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In the current study, an in-situ oxidative polymerization method was used to synthesize polyaniline-coated tungsten trioxide biphasic composite (PANI@WO 3). The as-developed composite material properties were elucidated using different characterization tools such as X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), N 2 sorption-desorption isotherm, and X-ray photoelectron spectroscopy (XPS). The PANI@WO 3 was further applied to remove hexavalent chromium (Cr(VI)) from aqueous solutions. The results demonstrated that the optimal removal efficacy was achieved at pH 2. Meanwhile, the pseudo-second-order kinetic and isotherm of the Langmuir model were fitted for Cr(VI) adsorption. Cr(VI) amount of 549.37 mg·g−1 was the maximum capacity of adsorption attained for PANI@WO 3 , which is significantly higher than that of existing adsorbents. From a thermodynamic point of view, the Cr(VI) adsorption process occurred spontaneously and endothermically. Importantly, PANI@WO 3 still exhibited an excellent adsorption capability after five regeneration cycles, indicating the potential reusability of the PANI@WO 3 composite. XPS analysis of PANI@WO 3 surface after adsorption of Cr(VI) confirmed its adsorption and concomitant reduction into Cr(III) ions. The transfer of mass phenomenon, electrostatic attraction, and reduction reaction were the primary processes for Cr(VI) ions elimination. These findings revealed that the synthesized PANI@WO 3 exhibited a high potential for wastewater treatment containing Cr(VI). [Display omitted] • A novel PANI@WO 3 composite was synthesized and applied for Cr(VI) removal. • PANI@WO 3 nanosorbent provides superior uptake ability for Cr(VI) ions from water. • Cr(VI) ions were electrostatically adsorbed onto PANI@WO 3 and reduced to Cr(III). • PANI@WO 3 exhibits excellent reusability for Cr(VI) ions removal. [ABSTRACT FROM AUTHOR]