Facile microwave synthesis of Sn-doped WO3 for pseudocapacitor applications

In the present work, we have successfully synthesized pure tungsten oxide (WO3) and Sn (3 and 5 wt%)-doped WO3 nanoparticles using facile microwave irradiation method and studied about the electrochemical performances for supercapacitor electrode material. Structural and morphological studies of the prepared nanomaterials were investigated systematically. The powder XRD analysis reveals that pure WO3 and Sn-doped WO3 have monoclinic crystal structure and also crystallite size of the material decreases from 38 to 30 nm with increasing dopant concentration. Micro-Raman analysis confirms the formation of monoclinic phase with upsilon(O-W-O) stretching and delta(O-W-O) bending mode of vibration. SEM and micrographs show the elongation of the plate-like nanostructure of WO3 for the doping of Sn. High-resolution transmission electron microscope images depict the morphological change and increased porosity in doped samples. The supercapacitive performance and the electrochemical conductivity of the samples were analysed using cyclic voltammetry, chronopotentiometry and electrochemical impedance spectroscopy measurements. The results demonstrate that the 5 wt% Sn-doped WO3 electrode has the enhanced electrochemical performance in 1 M KOH with a maximum specific capacitance of 418 F g(-1) at low current density of 1 A g(-1). Also, it shows the increase in energy density from 4.88 to 11.77 Wh kg(-1) with respect to the Sn concentration at the power density of 225 W kg(.)(-1)

Automated summary

The study successfully synthesized pure tungsten oxide and Sn-doped tungsten oxide nanoparticles, investigating the structural and morphological changes, as well as the electrochemical performance. The presence of Sn dopant resulted in a decrease in crystal size and formation of monoclinic crystal structure in WO3 nanoparticles, impacting its structure and morphology. Further electrochemical tests demonstrated that the 5 wt% Sn-doped WO3 sample exhibited enhanced performance in 1 M KOH electrolyte compared to pure WO3.