℃.Furthermore,the reversible K^(+)-(de)intercalation induced pseudocapacitance is proposed for electrochemical charge storage process of RuCu82.In particu-lar,remarkable specific energy of 59.1 Wh kg-1 at 400 W kg-1 and excellent cycling stability are achieved in the assembled NiCoO_(2)//RuCu82 AHCs.Our contribution here presents a new promising negative elec-trode platform with high SCs and electrochemical stability for next-generation AHCs.
基金the Natural Science Foundation of Shandong Province(No.ZR2019QEM001)the Guangdong Basic and Applied Basic Research Foundation(No.2019A1515111089)the National Natural Science Foundation of China(Grant No.22005178)。
文摘We report for the first time a Na-ion battery anode material composed of P-doped CoSe_(2)nanoparticles(P-CoSe_(2))with the size of 5–20 nm that are uniformly embed in a 3 D porous honeycomb-like carbon network.High rate capability and cycling stability are achieved simultaneously.The honeycomb-like carbon network is rationally designed to support high electrical conductivity,rapid Na-ion diffusion as well as the accommodation of the volume expansion from the active P-CoSe_(2)nanoparticles.In particular,heteroatom P-doping within CoSe_(2)introduces stronger P-Co bonds and additional P-Se bonds that significantly improve the structure stability of P-CoSe_(2)for highly stable sodiation/desodiation over long-term cycling.P-doping also improves the electrical conductivity of the CoSe_(2)nanoparticles,leading to highly elevated electrochemical kinetics to deliver high specific capacities at high current densities.Benefiting from the unique nanostructure and atomic-level P-doping,the P-CoSe_(2)(2:1)/C anode delivers an excellent cycle stability with a specific capacity of 206.9 mA h g^(-1)achieved at 2000 mA g^(-1)after 1000 cycles.In addition,this material can be synthesized using a facile pyrolysis and selenization/phosphorization approach.This study provides new opportunities of heteroatom doping as an effective method to improve the cycling stability of Na-ion anode materials.
基金finacially supported by National Natural Sci-ence Foundation of China(Nos.22275210,22171288)Natural Sci-ence Foundation of Shandong Province(No.ZR2022MB009)+1 种基金Out-standing Youth Science Fund Projects of Shandong Province(No.ZR2022YQ15)Fundamental Research Funds for the Central Universities(No.YCX2021142).
文摘Advancement of Co-N-C materials for efficient oxygen reduction reaction(ORR)is essential,given their potential as highly attractive alternatives to Pt-based catalysts.Here,we propose a novel strategy for the controllable evolution of active Co sites via constructing a carbon substrate to fabricate a highperformance Co-N-C catalyst for ORR,which involves initiating a metallic Co phase adjacent to atomic Co sites to modify the electronic structures and promote synergistic effects.The resulting catalyst(CSDB-Co)demonstrates exceptional ORR activity(E_(1/2)=0.95 V vs.RHE)and zinc-air battery capability surpassing the benchmark catalysts in alkaline solutions.As evidenced by density functional theory(DFT)calculations,the remarkable ORR performance of C-SDB-Co originates from the synergy between the two Co phases that effectively regulates the electronic structure and lowers the energy barrier of intermediate adsorption.This study provides a new perspective on enhancing the catalytic activity of Co-N-C materials through innovative carbon substrate design and active site regulation.
基金This study was supported and funded by a grant from the National Science Foundation of China(NSFC)(number 81471168).
文摘Intraventricular haemorrhage(IVH)is defined as the eruption of blood in the cerebroventricular system and occurs mostly secondary to intracerebral haemorrhage(ICH)in adults.Hydrocephalus is a severe complication of IVH that can serve as an independent predictor of increased mortality.In this mini-review,we focus on the mechanisms of hydrocephalus after adult IVH,including blood-clot blockage,barrier impairment,inflammation and blood components,and attempt to reconcile the current research findings into a unified framework.We expect our theoretical framework to help guide future clinical and basic research leading to improved monitoring and intervention for IVH and subsequent hydrocephalus.
基金supported by the National Natural Science Foundation of China(Nos.21875285,22171288,and 22005340)the Key Research and Development Projects of Shandong Province(No.2019JZZY010331)the Natural Science Foundation of Shandong Province(No.ZR2020MB017).
文摘Single-atomic Fe-N4 is the well-acknowledged active site in iron-nitrogen-carbon(Fe-N-C)material for oxygen reduction reaction(ORR).The adjusting of the electronic distribution of Fe-N4 is promising for further enhancing the performance of the Fe-N-C catalyst.Herein,a phosphorus(P)-doped Fe-N-C catalyst with penta-coordinated single atom sites(FeNPC)is reported for efficient oxygen reduction.Fe K-edge X-ray absorption spectroscopy(XAS)verifies the coordination environment of single Fe atom,while density functional theory(DFT)calculations reveal that the penta-coordination and neighboring doped P atoms can simultaneously change the electronic distribution of Fe-N_(4)and its adsorption strength of key intermediates,reducing the reactionfree energy of the potential-limiting step.Electrochemical tests validate the remarkable intrinsic ORR activity of FeNPC in alkaline media(a half-wave potential(E_(1/2))of 0.904 V vs.reversible hydrogen electrode(RHE)and limited current density(JL)of 6.23 mA·cm^(−2))and an enhanced ORR performance in neutral(E_(1/2)=0.751 V,J_(L)=5.27 mA·cm^(−2))and acidic media(E_(1/2)=0.735 V,JL=5.82 mA·cm^(−2))with excellent stability,highlighting the benefits of optimizing the local environment of singleatomic Fe-N4.
