Hierarchical porous TiO_2 nanopills were synthesized using a titanium metal-organic framework MIL-125(Ti) as precursor. The as-synthesized TiO_2 nanopills owned a large specific surface area of 102 m^2/g and unique po...Hierarchical porous TiO_2 nanopills were synthesized using a titanium metal-organic framework MIL-125(Ti) as precursor. The as-synthesized TiO_2 nanopills owned a large specific surface area of 102 m^2/g and unique porous structure. Furthermore, the obtained TiO_2 nanopills were applied as anode materials for Na-ion batteries for the first time. The as-synthesized TiO_2 nanopills achieved a high discharge capacity of 196.4 m Ah/g at a current density of 0.1 A/g. A discharge capacity of 115.9 m Ah/g was obtained at a high current density of 0.5 A/g and the capacity retention was remained as high as 90% even after 3000 cycles. The excellent electrochemical performance can be attributed to its unique hierarchical porous feature.展开更多
Sluggish oxygen evolution reaction(OER)and oxygen reduction reaction(ORR)kinetics inevitably impede the practical performance of rechargeable zinc-air batteries.Thus,combing the structural designability of transition ...Sluggish oxygen evolution reaction(OER)and oxygen reduction reaction(ORR)kinetics inevitably impede the practical performance of rechargeable zinc-air batteries.Thus,combing the structural designability of transition metal-based electrocatalysts with anionic regulation is highly desired.Herein,mesoporous lamellar-stacked cobalt-based nanopiles with surface-sulfurization modification are elaborately designed and integrated with N/S co-doped graphene to build a robust OER/ORR bifunctional electrocatalyst.The lamellar-stacking mode of mesoporous nanosheets with abundant channels accelerates gas-liquid mass transfer,and partial-sulfurization of cobalt-based matrix surface efficiently improves the intrinsic OER activity.Meanwhile,N/S co-doped graphene further reinforces the ORR active sites while providing a stable conductive skeleton.As expected,this composite electrocatalyst delivers considerable bifunctional activity and stability,with an OER overpotential of 323 m V at 10 m A cm^(-2)and high durability.When applied in zinc-air batteries,remarkable ultralong-term stability over 4000 cycles and a maximum power density of 150.1 m W cm^(-2)are achieved.This work provides new insight into structurecomposition synergistic design of rapid-kinetics OER/ORR bifunctional electrocatalyst for nextgeneration metal-air batteries.展开更多
基金supported by JSPS KAKENHI Grant Number15K00597Takahashi Industrial and Economic Research Foundation Japan Grant Number 06-003-154
文摘Hierarchical porous TiO_2 nanopills were synthesized using a titanium metal-organic framework MIL-125(Ti) as precursor. The as-synthesized TiO_2 nanopills owned a large specific surface area of 102 m^2/g and unique porous structure. Furthermore, the obtained TiO_2 nanopills were applied as anode materials for Na-ion batteries for the first time. The as-synthesized TiO_2 nanopills achieved a high discharge capacity of 196.4 m Ah/g at a current density of 0.1 A/g. A discharge capacity of 115.9 m Ah/g was obtained at a high current density of 0.5 A/g and the capacity retention was remained as high as 90% even after 3000 cycles. The excellent electrochemical performance can be attributed to its unique hierarchical porous feature.
基金supported by the National Natural Science Foundation of China (21905157,22279077,21905056)the Hainan Provincial Natural Science Foundation of China (221RC452)+1 种基金the Start-up Research Foundation of Hainan University (KYQD (ZR)21059,KYQD (ZR)-21063)the Natural Science Foundation of Shanghai (22ZR1424500)。
文摘Sluggish oxygen evolution reaction(OER)and oxygen reduction reaction(ORR)kinetics inevitably impede the practical performance of rechargeable zinc-air batteries.Thus,combing the structural designability of transition metal-based electrocatalysts with anionic regulation is highly desired.Herein,mesoporous lamellar-stacked cobalt-based nanopiles with surface-sulfurization modification are elaborately designed and integrated with N/S co-doped graphene to build a robust OER/ORR bifunctional electrocatalyst.The lamellar-stacking mode of mesoporous nanosheets with abundant channels accelerates gas-liquid mass transfer,and partial-sulfurization of cobalt-based matrix surface efficiently improves the intrinsic OER activity.Meanwhile,N/S co-doped graphene further reinforces the ORR active sites while providing a stable conductive skeleton.As expected,this composite electrocatalyst delivers considerable bifunctional activity and stability,with an OER overpotential of 323 m V at 10 m A cm^(-2)and high durability.When applied in zinc-air batteries,remarkable ultralong-term stability over 4000 cycles and a maximum power density of 150.1 m W cm^(-2)are achieved.This work provides new insight into structurecomposition synergistic design of rapid-kinetics OER/ORR bifunctional electrocatalyst for nextgeneration metal-air batteries.
