Unraveling the role of MXene (Ti3C2Tx) integrated Cu-doped WO3 nanocomposites via co-precipitation technique for enhanced supercapacitor performance

Abstract

Abstract The rising population and increased energy consumption drive contemporary researchers to develop highly efficient electrode materials for high-power energy storage devices. Herein, copper-doped tungsten oxide (Cu-WO3) and compositing MXene (Cu-WO3/MXene) in different concentrations have garnered substantial interest for their usage as an electrode material owing to their impressive energy-storing capacity, including high metallic conductivity, hydrophilic nature, and exceptional electrochemical performance due to their active surface chemistry. In the present work, we employ a facile co-precipitation technique to fabricate WO3 and Cu-WO3 (Cu x% = 5 at%, 10 at%, and 15 at%). Furthermore, we synthesized a synergistic 15 at% Cu-WO3/MXene nanocomposite by integrating Cu-WO3 and MXene via sonication. The synthesized sample’s structure, functional, morphology, chemical composition, and electrochemical properties were examined through various techniques such as X-ray powder diffraction (XRD), Fourier transform infrared spectrum (FT-IR), X-ray photoelectron spectra (XPS), Field Emission Scanning Electron Microscopy (FESEM), and High-Resolution Transmission Electron Microscopy (HRTEM). The X-ray diffraction analyses corroborated the monoclinic state of WO3 along with the substitutional inclusion of Cu in the WO3 lattice integrated with MXene. Utilizing a Field Emission Scanning Electron Microscope (FESEM), the surface morphological analysis revealed the formation of Cu-WO3 nanospheres embedded in MXene sheets. Furthermore, according to results obtained from electrochemical analysis profiles, at 1 mA, 15 at% Cu-WO3/MXene displayed a greater specific capacitance of 692.4 F/g in comparison to other electrode materials via a three-electrode system, which is due to the synergistic impact of the Cu-WO3 as well as the conductive properties of MXene sheets. Also, the electrode demonstrated excellent cycling stability, retaining 89% of its initial capacitance over 5000 charge-discharge cycles. The Ragone plot revealed an energy density of 70.10 Wh/kg at a power density of 809.8 W/kg. B-value analysis and scan rate-dependent CV confirmed the contribution of both surface-controlled and diffusion-controlled charge storage mechanisms. Likewise, in contrast to all other synthesized materials, 15 at% Cu-WO3/MXene revealed a lesser solution resistance and charge transfer resistance. In accordance with the results, the 15 at% Cu-WO3/MXene nanocomposite is an extremely efficient capacitive material that can enhance electrochemical performance in energy storage applications.