Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180-3590, USA.
Sci Rep. 2011;1:166. doi: 10.1038/srep00166. Epub 2011 Nov 23.
Nanostructures are known to be exquisitely sensitive to the chemical environment and offer ultra-high sensitivity for gas-sensing. However, the fabrication and operation of devices that use individual nanostructures for sensing is complex, expensive and suffers from poor reliability due to contamination and large variability from sample-to-sample. By contrast, conventional solid-state and conducting-polymer sensors offer excellent reliability but suffer from reduced sensitivity at room-temperature. Here we report a macro graphene foam-like three-dimensional network which combines the best of both worlds. The walls of the foam are comprised of few-layer graphene sheets resulting in high sensitivity; we demonstrate parts-per-million level detection of NH(3) and NO(2) in air at room-temperature. Further, the foam is a mechanically robust and flexible macro-scale network that is easy to contact (without Lithography) and can rival the durability and affordability of traditional sensors. Moreover, Joule-heating expels chemisorbed molecules from the foam's surface leading to fully-reversible and low-power operation.
纳米结构对化学环境非常敏感，并且在气体传感方面具有超高的灵敏度。然而，使用单个纳米结构进行传感的器件的制造和操作非常复杂、昂贵，并且由于污染和样品间的巨大差异，可靠性较差。相比之下，传统的固态和导电聚合物传感器具有出色的可靠性，但在室温下灵敏度降低。在这里，我们报告了一种宏观的石墨烯泡沫状三维网络，它结合了两者的最佳特性。泡沫的壁由几层石墨烯片组成，因此具有很高的灵敏度；我们在室温下演示了对空气中 NH(3)和 NO(2)的ppm 级检测。此外，该泡沫是一种机械坚固且灵活的宏观网络，易于接触（无需光刻），并且可以与传统传感器的耐用性和价格相媲美。此外，焦耳加热会将化学吸附的分子从泡沫表面排出，从而实现完全可逆和低功耗操作。
