Hierarchical WO3 flowers comprising porous single-crystalline nanoplates show enhanced lithium storage and photocatalysis

We report a morphology-conserved transformation approach to successfully synthesize a unique porous WO3 nanoplate assembly, which is hierarchically structured like a flower, from an ammonium tungsten peroxo oxalate containing precursor. The resulting novel, multiple length scale architecture of WO3 and its formation process have been investigated by a series of microscopic, spectroscopic and other techniques. A possible growth mechanism was proposed on the basis of the experiments. When tested as a lithium ion battery anode, the porous WO3 nanoplate assembly showed high rate capacity and high cyclability. Not least, it has also exhibited high photocatalytic activities under visible light irradiation.