scholarly journals A room-temperature ultrasonic hydrogen sensor based on a sensitive layer of reduced graphene oxide

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xue-Yu Zhang ◽  
Ren-Hao Ma ◽  
Ling-Sheng Li ◽  
Li Fan ◽  
Yue-Tao Yang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Frequency Shift ◽  
Reduced Graphene Oxide ◽  
Room Temperature ◽  
High Sensitivity ◽  
Hydrogen Sensor ◽  
Ultrasonic Sensor ◽  
Sensitive Layer ◽  
Reduced Graphene ◽  
Mass Load

AbstractIt is challenging to increase the sensitivity of a hydrogen sensor operating at room temperature due to weak sorption and tiny mass of hydrogen. In this work, an ultrasonic sensor is presented for detecting hydrogen, which is composed of a 128° YX-LiNbO3 substrate and a reduced graphene oxide (RGO) sensitive layer with a platinum catalyzer. By optimizing the depositing parameters of RGO and platinum, a considerably high sensitivity is achieved at room temperature. A frequency shift of 308.9 kHz is obtained in 100 ppm hydrogen mixed with argon, and a frequency shift of 24.4 kHz is obtained in 1000 ppm hydrogen mixed in synthetic air. It is demonstrated that in addition to strong sorption of the sensitive layer, the coaction of mass load and conductivity variation is key to high sensitivity of the sensor. By establishing the original conductivity of the sensitive layer within the “conductivity window” for enhancing electrical response, we improve the sensitivity of the ultrasonic sensor, which is available for detecting hydrogen with an extremely low concentration of 5 ppm.

scholarly journals Ammonia Gas Detection by Tannic Acid Functionalized and Reduced Graphene Oxide at Room Temperature

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Sweejiang Yoo ◽  
Xin Li ◽  
Yuan Wu ◽  
Weihua Liu ◽  
Xiaoli Wang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Gas Sensor ◽  
Tannic Acid ◽  
Room Temperature ◽  
Gas Sensing ◽  
High Sensitivity ◽  
Gas Detection ◽  
Ammonia Gas ◽  
Reduced Graphene

Reduced graphene oxide (rGO) based chemiresistor gas sensor has received much attention in gas sensing for high sensitivity, room temperature operation, and reversible. Here, for the first time, we present a promising chemiresistor for ammonia gas detection based on tannic acid (TA) functionalized and reduced graphene oxide (rGOTA functionalized). Green reductant of TA plays a major role in both reducing process and enhancing the gas sensing properties ofrGOTA functionalized. Our results showrGOTA functionalizedonly selective to ammonia with excellent respond, recovery, respond time, and recovery times.rGOTA functionalizedelectrical resistance decreases upon exposure to NH3where we postulated that it is due to n-doping by TA and charge transfer betweenrGOTA functionalizedand NH3through hydrogen bonding. Furthermore,rGOTA functionalizedhinders the needs for stimulus for both recovery and respond. The combination of greener sensing material and simplicity in overall sensor design provides a new sight for green reductant approach of rGO based chemiresistor gas sensor.

Fe3O4/rGO nanocomposite: synthesis and enhanced NOxgas-sensing properties at room temperature

RSC Advances ◽  
2016 ◽  
Vol 6 (43) ◽  
pp. 37085-37092 ◽  
Author(s):  
Ying Yang ◽  
Li Sun ◽  
Xiangting Dong ◽  
Hui Yu ◽  
Tingting Wang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Detection Limit ◽  
Response Time ◽  
Reduced Graphene Oxide ◽  
Room Temperature ◽  
Gas Sensing ◽  
High Sensitivity ◽  
Short Response Time ◽  
Reduced Graphene ◽  
Sensing Performance

Fe3O4nanoparticles-decorated reduced graphene oxide nanocomposites have been successfully synthesized using solvothermal-pyrolytic method. They have superior gas sensing performance with low detection limit, high sensitivity and short response time.

Enhanced NO2 sensing performance of reduced graphene oxide by in situ anchoring carbon dots

2017 ◽  
Vol 5 (27) ◽  
pp. 6862-6871 ◽  
Author(s):  
Jing Hu ◽  
Cheng Zou ◽  
Yanjie Su ◽  
Ming Li ◽  
Nantao Hu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Gas Sensor ◽  
Carbon Dots ◽  
Room Temperature ◽  
Low Cost ◽  
High Sensitivity ◽  
Reduced Graphene ◽  
Sensing Performance

A room-temperature NO2 gas sensor of high sensitivity, selectivity and stability based on a low-cost, all-carbon nanoscale heterostructure and eco-friendly 2D rGO–CD hybrids.

Polyaniline-Reduced Graphene Oxide Nanosheets for Room Temperature NH3 Detection

2021 ◽  
Author(s):  
Junyu Chang ◽  
Xiaobo Zhang ◽  
Zhenming Wang ◽  
Chunsheng Li ◽  
Qi Hu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Room Temperature ◽  
Graphene Oxide Nanosheets ◽  
Reduced Graphene

scholarly journals Functionalized Reduced Graphene Oxide Thin Films for Ultrahigh CO2 Gas Sensing Performance at Room Temperature

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 623
Author(s):  
Monika Gupta ◽  
Huzein Fahmi Hawari ◽  
Pradeep Kumar ◽  
Zainal Arif Burhanudin ◽  
Nelson Tansu
Keyword(s):  
Thin Films ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Gas Sensor ◽  
Functional Groups ◽  
Recovery Time ◽  
Room Temperature ◽  
Co2 Gas ◽  
Reduced Graphene ◽  
Response And Recovery

The demand for carbon dioxide (CO2) gas detection is increasing nowadays. However, its fast detection at room temperature (RT) is a major challenge. Graphene is found to be the most promising sensing material for RT detection, owing to its high surface area and electrical conductivity. In this work, we report a highly edge functionalized chemically synthesized reduced graphene oxide (rGO) thin films to achieve fast sensing response for CO2 gas at room temperature. The high amount of edge functional groups is prominent for the sorption of CO2 molecules. Initially, rGO is synthesized by reduction of GO using ascorbic acid (AA) as a reducing agent. Three different concentrations of rGO are prepared using three AA concentrations (25, 50, and 100 mg) to optimize the material properties such as functional groups and conductivity. Thin films of three different AA reduced rGO suspensions (AArGO25, AArGO50, AArGO100) are developed and later analyzed using standard FTIR, XRD, Raman, XPS, TEM, SEM, and four-point probe measurement techniques. We find that the highest edge functionality is achieved by the AArGO25 sample with a conductivity of ~1389 S/cm. The functionalized AArGO25 gas sensor shows recordable high sensing properties (response and recovery time) with good repeatability for CO2 at room temperature at 500 ppm and 50 ppm. Short response and recovery time of ~26 s and ~10 s, respectively, are achieved for 500 ppm CO2 gas with the sensitivity of ~50 Hz/µg. We believe that a highly functionalized AArGO CO2 gas sensor could be applicable for enhanced oil recovery, industrial and domestic safety applications.

Sign in / Sign up

Export Citation Format

Share Document