BiOX(X=Cl,I,Br)has attracted intensive interest as a photocatalyst for environmental remediation,but its limited pho-tocatalytic activity versus visible light irradiation restricts its practical application.Herein,a F...BiOX(X=Cl,I,Br)has attracted intensive interest as a photocatalyst for environmental remediation,but its limited pho-tocatalytic activity versus visible light irradiation restricts its practical application.Herein,a Fe^(3+)-doped BiOCl_(x)I_(1-x)solid solution(Fe-BiOCl_(x)I_(1-x))was synthesized in situ on an amidoxime-functionalized fibrous support via a one-pot solvothermal approach.Comprehensive characterization and DFT calculations indicate that the robust chelated interaction between ami-doxime groups and Fe^(3+)greatly boosts the crystal growth of nanosized Fe-BiOCl_(x)I_(1–x)on the fibrous surface,simultaneously tunes its electronic structure for improved light harvesting and oxygen vacancy creation,and enables the fibrous support to act as an electron sink for efficient charge separation.These synergistic qualities result in high photocatalytic activity for the degradation of organic contaminants,which outperforms that obtained for unsupported Fe-BiOCl_(x)I_(1-x)and other fibrous samples by several times.Our findings highlight the importance of functionalized support design for the development of efficient BiOX photocatalysts under visible light irradiation.展开更多
The precipitation behavior of different phases in a high-silicon stainless steel(6 wt%Si)during aging at 600–1050℃for24 h was investigated.The morphology,crystal structure and composition of various precipitates wer...The precipitation behavior of different phases in a high-silicon stainless steel(6 wt%Si)during aging at 600–1050℃for24 h was investigated.The morphology,crystal structure and composition of various precipitates were detailly characterized using optical microscopy,scanning electron microscopy and transmission electron microscopy.Four phases were mainly identified:χ-phase,M_6C carbides,σphase and a new type of fcc-phase.During aging at 600–900℃,the main precipitate was(Cr,Mo and Si)-richχ-phase which was directly precipitated fromγmatrix.Theχ-phase was calibrated as bcc structure with a lattice parameter of 8.90?.The peak temperature for the precipitation ofχ-phase was 800℃,and it was dissolved when aging at temperatures above 1000℃.Theσ-phase was observed only at 700℃and grew next toχ-phase.Above 700℃,a new fcc-phase was found to be precipitated along withχ-phase,with a space group of Fd3c and a lattice parameter of 12.56?.The M_6C carbides started to be precipitated at 700℃in the vicinity ofχ-phase.And its amount basically increased with the increasing of temperature.An orientation relationship between M_6C/γwas found:[100]c//[100]γ,(001)c//(001)γ,i.e.,the cube-on-cube relationship.展开更多
基金supported by the National Natural Science Foundation of China(No.5200319221806121)+1 种基金Special Fund Project for Technology Innovation of Tianjin City(20YDTPJC00920)Natural Science Foundation of Tianjin City(15JCQNJC06300).
文摘BiOX(X=Cl,I,Br)has attracted intensive interest as a photocatalyst for environmental remediation,but its limited pho-tocatalytic activity versus visible light irradiation restricts its practical application.Herein,a Fe^(3+)-doped BiOCl_(x)I_(1-x)solid solution(Fe-BiOCl_(x)I_(1-x))was synthesized in situ on an amidoxime-functionalized fibrous support via a one-pot solvothermal approach.Comprehensive characterization and DFT calculations indicate that the robust chelated interaction between ami-doxime groups and Fe^(3+)greatly boosts the crystal growth of nanosized Fe-BiOCl_(x)I_(1–x)on the fibrous surface,simultaneously tunes its electronic structure for improved light harvesting and oxygen vacancy creation,and enables the fibrous support to act as an electron sink for efficient charge separation.These synergistic qualities result in high photocatalytic activity for the degradation of organic contaminants,which outperforms that obtained for unsupported Fe-BiOCl_(x)I_(1-x)and other fibrous samples by several times.Our findings highlight the importance of functionalized support design for the development of efficient BiOX photocatalysts under visible light irradiation.
文摘The precipitation behavior of different phases in a high-silicon stainless steel(6 wt%Si)during aging at 600–1050℃for24 h was investigated.The morphology,crystal structure and composition of various precipitates were detailly characterized using optical microscopy,scanning electron microscopy and transmission electron microscopy.Four phases were mainly identified:χ-phase,M_6C carbides,σphase and a new type of fcc-phase.During aging at 600–900℃,the main precipitate was(Cr,Mo and Si)-richχ-phase which was directly precipitated fromγmatrix.Theχ-phase was calibrated as bcc structure with a lattice parameter of 8.90?.The peak temperature for the precipitation ofχ-phase was 800℃,and it was dissolved when aging at temperatures above 1000℃.Theσ-phase was observed only at 700℃and grew next toχ-phase.Above 700℃,a new fcc-phase was found to be precipitated along withχ-phase,with a space group of Fd3c and a lattice parameter of 12.56?.The M_6C carbides started to be precipitated at 700℃in the vicinity ofχ-phase.And its amount basically increased with the increasing of temperature.An orientation relationship between M_6C/γwas found:[100]c//[100]γ,(001)c//(001)γ,i.e.,the cube-on-cube relationship.
