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

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.