Synthesis of reduced graphene oxide/SnO2 nanosheets/Au nanoparticles ternary composites with enhanced formaldehyde sensing performance

摘要

In this paper, ternary composites composed of reduced graphene oxide (rGO), two dimension (2D) SnO2 nanosheets, and one dimension (OD) Au nanoparticles were successfully synthesized via a facile two-step approach. The rGO/SnO2/Au composites were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), transmission electron microscope (TEM), and X-ray photoelectron spectroscopy (XPS). Characterization results revealed that unique SnO2 nanosheets decorated with Au nanoparticles were homogeneously attached on the surface of rGO. Gas-sensing test results proved that incorporating SnO2 nanosheets with Au nanoparticles and rGO improved the gas-sensing performance toward formaldehyde (HCHO) in terms of lower operating temperature, high sensor response, and good selectivity. The enhanced sensing properties could mainly be attributed to the synergistic effect of ohmic contact between rGO and SnO2 nanosheets, high surface area and strong gas adsorption capacity of sheet-on-sheet heterostructured architectures, and the catalytic effect of Au nanoparticles. This work suggests that the rational design of 0D noble metal nanoparticles, 2D metal oxide nanosheets and 2D rGO to form ternary composites provides an opportunity for achieving high-performance sensing materials.