p-d轨道之间的相互作用是一种提升电催化性能的有效方法.然而,其对主族金属的电催化CO_(2)还原(eCO_(2)RR)的增强机制尚不清晰.因此,我们向金属Bi纳米片中引入了一系列过渡金属氧化物(TMO:Fe_(2)O_(3)、Co_(3)O_(4)、NiO),并以此研究引...p-d轨道之间的相互作用是一种提升电催化性能的有效方法.然而,其对主族金属的电催化CO_(2)还原(eCO_(2)RR)的增强机制尚不清晰.因此,我们向金属Bi纳米片中引入了一系列过渡金属氧化物(TMO:Fe_(2)O_(3)、Co_(3)O_(4)、NiO),并以此研究引入TMO对Bi物种eCO_(2)RR性能的影响.根据原位傅里叶变换红外光谱(FTIR)和CO_(2)-程序升温脱附(TPD)的结果,Bi/TMO中的TMO可以增强CO_(2)的吸附和活化能力.密度泛函理论(DFT)计算结果表明,Bi活性位点^(*)OCHO吸附能及p轨道的优化可以降低CO_(2)到^(*)OCHO过程和^(*)OCHO到HCOOH过程的理论过电位.同时,由于Bi与TMO之间因复合而发生的电子重排也促进了催化剂与反应物之间的电子传输.因此,在热力学和动力学的双重作用下,Bi/TMO中的Bi活性位点表现出最佳的催化能力,在更宽的电位区间内实现了更高的催化活性和甲酸选择性.其中,Bi/Fe_(2)O_(3)的增强效果最为显著.在500 mV的宽电位区间内达到较高的甲酸的法拉第效率(>90%),在-0.8 VRHE时,甲酸的法拉第效率达到最大值99.7%(Bi的1.11倍),甲酸局部电流密度达到12.65 mA cm^(-2)(Bi的1.86倍).这一研究不仅建立了eCO_(2)RR性能增强与引入TMO之间的关系,也为理性设计高性能电催化剂提供了一条实用的、可扩展的途径.展开更多
We study the charge trapping phenomenon that restricts the endurance of n-type ferroelectric field-effect transistors(FeFETs)with metal/ferroelectric/interlayer/Si(MFIS)gate stack structure.In order to explore the phy...We study the charge trapping phenomenon that restricts the endurance of n-type ferroelectric field-effect transistors(FeFETs)with metal/ferroelectric/interlayer/Si(MFIS)gate stack structure.In order to explore the physical mechanism of the endurance failure caused by the charge trapping effect,we first establish a model to simulate the electron trapping behavior in n-type Si FeFET.The model is based on the quantum mechanical electron tunneling theory.And then,we use the pulsed I_d-V_g method to measure the threshold voltage shift between the rising edges and falling edges of the FeFET.Our model fits the experimental data well.By fitting the model with the experimental data,we get the following conclusions.(i)During the positive operation pulse,electrons in the Si substrate are mainly trapped at the interface between the ferroelectric(FE)layer and interlayer(IL)of the FeFET gate stack by inelastic trap-assisted tunneling.(ii)Based on our model,we can get the number of electrons trapped into the gate stack during the positive operation pulse.(iii)The model can be used to evaluate trap parameters,which will help us to further understand the fatigue mechanism of FeFET.展开更多
基金the support of this research by the National Natural Science Foundation of China (U20A20250 and 22179035)the Science Fund for Distinguished Young Scholars of Heilongjiang Province (JQ2022B001)+3 种基金the Fundamental Research Funds for Youth Science and Technology Innovation Team Project of Heilongjiang Province (2021-KYYWF-0030)the China Postdoctoral Science Foundation (2019M651313)the Universities Fundamental Research Funds of Heilongjiang Province (RCCXYJ201806 and 2022-KYYWF-1063)University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province (UNPYSCT-2020006)。
文摘p-d轨道之间的相互作用是一种提升电催化性能的有效方法.然而,其对主族金属的电催化CO_(2)还原(eCO_(2)RR)的增强机制尚不清晰.因此,我们向金属Bi纳米片中引入了一系列过渡金属氧化物(TMO:Fe_(2)O_(3)、Co_(3)O_(4)、NiO),并以此研究引入TMO对Bi物种eCO_(2)RR性能的影响.根据原位傅里叶变换红外光谱(FTIR)和CO_(2)-程序升温脱附(TPD)的结果,Bi/TMO中的TMO可以增强CO_(2)的吸附和活化能力.密度泛函理论(DFT)计算结果表明,Bi活性位点^(*)OCHO吸附能及p轨道的优化可以降低CO_(2)到^(*)OCHO过程和^(*)OCHO到HCOOH过程的理论过电位.同时,由于Bi与TMO之间因复合而发生的电子重排也促进了催化剂与反应物之间的电子传输.因此,在热力学和动力学的双重作用下,Bi/TMO中的Bi活性位点表现出最佳的催化能力,在更宽的电位区间内实现了更高的催化活性和甲酸选择性.其中,Bi/Fe_(2)O_(3)的增强效果最为显著.在500 mV的宽电位区间内达到较高的甲酸的法拉第效率(>90%),在-0.8 VRHE时,甲酸的法拉第效率达到最大值99.7%(Bi的1.11倍),甲酸局部电流密度达到12.65 mA cm^(-2)(Bi的1.86倍).这一研究不仅建立了eCO_(2)RR性能增强与引入TMO之间的关系,也为理性设计高性能电催化剂提供了一条实用的、可扩展的途径.
基金Project supported by the National Natural Science Foundation of China(Grant No.92264104)。
文摘We study the charge trapping phenomenon that restricts the endurance of n-type ferroelectric field-effect transistors(FeFETs)with metal/ferroelectric/interlayer/Si(MFIS)gate stack structure.In order to explore the physical mechanism of the endurance failure caused by the charge trapping effect,we first establish a model to simulate the electron trapping behavior in n-type Si FeFET.The model is based on the quantum mechanical electron tunneling theory.And then,we use the pulsed I_d-V_g method to measure the threshold voltage shift between the rising edges and falling edges of the FeFET.Our model fits the experimental data well.By fitting the model with the experimental data,we get the following conclusions.(i)During the positive operation pulse,electrons in the Si substrate are mainly trapped at the interface between the ferroelectric(FE)layer and interlayer(IL)of the FeFET gate stack by inelastic trap-assisted tunneling.(ii)Based on our model,we can get the number of electrons trapped into the gate stack during the positive operation pulse.(iii)The model can be used to evaluate trap parameters,which will help us to further understand the fatigue mechanism of FeFET.
