摘要
Large scale zigzag zinc blende single crystal ZnS nanowires have been successfully synthesized during a vapor phase growth process together with a small yield of straight wurtzite single crystal ZnS nanowires.AuPd alloy nanoparticles were utilized to catalyze a vapor-solid-solid growth process of both types of ZnS nanowires,instead of the more common vapor-liquid-solid growth process.Surprisingly,the vapor-phase grown zigzag zinc blende ZnS nanowires are metastable under high-energy electron irradiation in a transmission electron microscope,with straight wurtzite nanowires being much more stable.Upon exposure to electron irradiation,a wurtzite ZnO nanoparticle layer formed on the zigzag zinc blende ZnS nanowire surface with concomitant displacement damage.Both electron inelastic scattering and surface oxidation as a result of electron-beam heating occur during this structure evolution process.When prolonged higher-voltage electron irradiation was applied,local zinc blende ZnS nanowire bodies evolved into ZnS-ZnO nanocables,and dispersed ZnS-ZnO nanoparticle networks.Random AuPd nanoparticles were observed distributed on zigzag ZnS nanowire surfaces,which might be responsible for a catalytic oxidation effect and speed up the surface oxidation-induced structure evolution.
基金
The authors are grateful for the financial support from the University of Connecticut New Faculty start-up funds,and the University of Connecticut Large Faculty Research Grant
Acknowledgement is also made to the Donors of the American Chemical Society Petroleum Research Fund for partial support of this research.
