Hierarchical SnO₂ nanostructures: Recent advances in design, synthesis, and applications

Complex three-dimensional hierarchical structures assembled from well-defined low-dimensional nanosized building blocks are an interesting class of nanomaterials with a rich variety of tunable physicochemical properties. Tin dioxide (SnO₂) is an important n-type wide-bandgap semiconductor with wide applications in transparent conductive films, gas sensors, lithium-ion batteries, and solar cells. In this review, we outline synthetic strategies of hierarchical SnO₂ nanostructures in terms of the dimension and the facet control of their constituting building blocks, creation of porous and hollow structures, as well as their modification by doping and loading with other elements. The design of hierarchical SnO₂ nanostructures with an improved performance in lithium-ion batteries, sensitized solar cells, and gas-sensing applications is reviewed.