The rational design of photochemical molecular device(PMD)and its hybrid system has great potential in improving the activity of photocatalytic hydrogen production.A series of Pd6L3 type metal-organic cages,denoted as...The rational design of photochemical molecular device(PMD)and its hybrid system has great potential in improving the activity of photocatalytic hydrogen production.A series of Pd6L3 type metal-organic cages,denoted as MOC-Py-M(M=H,Cu,and Zn),are designed for PMDs by combining metalloporphyrin-based ligands with catalytically active Pd^(2+)centers.These metal-organic cages(MOCs)are first successfully hybridized with graphitic carbon nitride(g-C_(3)N_(4))to form direct Z-scheme heterogeneous MOC-Py-M/g-C_(3)N_(4)(M=H,Cu,and Zn)photocatalysts via π-πinteractions.Benefiting from its better light absorption ability,the MOC-Py-Zn/g-C_(3)N_(4) catalyst exhibits high H_(2) production activity under visible light(10348μmol g^(-1) h^(-1)),far superior to MOC-Py-H/g-C_(3)N_(4) and MOC-Py-Cu/g-C_(3)N_(4).Moreover,the MOC-Py-Zn/g-C_(3)N_(4) system obtains an enhanced turn over number(TON)value of 32616 within 100 h,outperforming the homogenous MOC-Py-Zn(TON of 507 within 100 h),which is one of the highest photochemical hybrid systems based on MOC for visible-light-driven hydrogen generation.This confirms the direct Z-scheme heterostructure can promote effective charge transfer,expand the visible light absorption region,and protect the cages from decomposition in MOC-Py-Zn/g-C_(3)N_(4).This work presents a creative example that direct Z-scheme PMD-based systems for effective and persistent hydrogen generation from water under visible light are obtained by heterogenization approach using homogeneous porphyrin-based MOCs and g-C_(3)N_(4) semiconductors.展开更多
分别用 Li 和 Cl 作为 p 型和 n 型掺杂剂,成功地制作了 ZnSep—n 结发光二极管。ZnSe 作为直接带隙Ⅱ—Ⅵ族半导体,近年来已经引起人们明显的关注。～2.7eV的室温宽带隙使其成为制作蓝色发光器件,例如 LED 和激光器的很具吸引力的材料...分别用 Li 和 Cl 作为 p 型和 n 型掺杂剂,成功地制作了 ZnSep—n 结发光二极管。ZnSe 作为直接带隙Ⅱ—Ⅵ族半导体,近年来已经引起人们明显的关注。～2.7eV的室温宽带隙使其成为制作蓝色发光器件,例如 LED 和激光器的很具吸引力的材料。制作 ZnSe LED 和激光器,需要通过控制替位掺杂形成 p—n 结(或异质结)。虽然 p 型掺杂是目前制作这样器件的主要障碍,但在高浓度条件下,n 型掺杂剂的有效激活具有同等的重要性,尤其是如果要研制蓝色的ZnSe 激光器,更是如此。展开更多
文摘The rational design of photochemical molecular device(PMD)and its hybrid system has great potential in improving the activity of photocatalytic hydrogen production.A series of Pd6L3 type metal-organic cages,denoted as MOC-Py-M(M=H,Cu,and Zn),are designed for PMDs by combining metalloporphyrin-based ligands with catalytically active Pd^(2+)centers.These metal-organic cages(MOCs)are first successfully hybridized with graphitic carbon nitride(g-C_(3)N_(4))to form direct Z-scheme heterogeneous MOC-Py-M/g-C_(3)N_(4)(M=H,Cu,and Zn)photocatalysts via π-πinteractions.Benefiting from its better light absorption ability,the MOC-Py-Zn/g-C_(3)N_(4) catalyst exhibits high H_(2) production activity under visible light(10348μmol g^(-1) h^(-1)),far superior to MOC-Py-H/g-C_(3)N_(4) and MOC-Py-Cu/g-C_(3)N_(4).Moreover,the MOC-Py-Zn/g-C_(3)N_(4) system obtains an enhanced turn over number(TON)value of 32616 within 100 h,outperforming the homogenous MOC-Py-Zn(TON of 507 within 100 h),which is one of the highest photochemical hybrid systems based on MOC for visible-light-driven hydrogen generation.This confirms the direct Z-scheme heterostructure can promote effective charge transfer,expand the visible light absorption region,and protect the cages from decomposition in MOC-Py-Zn/g-C_(3)N_(4).This work presents a creative example that direct Z-scheme PMD-based systems for effective and persistent hydrogen generation from water under visible light are obtained by heterogenization approach using homogeneous porphyrin-based MOCs and g-C_(3)N_(4) semiconductors.
基金the financial supports by the Anhui Provincial Natural Science Foundation (Grant No.1508085MB28)the National Natural Science Foundation of China (Grant No.51372062)~~
文摘分别用 Li 和 Cl 作为 p 型和 n 型掺杂剂,成功地制作了 ZnSep—n 结发光二极管。ZnSe 作为直接带隙Ⅱ—Ⅵ族半导体,近年来已经引起人们明显的关注。～2.7eV的室温宽带隙使其成为制作蓝色发光器件,例如 LED 和激光器的很具吸引力的材料。制作 ZnSe LED 和激光器,需要通过控制替位掺杂形成 p—n 结(或异质结)。虽然 p 型掺杂是目前制作这样器件的主要障碍,但在高浓度条件下,n 型掺杂剂的有效激活具有同等的重要性,尤其是如果要研制蓝色的ZnSe 激光器,更是如此。
