Template-mediated growth of tungsten oxide with different morphologies for electrochemical application

Abstract The morphology of tungsten oxide (WO3) was effectively mediated by carbon nanotubes (CNTs) as templates. The grown direction of WO3 on the CNT bundle surfaces could be controlled, which mainly depended on the distribution state of tungsten acid (H2WO4) precursor in the reaction system. After thermal treatment of H2WO4/CNTs under nitrogen gas flow, WO3 with different morphologies (plates, short rods, and long rods) and sizes (10-1000 nm) supported by CNT bundles were finally obtained. The results indicated CNT bundles as templates can play an important role in regulating the morphologies of WO3. Moreover, the study shows that CNT bundles exhibit excellent prospects in the tailor-synthesis of micro/nanostructured materials with different dimensions. According to the peak current density for the 1000th electrochemical cycle in 0.5 mol L-1 H2SO4 and 0.5 mol L-1 CH3OH electrolyte solution, short rod-like WO3/CNTs exhibited higher peak current density (43.2 mA cm-2) than long rod-like WO3/CNTs (23.68 mA cm-2), plate-like WO3/CNTs (15.63 mA cm-2), CNTs (2.25 mA cm-2), and commercial WO3 (3.19 mA cm-2). The results demonstrated the potential application of short rod-like WO3/CNTs materials for hydrogen oxidation reaction of methanol fuel cells and in other related fields.