Exploring the structure-activity relationship between the performance of gas sensors and the structure of semiconductor metal oxide(SMO)nanomaterials is crucial for understanding and designing gas-sensing materials an...Exploring the structure-activity relationship between the performance of gas sensors and the structure of semiconductor metal oxide(SMO)nanomaterials is crucial for understanding and designing gas-sensing materials and overcoming the application limitations of SMO-based gas sensors.Regulation of a single SMO microstructure provides a promising solution to address this scientific problem due to its controllable composition.In this study,we control the grain boundary(GB)density of Fe_(2)O_(3)nanomaterials using a simple solvothermal method.They have similar chemical compositions and crystal phases,providing an ideal platform for studying the influence of the GB density on the gas-sensing performance.Gas-sensing tests showed that the Fe_(2)O_(3)-1 sensor with medium GB density and the Fe_(2)O_(3)-2 sensor with high GB density had higher sensitivity and selectivity than the Fe_(2)O_(3)-0 sensors with low GB density before reaching the optimal operating temperature.However,when the GB density increased,the response to acetone decreased slightly,whereas the optimal operating temperature decreased.This work highlights the unique performance of the GB density in enhancing the gas sensitivity of a single SMO.展开更多
metal oxide electronic interactions in composite electrocatalysts have a considerable impact on their catalytic capability.In this study,we successfully synthesized an electrocatalytic material composed of MoO_(3)/C s...metal oxide electronic interactions in composite electrocatalysts have a considerable impact on their catalytic capability.In this study,we successfully synthesized an electrocatalytic material composed of MoO_(3)/C speciessupported Pd nanoparticles(Pd-MoO_(3)/C)using a convenient hydrothermal method,which exhibited excellent catalytic activities for both ethanol oxidation and oxygen reduction in KOH media.The specific activity of PdMoO_(3)/C toward ethanol oxidation with MoO_(3)loading(40wt%)was~2.6 times greater than that for the commercial Pd/C(10 wt%)with the same Pd content.In particular,the activity could effectively hold up to~60%of its maximum activity after 500-cycle tests,demonstrating improved cyclical stability.Notably,the fast electron transfer kinetics toward oxygen reduction for Pd-MoO_(3)/C(40%)were also comparable to those of commercial Pt/C(20 wt%)catalysts.These superior electrochemical features are primarily derived from the stronger electronic coupling between Pd and MoO_(3)through charge transfer,which can supply more active centers and improve the anti-poisoning ability.Meanwhile,the MoO_(3)species in the Pd-MoO_(3)/C composite may provide additional benefits in terms of electrical conductivity and dispersion.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.21571119 and 22209102)the Program for New Century Excellent Talents in University of Ministry of Education of China(No.NCET-12-1035)+2 种基金the Natural Science Foundation of Shanxi Province(Nos.202203021211253 and 20210302124473)the Postgraduate Innovation Project of Shanxi Normal University(No.2022XSY022)China Postdoctoral Science Foundation(No.2021M691366)。
文摘Exploring the structure-activity relationship between the performance of gas sensors and the structure of semiconductor metal oxide(SMO)nanomaterials is crucial for understanding and designing gas-sensing materials and overcoming the application limitations of SMO-based gas sensors.Regulation of a single SMO microstructure provides a promising solution to address this scientific problem due to its controllable composition.In this study,we control the grain boundary(GB)density of Fe_(2)O_(3)nanomaterials using a simple solvothermal method.They have similar chemical compositions and crystal phases,providing an ideal platform for studying the influence of the GB density on the gas-sensing performance.Gas-sensing tests showed that the Fe_(2)O_(3)-1 sensor with medium GB density and the Fe_(2)O_(3)-2 sensor with high GB density had higher sensitivity and selectivity than the Fe_(2)O_(3)-0 sensors with low GB density before reaching the optimal operating temperature.However,when the GB density increased,the response to acetone decreased slightly,whereas the optimal operating temperature decreased.This work highlights the unique performance of the GB density in enhancing the gas sensitivity of a single SMO.
基金financially supported by the Natural Science Foundation of Shanxi Province(No.201901D111277)the National Natural Science Foundation of China(No.21571119)+1 种基金the Graduate Science and Technology Innovation Project Foundation of Shanxi Normal University(No.2021DCXM71)the Program for New Century Excellent Talents in University(No.NCET-12-1035)。
文摘metal oxide electronic interactions in composite electrocatalysts have a considerable impact on their catalytic capability.In this study,we successfully synthesized an electrocatalytic material composed of MoO_(3)/C speciessupported Pd nanoparticles(Pd-MoO_(3)/C)using a convenient hydrothermal method,which exhibited excellent catalytic activities for both ethanol oxidation and oxygen reduction in KOH media.The specific activity of PdMoO_(3)/C toward ethanol oxidation with MoO_(3)loading(40wt%)was~2.6 times greater than that for the commercial Pd/C(10 wt%)with the same Pd content.In particular,the activity could effectively hold up to~60%of its maximum activity after 500-cycle tests,demonstrating improved cyclical stability.Notably,the fast electron transfer kinetics toward oxygen reduction for Pd-MoO_(3)/C(40%)were also comparable to those of commercial Pt/C(20 wt%)catalysts.These superior electrochemical features are primarily derived from the stronger electronic coupling between Pd and MoO_(3)through charge transfer,which can supply more active centers and improve the anti-poisoning ability.Meanwhile,the MoO_(3)species in the Pd-MoO_(3)/C composite may provide additional benefits in terms of electrical conductivity and dispersion.
