|
1
|
Casanova-Chafer J, Garcia-Aboal R, Llobet E, Atienzar P. Enhanced CO 2 Sensing by Oxygen Plasma-Treated Perovskite-Graphene Nanocomposites. ACS Sens 2024; 9:830-839. [PMID: 38320174 DOI: 10.1021/acssensors.3c02166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
Carbon dioxide (CO2) is a major greenhouse gas responsible for global warming and climate change. The development of sensitive CO2 sensors is crucial for environmental and industrial applications. This paper presents a novel CO2 sensor based on perovskite nanocrystals immobilized on graphene and functionalized with oxygen plasma treatment. The impact of this post-treatment method was thoroughly investigated using various characterization techniques, including Raman spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The detection of CO2 at parts per million (ppm) levels demonstrated that the hybrids subjected to 5 min of oxygen plasma treatment exhibited a 3-fold improvement in sensing performance compared to untreated layers. Consequently, the CO2 sensing capability of the oxygen-treated samples showed a limit of detection and limit of quantification of 6.9 and 22.9 ppm, respectively. Furthermore, the influence of ambient moisture on the CO2 sensing performance was also evaluated, revealing a significant effect of oxygen plasma treatment.
Collapse
Affiliation(s)
- Juan Casanova-Chafer
- Chimie des Interactions Plasma Surface, Université de Mons, Mons 7000, Belgium
- Universitat Rovira i Virgili, Tarragona 43007, Spain
| | - Rocio Garcia-Aboal
- Instituto de Tecnología Química, CSIC-UPV, Universitat Politècnica de València, Valencia 46022, Spain
| | - Eduard Llobet
- Universitat Rovira i Virgili, Tarragona 43007, Spain
- Research Institute in Sustainability, Climate Change and Energy Transition (IU-RESCAT), Vila-seca 43480, Spain
| | - Pedro Atienzar
- Instituto de Tecnología Química, CSIC-UPV, Universitat Politècnica de València, Valencia 46022, Spain
| |
Collapse
|
|
2
|
Yang L, Xiao W, Wang J, Li XW, Wang L. Improving the HCHO Sensing Selectivity on Ag-Doped Graphene by Oxygen Functionalization: A First-Principles Study. ACS OMEGA 2022; 7:17995-18003. [PMID: 35664580 PMCID: PMC9161398 DOI: 10.1021/acsomega.2c01383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 04/29/2022] [Indexed: 06/15/2023]
Abstract
Graphene-based sensors typically fail in the selectivity of target gas detection when exposed to complex and multicompound atmospheres. We have thoroughly compared the adsorptions of various interfering gases (CO, NH3, CH4, C2H2, C2H4, CH3OH, and CH3Cl) with target HCHO on AgG and AgOG by first-principles simulations. The results demonstrate that AgG shows a poor selectivity for HCHO detection and an oxygen functionalized one can improve the selectivity by enhancing the adsorption strength of HCHO and weakening those of other gas molecules. Moreover, the sensing properties of the AgOG sensors are evaluated by the NEGF method, and the predicted HCHO sensing responses are 76 and 32% along the armchair and zigzag directions, respectively. The present work helps shed some light on designing graphene-based sensing materials with high selectivity.
Collapse
Affiliation(s)
- Lunwei Yang
- State
Key Laboratory of Nonferrous Metals and Processes, GRIMN Group Co., Ltd., Beijing 101417, P. R. China
- GRIMAT
Engineering Institute Co., Ltd., Beijing 100088, P. R.
China
- General
Research Institute for Nonferrous Metals, Beijing 100088, P. R. China
- Department
of Materials Physics and Chemistry, School of Materials Science and
Engineering, Key Laboratory for Anisotropy and Texture of Materials,
Ministry of Education, Northeastern University, Shenyang 110819, P. R. China
| | - Wei Xiao
- State
Key Laboratory of Nonferrous Metals and Processes, GRIMN Group Co., Ltd., Beijing 101417, P. R. China
- GRIMAT
Engineering Institute Co., Ltd., Beijing 100088, P. R.
China
- General
Research Institute for Nonferrous Metals, Beijing 100088, P. R. China
| | - Jianwei Wang
- State
Key Laboratory of Nonferrous Metals and Processes, GRIMN Group Co., Ltd., Beijing 101417, P. R. China
- GRIMAT
Engineering Institute Co., Ltd., Beijing 100088, P. R.
