More stable structures lead to improved cycle stability in photocatalysis and Li-ion batteries

A simple combustion method was used to synthesize stable network-like nanostructures. Take two kinds of iron oxides for example. The Fe2O3 network nanocrystal with an average diameter of 50 nm composed of Fe grains similar to 5-10 nm in diameter was firstly obtained. It showed an enhanced photocatalysis and cycle stability (similar to 50% after 4 cycles) compared with the commercial NPs (only 24% after 3 cycles) in the degradation of RhB. The structure of the sample could remain even after 4 photocatalytic cycles, explaining why the sample had an improved cyclability. Next, Fe3O4/C network nanostructure was synthesized using Fe2O3 sample as precursor. One Fe3O4 sample with the thickest carbon layers (similar to 8 nm) was more stable, compared to other two samples with similar to 2 nm and similar to 5 nm carbon layers. The related HRTEM image exhibited the outer layers of the sample had become onion-like structure from amorphous carbon, explaining an excellent performance of a capacity of 400 mAh g(-1) after 90 cycles even at a high current rate of 2 C. These two kinds of iron oxide with stable network-like nanostructure by combustion method showed probable applications in photocatalytic and electrochemical fields.