A novel polyethylene production process by gas polymerization and slurry polymerization based on metallocene-Z/N catalyst system were reported. The polyethylene thus produced had two melting points with broad relative...A novel polyethylene production process by gas polymerization and slurry polymerization based on metallocene-Z/N catalyst system were reported. The polyethylene thus produced had two melting points with broad relative molecular mass distribution ( MWD ). The relative molecular mass, MWD , melt flow rate determined by the ratio of Ti/Zr and of H 2/C 2H 4. The tensile strength of polyethylene produced by metallocenc-Z/N catalyst was higher than that of LL103A.展开更多
Novel WO3/g-C3N4/Ni（OH）x hybrids have been successfully synthesized by a two-step strategy of high temperature calcination and in situ photodeposition.Their photocatalytic performance was investigated using TEOA as ...Novel WO3/g-C3N4/Ni（OH）x hybrids have been successfully synthesized by a two-step strategy of high temperature calcination and in situ photodeposition.Their photocatalytic performance was investigated using TEOA as a hole scavenger under visible light irradiation.The loading of WO3 and Ni（OH）x cocatalysts boosted the photocatalytic H2 evolution efficiency of g-C3N4.WO3/g-C3N4/Ni（OH）x with 20 wt%defective WO3 and 4.8 wt%Ni（OH）x showed the highest hydrogen production rate of 576 μmol/（g·h）,which was 5.7,10.8 and 230 times higher than those of g-C3N4/4.8 wt%Ni（OH）x,20 wt%WO3/C3N4 and g-C3N4 photocatalysts,respectively.The remarkably enhanced H2 evolution performance was ascribed to the combination effects of the Z-scheme heterojunction（WO3/g-C3N4） and loaded cocatalysts（Ni（OH）x）,which effectively inhibited the recombination of the photoexcited electron-hole pairs of g-C3N4 and improved both H2 evolution and TEOA oxidation kinetics.The electron spin resonance spectra of ·O2^- and ·OH radicals provided evidence for the Z-scheme charge separation mechanism.The loading of easily available Ni（OH）x cocatalysts on the Z-scheme WO3/g-C3N4 nanocomposites provided insights into constructing a robust multiple-heterojunction material for photocatalytic applications.展开更多
Heterogeneous semiconductor photocatalysis is a promising green technology solution to energyand environmental problems.Traditional photocatalyst TiO2,with a wide band gap of3.2eV,canonly be excited by UV light and ut...Heterogeneous semiconductor photocatalysis is a promising green technology solution to energyand environmental problems.Traditional photocatalyst TiO2,with a wide band gap of3.2eV,canonly be excited by UV light and utilizes less than4%of solar energy.Silver phosphate(Ag3PO4)isamong the most active visible‐light‐driven photocatalysts reported.Unfortunately,unwanted photocorrosionis the main obstacle to the practical application of Ag3PO4.Much effort has been made inrecent years to address this issue and further enhance the photocatalytic performance of Ag3PO4.The construction of Z‐scheme photocatalytic systems that mimic natural photosynthesis is a promisingstrategy to improve the photocatalytic activity and stability of Ag3PO4.This brief review conciselysummarizes and highlights recent research progress in Ag3PO4‐based all‐solid‐state Z‐schemephotocatalytic systems with or without a solid‐state electron mediator,focusing on their construction,application,and reaction mechanism.Furthermore,the challenges and future prospects ofAg3PO4‐based Z‐scheme photocatalytic systems are discussed.展开更多
文摘A novel polyethylene production process by gas polymerization and slurry polymerization based on metallocene-Z/N catalyst system were reported. The polyethylene thus produced had two melting points with broad relative molecular mass distribution ( MWD ). The relative molecular mass, MWD , melt flow rate determined by the ratio of Ti/Zr and of H 2/C 2H 4. The tensile strength of polyethylene produced by metallocenc-Z/N catalyst was higher than that of LL103A.
基金supported by the National Natural Science Foundation of China (51672089)the Industry and Research Collaborative Innovation Major Projects of Guangzhou (201508020098)+1 种基金the State Key Laboratory of Advanced Technology for Material Synthesis and Processing (Wuhan University of Technology) (2015-KF-7)the Hunan Key Laboratory of Applied Environmental Photocatalysis (Changsha University) (CCSU-XT-04)~~
文摘Novel WO3/g-C3N4/Ni（OH）x hybrids have been successfully synthesized by a two-step strategy of high temperature calcination and in situ photodeposition.Their photocatalytic performance was investigated using TEOA as a hole scavenger under visible light irradiation.The loading of WO3 and Ni（OH）x cocatalysts boosted the photocatalytic H2 evolution efficiency of g-C3N4.WO3/g-C3N4/Ni（OH）x with 20 wt%defective WO3 and 4.8 wt%Ni（OH）x showed the highest hydrogen production rate of 576 μmol/（g·h）,which was 5.7,10.8 and 230 times higher than those of g-C3N4/4.8 wt%Ni（OH）x,20 wt%WO3/C3N4 and g-C3N4 photocatalysts,respectively.The remarkably enhanced H2 evolution performance was ascribed to the combination effects of the Z-scheme heterojunction（WO3/g-C3N4） and loaded cocatalysts（Ni（OH）x）,which effectively inhibited the recombination of the photoexcited electron-hole pairs of g-C3N4 and improved both H2 evolution and TEOA oxidation kinetics.The electron spin resonance spectra of ·O2^- and ·OH radicals provided evidence for the Z-scheme charge separation mechanism.The loading of easily available Ni（OH）x cocatalysts on the Z-scheme WO3/g-C3N4 nanocomposites provided insights into constructing a robust multiple-heterojunction material for photocatalytic applications.
基金supported by the Youth Foundation of Hebei Education Department(QN2017115)the National Natural Science Foundation of China(51504079)~~
文摘Heterogeneous semiconductor photocatalysis is a promising green technology solution to energyand environmental problems.Traditional photocatalyst TiO2,with a wide band gap of3.2eV,canonly be excited by UV light and utilizes less than4%of solar energy.Silver phosphate(Ag3PO4)isamong the most active visible‐light‐driven photocatalysts reported.Unfortunately,unwanted photocorrosionis the main obstacle to the practical application of Ag3PO4.Much effort has been made inrecent years to address this issue and further enhance the photocatalytic performance of Ag3PO4.The construction of Z‐scheme photocatalytic systems that mimic natural photosynthesis is a promisingstrategy to improve the photocatalytic activity and stability of Ag3PO4.This brief review conciselysummarizes and highlights recent research progress in Ag3PO4‐based all‐solid‐state Z‐schemephotocatalytic systems with or without a solid‐state electron mediator,focusing on their construction,application,and reaction mechanism.Furthermore,the challenges and future prospects ofAg3PO4‐based Z‐scheme photocatalytic systems are discussed.