China
- General
Research Institute for Nonferrous Metals, Beijing 100088, P. R. China
| | - Xiao-Wu Li
- Department
of Materials Physics and Chemistry, School of Materials Science and
Engineering, Key Laboratory for Anisotropy and Texture of Materials,
Ministry of Education, Northeastern University, Shenyang 110819, P. R. China
| | - Ligen Wang
- State
Key Laboratory of Nonferrous Metals and Processes, GRIMN Group Co., Ltd., Beijing 101417, P. R. China
- GRIMAT
Engineering Institute Co., Ltd., Beijing 100088, P. R.
China
- General
Research Institute for Nonferrous Metals, Beijing 100088, P. R. China
| |
Collapse
|
|
3
|
Zhang S, Pang J, Li Y, Ibarlucea B, Liu Y, Wang T, Liu X, Peng S, Gemming T, Cheng Q, Liu H, Yang J, Cuniberti G, Zhou W, Rümmeli MH. An effective formaldehyde gas sensor based on oxygen-rich three-dimensional graphene. NANOTECHNOLOGY 2022; 33:185702. [PMID: 35078155 DOI: 10.1088/1361-6528/ac4eb4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 01/24/2022] [Indexed: 06/14/2023]
Abstract
Three-dimensional (3D) graphene with a high specific surface area and excellent electrical conductivity holds extraordinary potential for molecular gas sensing. Gas molecules adsorbed onto graphene serve as electron donors, leading to an increase in conductivity. However, several challenges remain for 3D graphene-based gas sensors, such as slow response and long recovery time. Therefore, research interest remains in the promotion of the sensitivity of molecular gas detection. In this study, we fabricate oxygen plasma-treated 3D graphene for the high-performance gas sensing of formaldehyde. We synthesize large-area, high-quality, 3D graphene over Ni foam by chemical vapor deposition and obtain freestanding 3D graphene foam after Ni etching. We compare three types of strategies-non-treatment, oxygen plasma, and etching in HNO3solution-for the posttreatment of 3D graphene. Eventually, the strategy for oxygen plasma-treated 3D graphene exceeds expectations, which may highlight the general gas sensing based on chemiresistors.
Collapse
Affiliation(s)
- Shu Zhang
- Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of Shandong, Institute for Advanced Interdisciplinary Research (iAIR), University of Jinan, Shandong, Jinan 250022, People's Republic of China
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan, Shandong, Jinan 250022, People's Republic of China
| | - Jinbo Pang
- Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of Shandong, Institute for Advanced Interdisciplinary Research (iAIR), University of Jinan, Shandong, Jinan 250022, People's Republic of China
| | - Yufen Li
- Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of Shandong, Institute for Advanced Interdisciplinary Research (iAIR), University of Jinan, Shandong, Jinan 250022, People's Republic of China
| | - Bergoi Ibarlucea
- Institute for Materials Science and Max Bergmann Center of Biomaterials, Technische Universität Dresden, Dresden D-01069, Germany
- Center for Advancing Electronics Dresden, Technische Universität Dresden, Dresden D-01069, Germany
| | - Yu Liu
- College of Energy, Soochow Institute for Energy and Materials Innovations, Soochow University, Suzhou 215006, People's Republic of China
- Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215006, People's Republic of China
| | - Ting Wang
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, No.3501 Daxue Road, Jinan 250353, People's Republic of China
- School of Bioengineering, Qilu University of Technology, Shandong Academy of Science, Jinan 250353, People's Republic of China
| | - Xiaoyan Liu
- Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of Shandong, Institute for Advanced Interdisciplinary Research (iAIR), University of Jinan, Shandong, Jinan 250022, People's Republic of China
| | - Songang Peng
- High-Frequency High-Voltage Device and Integrated Circuits R&D Center, Institute of Microelectronics, Chinese Academy of Sciences, Beijing, 100029, People's Republic of China
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing, 100029, People's Republic of China
| | - Thomas Gemming
- Institute for Complex Materials, Leibniz Institute for Solid State and Materials Research Dresden, PO Box 270116, Dresden, D-01171 Germany
| | - Qilin Cheng
- Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of Shandong, Institute for Advanced Interdisciplinary Research (iAIR), University of Jinan, Shandong, Jinan 250022, People's Republic of China
| | - Hong Liu
- Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of Shandong, Institute for Advanced Interdisciplinary Research (iAIR), University of Jinan, Shandong, Jinan 250022, People's Republic of China
- State Key Laboratory of Crystal Materials, Center of Bio & Micro/Nano Functional Materials, Shandong University, 27 Shandanan Road, Jinan 250100, People's Republic of China
| | - Jiali Yang
- Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of Shandong, Institute for Advanced Interdisciplinary Research (iAIR), University of Jinan, Shandong, Jinan 250022, People's Republic of China
| | - Gianaurelio Cuniberti
- Institute for Materials Science and Max Bergmann Center of Biomaterials, Technische Universität Dresden, Dresden D-01069, Germany
- Center for Advancing Electronics Dresden, Technische Universität Dresden, Dresden D-01069, Germany
- Dresden Center for Computational Materials Science, Technische Universität Dresden, Dresden D-01062, Germany
- Dresden Center for Intelligent Materials (GCL DCIM), Technische Universität Dresden, Dresden D-01062, Germany
| | - Weijia Zhou
- Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of Shandong, Institute for Advanced Interdisciplinary Research (iAIR), University of Jinan, Shandong, Jinan 250022, People's Republic of China
| | - Mark H Rümmeli
- College of Energy, Soochow Institute for Energy and Materials Innovations, Soochow University, Suzhou 215006, People's Republic of China
- Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215006, People's Republic of China
- Institute for Complex Materials, Leibniz Institute for Solid State and Materials Research Dresden, PO Box 270116, Dresden, D-01171 Germany
- Centre of Polymer and Carbon Materials, Polish Academy of Sciences, M. Curie Sklodowskiej 34, Zabrze 41-819, Poland
- Institute of Environmental Technology (CEET), VŠB-Technical University of Ostrava, 17. Listopadu 15, Ostrava 708 33, Czech Republic
| |
Collapse
|
|
4
|
Mohammed MKA. Synthesis of transparent few layer graphene films using a dual flame approach for the ammonia gas sensor. INORG NANO-MET CHEM 2021. [DOI: 10.1080/24701556.2020.1814336] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
|
5
|
Yuan Y, Wu H, Bu X, Wu Q, Wang X, Han C, Li X, Wang X, Liu W. Improving Ammonia Detecting Performance of Polyaniline Decorated rGO Composite Membrane with GO Doping. MATERIALS 2021; 14:ma14112829. [PMID: 34070649 PMCID: PMC8198450 DOI: 10.3390/ma14112829] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 05/18/2021] [Accepted: 05/19/2021] [Indexed: 12/24/2022]
Abstract
Gas-sensing performance of graphene-based material has been investigated widely in recent years. Polyaniline (PANI) has been reported as an effective method to improve ammonia gas sensors’ response. A gas sensor based on a composite of rGO film and protic acid doped polyaniline (PA-PANI) with GO doping is reported in this work. GO mainly provides NH3 adsorption sites, and PA-PANI is responsible for charge transfer during the gas-sensing response process. The experimental results indicate that the NH3 gas response of rGO is enhanced significantly by decorating with PA-PANI. Moreover, a small amount of GO mixed with PA-PANI is beneficial to increase the gas response, which showed an improvement of 262.5% at 25 ppm comparing to no GO mixing in PA-PANI.
Collapse
Affiliation(s)
- Yubin Yuan
- School of Microelectronics, School of Electronics and Information Engineering, Xi’an Jiaotong University, Xi’an 710049, China; (Y.Y.); (H.W.); (X.B.); (Q.W.); (X.W.); (C.H.); (X.L.); (X.W.)
- The Key Lab of Micro-nano Electronics and System Integration of Xi’an City, Xi’an 710049, China
| | - Haiyang Wu
- School of Microelectronics, School of Electronics and Information Engineering, Xi’an Jiaotong University, Xi’an 710049, China; (Y.Y.); (H.W.); (X.B.); (Q.W.); (X.W.); (C.H.); (X.L.); (X.W.)
- The Key Lab of Micro-nano Electronics and System Integration of Xi’an City, Xi’an 710049, China
| | - Xiangrui Bu
- School of Microelectronics, School of Electronics and Information Engineering, Xi’an Jiaotong University, Xi’an 710049, China; (Y.Y.); (H.W.); (X.B.); (Q.W.); (X.W.); (C.H.); (X.L.); (X.W.)
