Effect of surfactant on the electrochemical performance of WO3 as supercapacitor electrode

Tungsten oxide (WO3) nanoparticles were synthesized by microwave irradiation method in the presence of cetyltrimethylammonium bromide (CTAB) as a surfactant. The structural, morphological, optical and porous properties were studied. The X-ray diffraction pattern and Raman spectroscopy show that both the sample crystallizes in stable monoclinic structure with nanoplates morphology which is inferred from the image of high-resolution scanning electron microscopy. The use of CTAB as the surfactant decreased the optical band gap of WO3 from 3.27 to 3.24 eV. In addition to which the electrochemical measurements, cyclic voltammetry, chronopotentiometry and electrochemical impedance spectroscopy have been recorded. It is found that the surfactant-mediated WO3 has larger specific surface area, specific capacitance and energy density of 135.90 m2 g−1, 393 F g−1 and 6.69 Wh kg−1, respectively, than the pure WO3. The experimental results revealed that the use of CTAB as surfactant in tungsten oxide synthesis enhanced its electrochemical performance, and thus, it might be a suitable positive electrode material for supercapacitor application.