Fully printed ethanol transparent paper sensor based on ZnO/rGO nanocomposites

Flexible and easy fabrication gas sensors can be utilized in various applications. In this study, we have proposed and prepared zinc oxide (ZnO) nanorods and reduced grapheme oxide (rGO) nanocomposite materials, fully printed on highly transparent paper substrates, and thoroughly investigated and optimized the performance of these gas sensors to ethanol at room temperature (25 degrees C). Among them, the average length of the ZnO nanorods is 200 nm and the diameter is 30 nm, integrated with rGO, the two-dimensional ZnO/rGO nanocomposites were obtained. The ratios of ZnO and rGO in the materials were controlled, ZnO/rGO nanocomposites ink was prepared, and thin films were coated on paper substrate to acquire transparent flexible paper gas sensors. Furthermore, the fabricated ZnO/rGO paper-based gas sensors achieved ppb grade detection of ethanol at room temperature (25 degrees C) with high performance (favorable selectivity, high gas sensitivity, good stability, and rapid response/recovery time). Specially, the proposed paper-based gas sensors are not only transparent but are also better in breathability, biocompatibility, and biodegradability, which have great application prospects in handheld or wearable electronic devices for the detection of trace ethanol at room temperature.