PTC热敏陶瓷的无铅化是绿色智能加热及电路智能保护元件研制的重要前提。为了获得可在空气气氛下烧结且兼具高居里温度和高升阻比的无铅化PTC热敏陶瓷,本工作采用固相法制备了(1-x)BaTiO_(3)-0.5 x Bi_(0.5)Na_(0.5)TiO_(3)-0.5 x Bi_(0...PTC热敏陶瓷的无铅化是绿色智能加热及电路智能保护元件研制的重要前提。为了获得可在空气气氛下烧结且兼具高居里温度和高升阻比的无铅化PTC热敏陶瓷,本工作采用固相法制备了(1-x)BaTiO_(3)-0.5 x Bi_(0.5)Na_(0.5)TiO_(3)-0.5 x Bi_(0.5)K_(0.5)TiO_(3)和0.98BaTiO_(3)-0.02 y Bi0.5 Na_(0.5)TiO_(3)-0.02(1-y)Bi_(0.5)K_(0.5)TiO_(3)三元固溶体系无铅PTC热敏陶瓷材料,研究了不同含量的Na和K元素对无铅PTC热敏陶瓷材料的烧结特性和电学性能的影响。结果表明,BNT和BKT均与BaTiO_(3)形成固溶体,随着BNT含量的增加,PTC陶瓷平均晶粒尺寸减小,当BNT和BKT含量相同时,PTC陶瓷可以在较宽的烧结温度范围内实现半导化,且在空气气氛下烧结温度为1200℃的陶瓷样品具有最佳的PTC效应,其室温电阻率为128Ω·cm,升阻比为5个数量级,居里温度为142℃。展开更多
以高纯a-Al_2O_3粉与AlN粉为原料,采用无压烧结,通过气氛渗透,在烧制过程中掺入等量碳的方法制备AlON:C透明陶瓷,研究AlON:C透明陶瓷的光释光性能。结果发现:AlON:C透明陶瓷光释光衰变曲线都随着时间呈指数变化衰减,前期衰减快,后期衰...以高纯a-Al_2O_3粉与AlN粉为原料,采用无压烧结,通过气氛渗透,在烧制过程中掺入等量碳的方法制备AlON:C透明陶瓷,研究AlON:C透明陶瓷的光释光性能。结果发现:AlON:C透明陶瓷光释光衰变曲线都随着时间呈指数变化衰减,前期衰减快,后期衰减速率变慢;470 nm蓝光不能清空光释光信号,光释光有信号堆积现象。β射线辐照下,AlON:C陶瓷的光释光剂量响应曲线呈线性、亚线性,并有趋向饱和的特点;AlON:C透明陶瓷对b射线的光释光响应曲线在50 m Gy^50 Gy与50~100 Gy吸收剂量范围内呈非常良好的线性关系;在50~500 m Gy吸收剂量范围内,β与γ射线光释光响应线性良好,γ射线辐照下的光释光强度约为β射线辐照下的光释光强度的76%。展开更多
The production of renewable fuels through water splitting via photocatalytic hydrogen production holds significant promise.Nonetheless,the sluggish kinetics of hydrogen evolution and the inadequate water adsorption on...The production of renewable fuels through water splitting via photocatalytic hydrogen production holds significant promise.Nonetheless,the sluggish kinetics of hydrogen evolution and the inadequate water adsorption on photocatalysts present notable challenges.In this study,we have devised a straightforward hydrothermal method to synthesize Bi_(2)O_(3)(BO)derived from metal‐organic frameworks(MOFs),loaded with flower-like ZnIn_(2)S_(4)(ZIS).This approach substantially enhances water adsorption and surface catalytic reactions,resulting in a remarkable enhancement of photocatalytic activity.By employing triethanolamine(TEOA)as a sacrificial agent,the hydrogen evolution rate achieved with 15%(mass fraction)ZIS loading on BO reached an impressive value of 1610μmol∙h^(−1)∙g^(−1),marking a 6.34-fold increase compared to that observed for bare BO.Furthermore,through density functional theory(DFT)and ab initio molecular dynamics(AIMD)calculations,we have identified the reactions occurring at the ZIS/BO S-scheme heterojunction interface,including the identification of active sites for water adsorption and catalytic reactions.This study provides valuable insights into the development of high-performance composite photocatalytic materials with tailored electronic properties and wettability.展开更多
文摘PTC热敏陶瓷的无铅化是绿色智能加热及电路智能保护元件研制的重要前提。为了获得可在空气气氛下烧结且兼具高居里温度和高升阻比的无铅化PTC热敏陶瓷,本工作采用固相法制备了(1-x)BaTiO_(3)-0.5 x Bi_(0.5)Na_(0.5)TiO_(3)-0.5 x Bi_(0.5)K_(0.5)TiO_(3)和0.98BaTiO_(3)-0.02 y Bi0.5 Na_(0.5)TiO_(3)-0.02(1-y)Bi_(0.5)K_(0.5)TiO_(3)三元固溶体系无铅PTC热敏陶瓷材料,研究了不同含量的Na和K元素对无铅PTC热敏陶瓷材料的烧结特性和电学性能的影响。结果表明,BNT和BKT均与BaTiO_(3)形成固溶体,随着BNT含量的增加,PTC陶瓷平均晶粒尺寸减小,当BNT和BKT含量相同时,PTC陶瓷可以在较宽的烧结温度范围内实现半导化,且在空气气氛下烧结温度为1200℃的陶瓷样品具有最佳的PTC效应,其室温电阻率为128Ω·cm,升阻比为5个数量级,居里温度为142℃。
文摘以高纯a-Al_2O_3粉与AlN粉为原料,采用无压烧结,通过气氛渗透,在烧制过程中掺入等量碳的方法制备AlON:C透明陶瓷,研究AlON:C透明陶瓷的光释光性能。结果发现:AlON:C透明陶瓷光释光衰变曲线都随着时间呈指数变化衰减,前期衰减快,后期衰减速率变慢;470 nm蓝光不能清空光释光信号,光释光有信号堆积现象。β射线辐照下,AlON:C陶瓷的光释光剂量响应曲线呈线性、亚线性,并有趋向饱和的特点;AlON:C透明陶瓷对b射线的光释光响应曲线在50 m Gy^50 Gy与50~100 Gy吸收剂量范围内呈非常良好的线性关系;在50~500 m Gy吸收剂量范围内,β与γ射线光释光响应线性良好,γ射线辐照下的光释光强度约为β射线辐照下的光释光强度的76%。
文摘The production of renewable fuels through water splitting via photocatalytic hydrogen production holds significant promise.Nonetheless,the sluggish kinetics of hydrogen evolution and the inadequate water adsorption on photocatalysts present notable challenges.In this study,we have devised a straightforward hydrothermal method to synthesize Bi_(2)O_(3)(BO)derived from metal‐organic frameworks(MOFs),loaded with flower-like ZnIn_(2)S_(4)(ZIS).This approach substantially enhances water adsorption and surface catalytic reactions,resulting in a remarkable enhancement of photocatalytic activity.By employing triethanolamine(TEOA)as a sacrificial agent,the hydrogen evolution rate achieved with 15%(mass fraction)ZIS loading on BO reached an impressive value of 1610μmol∙h^(−1)∙g^(−1),marking a 6.34-fold increase compared to that observed for bare BO.Furthermore,through density functional theory(DFT)and ab initio molecular dynamics(AIMD)calculations,we have identified the reactions occurring at the ZIS/BO S-scheme heterojunction interface,including the identification of active sites for water adsorption and catalytic reactions.This study provides valuable insights into the development of high-performance composite photocatalytic materials with tailored electronic properties and wettability.
