Controllable synthesis and enhanced gas sensing properties of a single-crystalline WO3-rGO porous nanocomposite

In this paper, we report on a facile hydrothermal approach combined with a subsequent annealing process for the controllable synthesis of a single-crystalline WO3-rGO porous nanocomposite. The crystal structure, morphology and chemical composition of the as-obtained product were well-characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and Brunauer-Emmett-Teller analysis. The results indicate that this hybrid structure is composed of single-crystal WO3 porous nanoflakes with a size of 500 x 500 nm(2) growing through or anchoring into a sheet-like rGO matrix. We explore the sensing performance of the gas sensor based on the as-synthesized product. Impressively, gas testing shows that the WO3-rGO nanocomposite exhibits an excellent kinetic response speed and good sensitivity toward NO2 and some volatile organic compound pollutants at a low temperature (90 degrees C). The pseudo 3-D structure provides many channels for gas diffusion and clearly enhances sensing properties. As such, this graphene-based composite shows promising potential as a high-performance gas sensing material for real-time gas detection.