Fabrication of WO3·2H2O nanoplatelet powder by breakdown anodization

Abstract Herein, the electrochemical synthesis of WO 3 nanoplatelet powder is demonstrated in a novel electrolyte composed of ethylene glycol (EG), H 2 O and 1-ethyl-3-methylimidazolium tetrafluoroborate (EmimBF 4 ). On applying an anodization potential of 40 V to the electrolyte at room temperature, the W substrate is efficiently transformed into a dispersed WO 3 ·2H 2 O nanoplatelet powder, not a thin WO 3 film on the W substrate as usually occurs. The interaction between EG and water in the electrolyte during breakdown anodization is discussed, and a mechanism for the formation of WO 3 ·2H 2 O nanoplatelets is proposed.