Synergistic effects of multifunctional nanostructured WO3-WS2 decorated on polypyrrole (WO3-WS2/PPy) for the removal of toxic heavy metals from wastewaters and high supercapacitor performance

Abstract

Nowadays, developing a simple, economic, and scalable approach for environmental remediation and producing energy storage devices remains challenging. Herein, we report a novel WO3–WS2 decorated polypyrrole (WO3–WS2/PPy) nanocomposite for the removal of heavy metals, i.e., Cd(II) and Ni(II) and high-performance supercapacitor electrodes.The WO3–WS2/PPy showed significant improvement in the removal of Cd(II) (95.33%) and Ni(II) (89.95%), while WO3–WS2 and PPy revealed removal efficiency of 87.02 and 77.01% for Cd(II) and 82.97 and 74.66% for Ni(II), respectively. For the competitive adsorption experiment, Cu2+/Zn2+ causes a significant influence, while Na+/K+/Mg2+/Ca2+ exerted less effect on the adsorption of the aforementioned metal ions. The WO3–WS2/PPy exhibited higher selectivity toward Cd2+ than Ni2+. Along with, the WO3–WS2 decorated PPy based electrode showed a high specific surface area and support conductive networks, which synergistically improved charge storage capability. The WO3-WS2/PPy-based electrodes exhibit superior electrochemical performance with excellent rate capability, offering the high specific capacitance value of 624 F/g at 3 A/g current density and retaining capacitance stability of 81% after 5000 cycles in 1 M Na2SO4 electrolyte solution. The outcomes of this research infer that WO3-WS2/PPy is a promising candidate for wastewater treatment and high-performance energy storage applications.