Modulating the properties of SnO2 nanocrystals: morphological effects on structural, photoluminescence, photocatalytic, electrochemical and gas sensing properties

Abstract

Tin dioxide (SnO₂) is a material of ever increasing scientific interest as a result of its many useful and varied physical properties: it is a wide band gap (3.6 eV at 300 K), n-type semiconductor which is both highly thermally/chemically stable and inexpensively produced as a highly active nanomaterial. Consequently, it has repeatedly demonstrated promising results in a wide range of applications including gas sensing, lithium batteries, photocatalysis, etc. An interesting facet of SnO₂ research is the ability to tune the nanomaterial's physical properties through controlled synthesis of a target morphology. By modulating the morphologies of SnO₂ nanocrystals it becomes possible to prepare devices that meet new challenges, in particular by development of new ways to selectively tune the morphology in order to manipulate their physical properties, enhancing some and suppressing others, through synthetic strategies. This review article aims to highlight the morphology-dependent properties of SnO₂ nanocrystals and outlines the tools available to tailor their applications. At the outset, general synthetic methodologies are discussed, outlining the selective preparation of a morphologically diverse range of SnO₂ nanostructures and describing the resulting induced physical changes. The impact of these different morphologies on a wide range of applications (photoluminescence, electrochemistry, photocatalysis and gas sensing) is then discussed. Finally, the promising future prospects of this research field are evaluated. The overall aim of this review is to provide an in-depth and rational understanding of the application-based properties of SnO₂ nanocrystals with a primary focus on the systematic enhancement/control of the aforementioned properties through morphological design.