Preparation And Photocatalytic Properties Of Pn-type Cu₂O/CdS Nanowires

In this paper,pn-type Cu₂O/CdS nanowires were fabricated in alumina?AAO?template by potentiostatic method.The surface morphology and structure of nanowires were characterized.Finally current-voltage characteristic of pn junction,photoelectric performances and photocatalytic properties were researched.The pn-type Cu₂O/CdS nanowires were fabricated by two steps.Firstly Cu2 O nanowires were fabricated on AAO template electrode by potentiostatic method.Then Cd S nanowires were deposited on Cu2O/AAO electrode with the same method.The deposition of Cu2 O nanowires were carried out in-0.28 V at 55?.The deposition of Cd S nanowires were carried out in-1.0 V at 50 ?.Mott-Schokkty results showed that Cu2 O was a p-type semiconductor and Cd S was an n-type semiconductor.So Cu₂O/CdS nanowires were pn-type structure.The multilayered pn-type Cu₂O/CdS nanowires were fabricated by depositing Cu2 O nanowires and Cd S nanowires on Cu₂O/CdS/AAO electrode alternately.The diameters of pn-type nanowires were 100 nm,which were the same as AAO template.The lengths of pn-type Cu₂O/CdS nanowires and multilayered pn-type Cu₂O/CdS nanowires were about 2 ?m and 4 ?m,respectively.XRD results indicated that Cu₂O/CdS nanowires were consisted of a mixed crystal structures of cubic and hexagonal of the Cd S and cubic structure of the Cu2 O.The result of current-voltage characteristic indicated that pn-type Cu₂O/CdS nanowires had rectification characteristic.The results of photoelectric response showed that multilayered pn-type Cu₂O/CdS nanowires had a better photoelectric performance than pn-type Cu₂O/CdS nanowires.Comparing with Cd S nanowires and Cu2 O nanowires,the apsorption edge of pn-type Cu₂O/CdS nanowires and multilayered pn-type Cu₂O/CdS nanowires showed a red-shift.Especially for multilayered pn-type Cu₂O/CdS nanowires,the red-shift was more obvious and it had a large absorbance.Photocatalytic degradation of Rhodamine B results showed that the degradation efficiency of multilayered pn-type Cu₂O/CdS nanowires,pn-type Cu₂O/CdS nanowires and Cu2 O nanowires were 84.22%,66.02% and 48.20% after 7 hours.The reaction kinetics obeyed first-order kinetics.