Morphology optimization of CVD graphene decorated with Ag nanoparticles as ammonia sensor

Self Cite

A hybrid structure gas sensor of reduced graphene oxide (RGO) decorated graphene (RGO-Gr) is designed for ultra-low concentration ammonia detection. The resistance value of the RGO-Gr hybrid is the indicator of the ammonia concentration and controlled by effective charge transport from RGO to graphene after ammonia molecule adsorption. In this hybrid material, RGO is the adsorbing layer to catch ammonia molecules and graphene is the conductive layer to effectively enhance charge/electron transport. Compared to a RGO gas sensor, the signal-to-noise ratio (SNR) of the RGO-Gr is increased from 22 to 1008. Meanwhile, the response of the RGO-Gr gas sensor is better than that of either a pristine graphene or RGO gas sensor. It is found that the RGO reduction time is related to the content of functional groups that directly reflect on the gas sensing properties of the sensor. The RGO-Gr gas sensor with 10 min reduction time has the best gas sensing properties in this type of sensor. The highest sensitivity is 2.88% towards 0.5 ppm, and the ammonia gas detection limit is calculated to be 36 ppb.

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A Reduced GO-Graphene Hybrid Gas Sensor for Ultra-Low Concentration Ammonia Detection

Wang

Lei

et al. 2018

Self Cite

“…The performance of the sensor in this work was also compared with other types of NH 3 sensors based on decorated graphene, RGO, metal oxide (MO X ), etc. in Table S1 in Supplementary Information [42,43,44,45,46,47,48,49]. As shown in Table S1, our OP-G/G based sensor showed improved performance in response and recovery compared with graphene based NH 3 sensors in other reports.…”

Section: Resultsmentioning

confidence: 60%

A Gas Sensing Channel Composited with Pristine and Oxygen Plasma-Treated Graphene

Deng³

et al. 2019

Self Cite

Oxygen plasma treatment has been reported as an effective way of improving the response of graphene gas sensors. In this work, a gas sensor based on a composite graphene channel with a layer of pristine graphene (G) at the bottom and an oxygen plasma-treated graphene (OP-G) as a covering layer was reported. The OP-G on top provided oxygen functional groups and serves as the gas molecule grippers, while the as-grown graphene beneath serves as a fast carrier transport path. Thus, the composite channel (OP-G/G) demonstrated significantly improved response in NH3 gas sensing tests compared with the pristine G channel. Moreover, the OP-G/G channel showed faster response and recovering process than the OP-G channel. Since this kind of composite channel is fabricated from chemical vapor deposited graphene and patterned with standard photolithography, the device dimension was much smaller than a gas sensor fabricated from reduced graphene oxide and it is favorable for the integration of a large number of sensing units.

“…This sensor exhibited fast response/recovery of 5 s and great selectivity compared to CO, CO 2 , and H 2 at room temperature. Gautam et al [ 84 ] and Song et al [ 85 ] also presented the CVD-G sensors functionalized by Ag and Au, respectively, for NH 3 detection. The other functionalization methods of metallic nanoparticles can be found in reference [ 86 ].…”

Section: Functionalized Graphene Nh 3 Sensorsmentioning

confidence: 99%

A Review on Functionalized Graphene Sensors for Detection of Ammonia

Tang

Debliquy

Lahem

et al. 2021

Since the first graphene gas sensor has been reported, functionalized graphene gas sensors have already attracted a lot of research interest due to their potential for high sensitivity, great selectivity, and fast detection of various gases. In this paper, we summarize the recent development and progression of functionalized graphene sensors for ammonia (NH3) detection at room temperature. We review graphene gas sensors functionalized by different materials, including metallic nanoparticles, metal oxides, organic molecules, and conducting polymers. The various sensing mechanism of functionalized graphene gas sensors are explained and compared. Meanwhile, some existing challenges that may hinder the sensor mass production are discussed and several related solutions are proposed. Possible opportunities and perspective applications of the graphene NH3 sensors are also presented.