Fig. 5
From: Progress in Iron Oxides Based Nanostructures for Applications in Energy Storage
Reprinted with Permission from [74]. Copyright, Wiley-VCH
a–f SEM images of the products (after annealing) at various reaction stages by setting the reaction time. The insets are the corresponding magnified SEM images. The scale bars in the figures and insets are 2 μm and 500 nm, respectively. g Schematic of the formation process of the hierarchically assembled α-Fe2O3/SnO2 nanocomposite.