Ultrasonic-assisted synthesis of Sb2WO6/rGO nanocomposites: structure-optical property relationships and tunable visible-light response

Abstract

Antimony tungstate (Sb₂WO₆)-reduced graphene oxide (rGO) nanocomposites (NCs) with tailored interfacial architecture were synthesized via a facile ultrasonic-assisted hydrothermal approach and characterized systematically. The TEM images show that Sb₂WO₆ nanocrystals are uniformly anchored onto wrinkled rGO nanosheets, forming a highly interconnected hybrid network with intimate interfacial contact. XRD patterns and Raman spectra confirm the preservation of the crystalline Sb₂WO₆ framework and the successful integration of rGO without detectable secondary phases, while XPS analysis verifies the characteristic surface chemical states. Interfacial integration of rGO with Sb₂WO₆ effectively modulated the optical response, leading to enhanced visible-light absorption and a reduction in the optical band gap from 2.72 eV for pristine Sb₂WO₆ to 2.49 eV for the composite containing 10 wt% rGO. The SWO/rGO-10 composite exhibited the lowest PL emission intensity, together with a blue-shifted emission maximum at 461 nm and the broadest emission band (FWHM ≈ 48.02 nm). These findings establish Sb₂WO₆/rGONCs as promising materials for optoelectronic and energy-conversion applications. This work establishes a direct relationship between oxide-carbon interface formation and the optical response of Sb₂WO₆/rGONCs, providing fundamental insights for the design of graphene-integrated oxide heterostructures with tailored optical properties.