Thermal replacement reaction: a novel route for synthesizing eco-friendly ZnO@γ-In2Se3 hetero-nanostructures by replacing cadmium with indium and their photoelectrochemical and photocatalytic performances

Abstract

A novel route called thermal replacement reaction was demonstrated for synthesizing eco-friendly ZnO@γ-In₂Se₃ hetero-structural nanowires on FTO glass by replacing the element cadmium with indium for the first time. The indium layer was coated on the surface of the ZnO nanowires beforehand, then CdSe quantum dots were deposited onto the coated indium layer, and finally the CdSe quantum dots were converted to γ-In₂Se₃ quantum dots by annealing under vacuum at 350 °C for one hour. The prepared ZnO@γ-In₂Se₃ hetero-nanostructures exhibit stable photoelectrochemical properties that can be ascribed to the protection of the In₂O₃ layer between the ZnO nanowire and γ-In₂Se₃ quantum dots and better photocatalytic performance in the wide wavelength region from 400 nm to nearly 750 nm. This strategy for preparing the ZnO@γ-In₂Se₃ hetero-nanostructures not only enriches our understanding of the single replacement reaction where the active element cadmium can be replaced with indium, but also opens a new way for the in situ conversion of cadmium-based to eco-friendly indium-based nano-devices.