Photocatalytic degradation of volatile organic compounds(VOCs)is a significant applying aspect of pho-tocatalysis.Both the modulation of photocatalysts and the rational dispersion of them on supports are key for solar...Photocatalytic degradation of volatile organic compounds(VOCs)is a significant applying aspect of pho-tocatalysis.Both the modulation of photocatalysts and the rational dispersion of them on supports are key for solar-driven VOC degradation.Conventional batch-type photoreactors have low efficiency while continuous-flow photoreactors suffer from the problem of incomplete removal of VOCs.Herein,aiming for continuous and complete degradation of toluene gas as the target contaminant,continuous-flow pho-tocatalytic degradation reactors were made by adhering the vanadium and nitrogen codoped TiO_(2)on honeycomb ceramics(V/N-TiO_(2)@HC)by a simple sol-gel method.In such a reactor,the rich ordered pores in the HC accelerate mass transport of toluene,and the introduction of V/N dopants narrows the bandgap and widens the light absorption range of TiO_(2),together resulting in continuous and nearly-complete pho-tocatalytic degradation of toluene.The unique and stable structure of HC allows the photocatalysts to be reused.The degradation rate of toluene gas can reach 97.8%,and after 24 rounds of photocatalytic degra-dation,there is still a degradation rate of 96.7%.The impacts of loading times and gaseous flow rate on the photocatalytic performance of V/N-TiO_(2)@HC are studied in detail.Our study provides a practical so-lution for the continuous and complete photocatalytic degradation of VOCs and opens a new application field for HC.展开更多
V-N微合金化处理是提高非调质船用钢板力学性能的重要途径。本文通过OM(optical microscope)、SEM(scanning electron microscope)、TEM(transmission electron microscope)、EBSD(electron backscatter diffrac‑tion)等微观分析手段,...V-N微合金化处理是提高非调质船用钢板力学性能的重要途径。本文通过OM(optical microscope)、SEM(scanning electron microscope)、TEM(transmission electron microscope)、EBSD(electron backscatter diffrac‑tion)等微观分析手段,系统表征了不同微合金化试验钢的显微组织,并利用万能拉伸试验机和金属夏比V形缺口摆锤冲击试验仪测试了其力学性能。结果表明,V-N微合金化有效细化了晶粒尺寸,使其平均晶粒直径都为10μm以下,其中V-N试验钢的晶粒为9.1μm,V-N-Ti试验钢的晶粒细化最为显著,为8μm。更重要的是促进了晶内针状铁素体的形成,增加了大角度晶界的比例,V-N试验钢的大角度晶界所占比例最高为77%、V-N-Ti试验钢的大角度晶界所占比例为63.4%。此外,还生成了弥散分布的V(C,N)和(Ti,V)(C,N)。V-N微合金化后试验钢强度与塑性明显提升,V-N-Ti试验钢的强度相较于V-N试验钢进一步提升但塑性却有所降低。在-60℃低温冲击下,V-N微合金化后试验钢的冲击吸收功、裂纹扩展功均明显升高,断裂模式从0V-0Ti试验钢的以准解理断裂为主的脆性断裂转变为V-N试验钢的具有大量等轴韧窝的微孔聚集型韧性断裂,V-N-Ti试验钢由于大角度晶界比例降低及析出物粗化,与V-N试验钢相比,V-N-Ti钢的低温韧性有所下降。V-N微合金化通过“晶粒细化+针状铁素体调控+纳米析出”的多重协同机制,实现了船板钢强韧性的综合提升,而钛的复合添加在带来更强沉淀强化效果的同时,也对韧性构成制约。V-N船板钢实现了强度、塑性与低温韧性的最佳匹配。展开更多
基金financial support of this work from the Key Research and Development Project of Gansu Province(No.20YF3GA008)the Lanzhou Science and Technology Lanzhou Science and Technology Bureau Project(No.2022-2-15)+1 种基金Gansu Provincial Science and Technology Commissioner Special Project(No.22CX8GA106)Key Research and Development Project of Gansu Natural Energy Institute(No.2019YF-02).
文摘Photocatalytic degradation of volatile organic compounds(VOCs)is a significant applying aspect of pho-tocatalysis.Both the modulation of photocatalysts and the rational dispersion of them on supports are key for solar-driven VOC degradation.Conventional batch-type photoreactors have low efficiency while continuous-flow photoreactors suffer from the problem of incomplete removal of VOCs.Herein,aiming for continuous and complete degradation of toluene gas as the target contaminant,continuous-flow pho-tocatalytic degradation reactors were made by adhering the vanadium and nitrogen codoped TiO_(2)on honeycomb ceramics(V/N-TiO_(2)@HC)by a simple sol-gel method.In such a reactor,the rich ordered pores in the HC accelerate mass transport of toluene,and the introduction of V/N dopants narrows the bandgap and widens the light absorption range of TiO_(2),together resulting in continuous and nearly-complete pho-tocatalytic degradation of toluene.The unique and stable structure of HC allows the photocatalysts to be reused.The degradation rate of toluene gas can reach 97.8%,and after 24 rounds of photocatalytic degra-dation,there is still a degradation rate of 96.7%.The impacts of loading times and gaseous flow rate on the photocatalytic performance of V/N-TiO_(2)@HC are studied in detail.Our study provides a practical so-lution for the continuous and complete photocatalytic degradation of VOCs and opens a new application field for HC.
文摘V-N微合金化处理是提高非调质船用钢板力学性能的重要途径。本文通过OM(optical microscope)、SEM(scanning electron microscope)、TEM(transmission electron microscope)、EBSD(electron backscatter diffrac‑tion)等微观分析手段,系统表征了不同微合金化试验钢的显微组织,并利用万能拉伸试验机和金属夏比V形缺口摆锤冲击试验仪测试了其力学性能。结果表明,V-N微合金化有效细化了晶粒尺寸,使其平均晶粒直径都为10μm以下,其中V-N试验钢的晶粒为9.1μm,V-N-Ti试验钢的晶粒细化最为显著,为8μm。更重要的是促进了晶内针状铁素体的形成,增加了大角度晶界的比例,V-N试验钢的大角度晶界所占比例最高为77%、V-N-Ti试验钢的大角度晶界所占比例为63.4%。此外,还生成了弥散分布的V(C,N)和(Ti,V)(C,N)。V-N微合金化后试验钢强度与塑性明显提升,V-N-Ti试验钢的强度相较于V-N试验钢进一步提升但塑性却有所降低。在-60℃低温冲击下,V-N微合金化后试验钢的冲击吸收功、裂纹扩展功均明显升高,断裂模式从0V-0Ti试验钢的以准解理断裂为主的脆性断裂转变为V-N试验钢的具有大量等轴韧窝的微孔聚集型韧性断裂,V-N-Ti试验钢由于大角度晶界比例降低及析出物粗化,与V-N试验钢相比,V-N-Ti钢的低温韧性有所下降。V-N微合金化通过“晶粒细化+针状铁素体调控+纳米析出”的多重协同机制,实现了船板钢强韧性的综合提升,而钛的复合添加在带来更强沉淀强化效果的同时,也对韧性构成制约。V-N船板钢实现了强度、塑性与低温韧性的最佳匹配。
