Recent development of core–shell SnO₂ nanostructures and their potential applications

Abstract

This feature article highlights the recent development of core–shell SnO₂ nanostructures for their potential applications, i.e. optical, electrical, photo-electrochemical, photo-catalytic and gas sensing. Current studies reveal that the core–shell SnO₂ nanocrystals could pave the way for developing new challenging devices because core–shell structures exhibit significant improvement of different physical properties, e.g. electrical, optical, electrochemical, etc. Here, we mainly highlight the impacts of core–shell structures of SnO₂ nanocrystals on optical, electrical, photo-electrochemical, photo-catalytic and gas sensing properties. To begin with, we illustrate general synthesis methodologies for preparing core–shell SnO₂ nanostructures and describe the structural changes due to the formation of core–shell nanocrystals. Successively, we emphasize the fundamental understanding of free charge carrier generation, charge transfer, charge separation, and interfacial charge transfer of the core–shell structures. The chemical and electronic mechanisms for SnO₂ sensor performance have been discussed. We discuss a general analysis of the band structure of the heterojunction formed between the SnO₂ core and shell materials. Recent findings reveal that the photoelectrochemical, photocatalytic and gas sensing properties are enhanced manifold in core–shell SnO₂ nanocrystals. Finally an outlook on the prospects of this research field is given.