Edge-Functionalized Graphene Nanoribbon Chemical Sensor: Comparison with Carbon Nanotube and Graphene

Abstract

With growing focus on the use of carbon nanomaterials in chemical sensors, one-dimensional graphene nanoribbon (GNR) has become one of the most attractive channel materials, owing to its enhanced conductance fluctuation by quantum confinement effects and dense, abundant edge sites. Due to the narrow width of a basal plane with one-dimensional morphology, chemical modification of edge sites would greatly affect the electrical channel properties of a GNR. Here, we demonstrate for the first time that chemically functionalizing the edge sites with aminopropylsilane (APS) molecules can significantly enhance the sensing performance of the GNR sensor. The resulting APSfunctionalized GNR has a sensitivity ((ΔR/R b ) max ) of ∼30% at 0.125 ppm nitrogen dioxide (NO 2 ) and an ultrafast response time (∼6 s), which are, respectively, 7-and 15-fold enhancements compared to a pristine GNR sensor. This is the fastest and most sensitive gas-sensing performance of all GNR sensors reported. To demonstrate the superiority of the GNR-APS sensor, we compare its sensing performance with that of APS-functionalized carbon nanotube (CNT) and reduced graphene oxide (rGO) sensors prepared in identical synthesis conditions. Very interestingly, the GNR-APS sensor exhibited 30-and 93-fold enhanced sensitivity compared to the CNT-APS and rGO-APS sensors. This might be attributed to highly active edge sites with superior chemical reactivity, which are not present in CNT and rGO materials. Density functional theory clearly shows that the greatly enhanced gas response of GNR with edge functionalization can be attributed to the higher electron densities in the highest occupied molecular orbital levels of GNR-APS and incorporation of additional adsorption sites. This finding is the first demonstration of the importance of edge functionalization of GNR for chemical sensors.

Novel electrical properties and applications in kaleidoscopic graphene nanoribbons

“…Edgefunctionalized GNRs have a larger gas response, and GNR-APS sensors also show higher sensitivity, which proves the importance of edge-functionalization of GNRs to chemical sensors. 214 This sensitive sensor material makes GNRs useful for devices such as transistors. Increasing its conductivity by several orders of magnitude is also benecial for sensors.…”

“…Similar sensors include those made of microuidic The relationship between the gas concentration and enhancement factor after APS functionalization. 214 biosensors, nanocomposite network membranes and other nanomaterials. These instruments affect all aspects of our lives: medical blood testing, portable photoelectric equipment, food freshness testing, and drug testing in high-risk environments.…”

“…214 (e) The sensor is the maximum resistance change ((DR/R b ) max (%)) of NO 2 concentration maximum value. 214 (f)The relationship between the gas concentration and enhancement factor after APS functionalization 214.…”

Fjord-Edge Graphene Nanoribbons with Site-Specific Nitrogen Substitution

“…Graphene nanoribbons (GNRs) are expected to usher in the ultimate nanosizing of electronics 1,2,3,4 and sensors 5,6 for next generation devices. The electronic properties of GNRs can be exquisitely tuned by modification of their width, backbone, and edge structure.…”

Direct Laser Writing of Graphene Nanoribbon Thin Films for Supercapacitor Electrodes

“…Various carbon nanomaterials, such as activated carbon, acetylene black, carbon nanotubes, and graphenes, have been utilized as the electrodes of supercapacitors including MSCs. 12 Among those materials, graphene nanoribbons (GNR), quasi-one-dimensional (1D) carbon structures with narrow and elongated strips of graphene, exhibiting relatively high electrical conductivity 13,14 and dense, abundant edge sites 15 are promising for use in supercapacitor electrodes. [16][17][18] In addition, we adopt laser-based, direct writing technology, which is a straightforward, maskless, template-free, and scalable patterning method.…”