Decorating graphene with nanoparticles is an effective method for improving gas selectivity and sensitivity of graphene-based chemical sensors. We report herein the enhancement of the gas selectivity and improved response of a graphene-based chemical sensor by decorating the graphene with synthesized Ag2S nanoparticles. To synthesize uniformly sized Ag2S nanoparticles, we used the ultrasonic irradiation method, and then the synthesized Ag2S nanoparticles were decorated onto graphene uniformly, by using a simple spin coating method. Gas responses of the resulting chemical sensor were tested for volatile organic compounds (VOCs) such as acetone, ethanol, and hexane. While no noticeable gas response changes were obtained for ethanol and hexane vapors, a dramatic increase of ~660% resulted from exposure of the sensor to acetone vapor. In order to determine the mechanism behind the excellent acetone response of graphene decorated with Ag2S nanoparticles, density functional theory (DFT) calculations were performed, and showed higher binding energies and electron transfer between Ag2S and acetone than between Ag2S and the other VOCs. This result indicated that decorating graphene with nanoparticles displaying a high binding energy for the target gas is an efficient way to improve the gas selectivity and response levels of graphene-based chemical sensors.
Bibliographical noteFunding Information:
This research was supported by the Multi-Ministry Collaborative R&D Program (Development of Techniques for Identification and Analysis of Gas Molecules to Protect Against Toxic Substances) through the National Research Foundation of Korea (NRF) funded by KNPA, MSIT, MOTIE, ME, and NFA (NRF-2017M3D9A1073858), and by the Focused Research Program (KK2022-20) of the Korea Research Institute of Chemical Technology (KRICT).
© 2021 The Author(s)
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Physics and Astronomy(all)
- Surfaces and Interfaces
- Surfaces, Coatings and Films