2D/2D Graphene Nanoplatelet-Tungsten Trioxide Hydrate Nanocomposites for Sensing Acetone

The development of miniaturized, low-cost, and highperformance acetone gas sensors is highly desirable for workshop safety management and human health diagnosis. Herein, we present a portable integrated system for real-time detection of acetone concentration based on a novel 2D/2D nanocomposite of tungsten oxide hydrate (WO3.H2O) nanoplates and graphene nanoplatelets (GNPs). The GNP-WO3-H2O nanocomposites were first synthesized using a precipitation process at room temperature with sodium tungstate dihydrate as the precursor and GNP as the template. At low GNP content (0.5 and 1.0 wt %), the GNP-WO3-H2O nano composites exhibited superior sensitivities to the pure WO3-H2O nanoplates. The GNP-WO3-H2O nanocomposite with 1.0 wt % GNP addition could deliver a sensitivity of 6.7 toward 5 ppm acetone, with a fast response time of 7 s. After annealing at 200-400 degrees C, the acetone-sensing performance of both the WO3-H2O nanoplates and GNP-WO3-H2O nanocomposites were obviously deteriorated, which can be attributed to the transformation of WO3-H2O to WO3. Based on the 400 degrees C-annealed GNP-WO3-H2O nanocomposite, a portable integrated system that mainly consists of a controller, an acetone gas sensor, a USB power supply module, and an OLED screen was assembled. The integrated system is capable of monitoring acetone concentration in real time with low energy consumption.