The microwave absorption properties of Ti_(2)O_(3)were systematically investigated.Experimental results indicate that Ti_(2)O_(3)has microwave absorption performance with a minimum reflection loss value of-37.6 d B at...The microwave absorption properties of Ti_(2)O_(3)were systematically investigated.Experimental results indicate that Ti_(2)O_(3)has microwave absorption performance with a minimum reflection loss value of-37.6 d B at 18.6 GHz and an effective absorption bandwidth(RL<-10 d B)of 2 GHz.Further,vacancy defects were introduced into Ti_(2)O_(3)by carbothermal reduction.Interestingly,the effective absorption bandwidth of Ti_(2)O_(3)with vacancy defects reach 3.2 GHz.First-principles calculations provide evidence that vacancy defects result in the changes of electric dipole state,leading to a wider effective absorption bandwidth.These results have significance in understanding the origin of electromagnetic phenomena and developing electromagnetic wave absorption materials.展开更多
The surface reactivity of metals is fundamentally dependent on the local electronic structure generally tailored by atomic compositions and configurations during the synthesis.Herein,we demonstrate that Cu,which is in...The surface reactivity of metals is fundamentally dependent on the local electronic structure generally tailored by atomic compositions and configurations during the synthesis.Herein,we demonstrate that Cu,which is inert for oxygen reduction reaction(ORR)due to the fully occupied d-orbital,could be activated by applying a visible-light irradiation at ambient temperature.The ORR current is increased to 3.3 times higher in the potential range between-0.1 and 0.4 V under the light of 400 mW·cm^-2,and the activity enhancement is proportional to the light intensity.Together with the help of the first-principle calculation,the remarkably enhanced electrocatalytic activity is expected to stem mainly from the decreased metal-adsorbate binding by photoexcita-tion.This finding provides an additional degree of freedom for controlling and manipulating the surface reactivity of metal catalysts besides materials strategy.展开更多
基金the National Natural Science Foundation of China(Nos.52071071,51431005,51571056,51771048 and 51601033)the Liao Ning Revitalization Talents Program(No.XLYC1802023)the Fundamental Research Funds for the Central Universities of China(Nos.N180204011 and N180204013)。
文摘The microwave absorption properties of Ti_(2)O_(3)were systematically investigated.Experimental results indicate that Ti_(2)O_(3)has microwave absorption performance with a minimum reflection loss value of-37.6 d B at 18.6 GHz and an effective absorption bandwidth(RL<-10 d B)of 2 GHz.Further,vacancy defects were introduced into Ti_(2)O_(3)by carbothermal reduction.Interestingly,the effective absorption bandwidth of Ti_(2)O_(3)with vacancy defects reach 3.2 GHz.First-principles calculations provide evidence that vacancy defects result in the changes of electric dipole state,leading to a wider effective absorption bandwidth.These results have significance in understanding the origin of electromagnetic phenomena and developing electromagnetic wave absorption materials.
基金supported by the National Natural Science Foundation of China(Grant No.51771047)the Fundamental Research Funds for the Central Universities(N180204014)。
文摘The surface reactivity of metals is fundamentally dependent on the local electronic structure generally tailored by atomic compositions and configurations during the synthesis.Herein,we demonstrate that Cu,which is inert for oxygen reduction reaction(ORR)due to the fully occupied d-orbital,could be activated by applying a visible-light irradiation at ambient temperature.The ORR current is increased to 3.3 times higher in the potential range between-0.1 and 0.4 V under the light of 400 mW·cm^-2,and the activity enhancement is proportional to the light intensity.Together with the help of the first-principle calculation,the remarkably enhanced electrocatalytic activity is expected to stem mainly from the decreased metal-adsorbate binding by photoexcita-tion.This finding provides an additional degree of freedom for controlling and manipulating the surface reactivity of metal catalysts besides materials strategy.
