Full-Layer Controlled Synthesis and Transfer of Large-Scale Monolayer Graphene for Nitrogen Dioxide and Ammonia Sensing

The controlled synthesis of large-scale monolayer graphene to be used in the development of cost-effective, mass-produced, and easy-to-use gas sensors for the real time monitoring of toxic gases is an important issue. In this study, scalable monolayer graphene was controllably synthesized by chemical vapor deposition on a copper substrate, and effectively transferred on a silica (insulator) substrate for gas sensing. A high-quality graphene layer was obtained by changing the growth conditions. Raman measurements indicated that large-area (1 × 1 cm2) monolayer graphene dominated the transferred films. Gas sensing characterizations demonstrated that monolayer graphene can effectively detect NO2 and NH3 within the temperature range of 100°C to 200°C. [Supplementary materials are available for this article. Go to the publisher's online edition of Analytical Letters for the following free supplemental resource(s): Additional figures.]