Simple synthesis of 1D, 2D and 3D WO3 nanostructures on stainless steel substrate for high-performance supercapacitors

Abstract Tungsten oxide (WO 3 ) is a kind of good pseudocapacitive material due to its polyvalent, high theoretical specific capacitance, low cost, excellent electron transport properties and good stability. However, the effect of its morphology on capacitive performance is not so clear yet. Herein, WO 3 nanomaterials with different structures such as WO 3 nanorods (1D structure), nanoplates (2D structure), and microspheres (3D structure) are fabricated on stainless steel substrate by a facile hydrothermal route. The morphologies and structures are characterized by field emission scanning electron microscopy (FESEM), X-Ray Diffraction (XRD), high resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS). Moreover, the supercapacitor performances of as-prepared WO 3 with different structures are investigated systematically. Among these three structures, WO 3 microspheres exhibit the highest gravimetric specific capacitance of 536.72 F/g (the areal capacitance is 751.40 mF/cm 2 ) at a scan rate of 10 mV/s and shows excellent cycle stability (92.3% after 2000 CV cycles) when compared with other structures. This strategy provides the versatile way for design the high performance energy storage devices.