- The Key Lab of Micro-nano Electronics and System Integration of Xi’an City, Xi’an 710049, China
| | - Qiang Wu
- School of Microelectronics, School of Electronics and Information Engineering, Xi’an Jiaotong University, Xi’an 710049, China; (Y.Y.); (H.W.); (X.B.); (Q.W.); (X.W.); (C.H.); (X.L.); (X.W.)
- The Key Lab of Micro-nano Electronics and System Integration of Xi’an City, Xi’an 710049, China
| | - Xuming Wang
- School of Microelectronics, School of Electronics and Information Engineering, Xi’an Jiaotong University, Xi’an 710049, China; (Y.Y.); (H.W.); (X.B.); (Q.W.); (X.W.); (C.H.); (X.L.); (X.W.)
- The Key Lab of Micro-nano Electronics and System Integration of Xi’an City, Xi’an 710049, China
| | - Chuanyu Han
- School of Microelectronics, School of Electronics and Information Engineering, Xi’an Jiaotong University, Xi’an 710049, China; (Y.Y.); (H.W.); (X.B.); (Q.W.); (X.W.); (C.H.); (X.L.); (X.W.)
- The Key Lab of Micro-nano Electronics and System Integration of Xi’an City, Xi’an 710049, China
| | - Xin Li
- School of Microelectronics, School of Electronics and Information Engineering, Xi’an Jiaotong University, Xi’an 710049, China; (Y.Y.); (H.W.); (X.B.); (Q.W.); (X.W.); (C.H.); (X.L.); (X.W.)
- The Key Lab of Micro-nano Electronics and System Integration of Xi’an City, Xi’an 710049, China
- Guangdong Shunde Xi’an Jiaotong University Academy, Xi’an Jiaotong University, NO.3 Deshengdong Road, Daliang, Shunde District, Foshan 528300, China
| | - Xiaoli Wang
- School of Microelectronics, School of Electronics and Information Engineering, Xi’an Jiaotong University, Xi’an 710049, China; (Y.Y.); (H.W.); (X.B.); (Q.W.); (X.W.); (C.H.); (X.L.); (X.W.)
- The Key Lab of Micro-nano Electronics and System Integration of Xi’an City, Xi’an 710049, China
- School of Science, Xi’an Jiaotong University, Xi’an 710049, China
| | - Weihua Liu
- School of Microelectronics, School of Electronics and Information Engineering, Xi’an Jiaotong University, Xi’an 710049, China; (Y.Y.); (H.W.); (X.B.); (Q.W.); (X.W.); (C.H.); (X.L.); (X.W.)
- The Key Lab of Micro-nano Electronics and System Integration of Xi’an City, Xi’an 710049, China
- Research Institute of Xi’an Jiaotong University, Hangzhou 311215, China
- Correspondence: ; Tel.: +86-29-8266-3343
| |
Collapse
|
|
6
|
Hue NT, Wu Q, Liu W, Bu X, Wu H, Wang C, Li X, Wang X. Graphene oxide/graphene hybrid film with ultrahigh ammonia sensing performance. NANOTECHNOLOGY 2021; 32:115501. [PMID: 33271525 DOI: 10.1088/1361-6528/abd05a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
In this paper, a novel ammonia detection hybrid film is proposed based on a graphene oxide (GO)/graphene stack, which shows excellent sensing characteristics at room temperature. It is attributed to the cooperation of GO layer serving as molecular capture layer while graphene serving as conductive layer. GO layer is obtained on chemical vapor deposited graphene film by a simple drop-casting method. The prepared GO/graphene hybrid film is directly transferred to the target substrate without any additional transfer vehicle to reduce possible contamination. The success of the transfer depends on the mechanical strength of GO layer. The thickness of GO layer can scale down to 55 nm while sustaining the transfer process. The best ammonia gas sensing performance is obtained at about 275 nm GO layer thickness and the ammonia detection limit is calculated to be 1.5 ppb. In conclusion, the ammonia gas sensing performance of GO/graphene hybrid film can be significantly improved through GO layer thickness optimization.
