Graphene-wrapped WO₃ nanoparticles with improved performances in electrical conductivity and gas sensing properties

WO₃/graphene (GN) nanocomposites have been successfully synthesized using a facile three-step synthesis. First, an SrWO ₄/graphene oxide (GO) precursor was synthesized by homogeneous precipitation; second, the SrWO₄/GO precursor was transformed into WO₃/GO hybrids by acidification; and third, the WO₃/GO hybrids were reduced to WO₃/GN via UV-assisted photoreduction in water instead of general alcoholic solvent at room temperature. The resulting WO₃ nanoparticles anchored on graphene sheets as spacers to keep the neighboring sheets separated are approximately quadrangular with a side length of 50-200 nm. Compared with WO₃/GO hybrids, WO₃/GN nanocomposites show an enhanced electrical conductivity, which results in an improved gas sensing towards alcohol. This work provides a new insight into the fabrication of tungstate-graphene composites and facilitates their application in future.