Collapse
Affiliation(s)
- Nguyen The Hue
- Department of Microelectronics, School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Qiang Wu
- Department of Microelectronics, School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Weihua Liu
- Department of Microelectronics, School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Xiangrui Bu
- Department of Microelectronics, School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Haiyang Wu
- Department of Microelectronics, School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Chang Wang
- Department of Microelectronics, School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Xin Li
- Department of Microelectronics, School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Xiaoli Wang
- Department of Microelectronics, School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
- School of Science, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| |
Collapse
|
|
7
|
Preparation and Test of NH 3 Gas Sensor Based on Single-Layer Graphene Film. MICROMACHINES 2020; 11:mi11110965. [PMID: 33126585 PMCID: PMC7693743 DOI: 10.3390/mi11110965] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/26/2020] [Accepted: 10/26/2020] [Indexed: 12/31/2022]
Abstract
The ammonia sensing properties of single-layer graphene synthesized by chemical vapor deposition (CVD) were studied. The Au interdigitated electrode (IDE) was prepared by microelectromechanical systems (MEMS) technology, and then, the single-layer graphene was transferred to the IDE by wet transfer technology. Raman spectroscopy was used to monitor the quality of graphene films transferred to SiO2/Si substrates. Moreover, the theory of graphene’s adsorption of gases is explained. The results show that gas sensing characteristics such as response/recovery time and response are related to the target gas, gas concentration, test temperature, and so on. In the stability test, the difference between the maximum resistance and the minimum resistance of the device is 1 ohm without ammonia, the change is less than 1% of its initial resistance, and the repeatability is up to 98.58%. Therefore, the sensor prepared with high quality single-layer graphene has good repeatability and stability for ammonia detection.
Collapse
|
|
8
|
Casanova-Chafer J, Garcia-Aboal R, Atienzar P, Llobet E. The role of anions and cations in the gas sensing mechanisms of graphene decorated with lead halide perovskite nanocrystals. Chem Commun (Camb) 2020; 56:8956-8959. [PMID: 32638744 DOI: 10.1039/d0cc02984j] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
We report the effects of both anions and cations in lead halide perovskite-graphene hybrids applied to gas sensing. Ultra-fast sensors that can work at room temperature are developed and studied to elucidate the role in the gas sensing mechanisms of different ions in perovskite nanocrystals.
Collapse
|
|
9
|
Seekaew Y, Pon-On W, Wongchoosuk C. Ultrahigh Selective Room-Temperature Ammonia Gas Sensor Based on Tin-Titanium Dioxide/reduced Graphene/Carbon Nanotube Nanocomposites by the Solvothermal Method. ACS OMEGA 2019; 4:16916-16924. [PMID: 31646238 PMCID: PMC6796937 DOI: 10.1021/acsomega.9b02185] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 09/23/2019] [Indexed: 05/27/2023]
Abstract
Resistive-based gas sensors have been considered as the most favorable gas sensors for detection of toxic gases and volatile organic compounds (VOCs) because of their simple structure, low cost, high sensitivity, ease of use, and high stability. Unfortunately, wide application of resistive-based gas sensors is limited by their low selectivity. In this article, we present the fabrication of ultrahigh selective NH3 gas sensor based on tin-titanium dioxide/reduced graphene/carbon nanotube (Sn-TiO2@rGO/CNT) nanocomposites. The Sn-TiO2@rGO/CNT nanocomposites with different molar ratios of Sn/Ti (1:10, 3:10, and 5:10) were synthesized via the solvothermal method. Characterizations by scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy confirmed the decoration of Sn-TiO2 nanoparticles on rGO/CNT nanocomposite surfaces. The Sn-TiO2@rGO/CNT nanocomposite gas sensor exhibited high response and ultrahigh selectivity to NH3 against toluene, dimethylformamide, acetone, ethanol, methanol, isopropanol, formaldehyde, hydrogen, carbon dioxide, acetylene, and VOCs in paint thinners at room temperature. The Sn-TiO2@rGO/CNT nanocomposite gas sensor with molar ratio of Sn/Ti = 1:10 showed the highest response to NH3 over other molar ratios of Sn/Ti as well as pure rGO/CNT and Sn-TiO2 gas sensors. The ammonia-sensing mechanisms of the Sn-TiO2@rGO/CNT gas sensor were proposed based on the formation of p-n heterojunctions of p-type rGO/CNT and n-type Sn-TiO2 nanoparticles via a low-temperature oxidizing reaction process.
Collapse
|