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Zhang X, Zhou Y, Chen Y, Li M, Yu H, Li X. Advanced In Situ TEM Microchip with Excellent Temperature Uniformity and High Spatial Resolution. SENSORS (BASEL, SWITZERLAND) 2023; 23:s23094470. [PMID: 37177673 PMCID: PMC10181734 DOI: 10.3390/s23094470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 04/22/2023] [Accepted: 04/29/2023] [Indexed: 05/15/2023]
Abstract
Transmission electron microscopy (TEM) is a highly effective method for scientific research, providing comprehensive analysis and characterization. However, traditional TEM is limited to observing static material structures at room temperature within a high-vacuum environment. To address this limitation, a microchip was developed for in situ TEM characterization, enabling the real-time study of material structure evolution and chemical process mechanisms. This microchip, based on microelectromechanical System (MEMS) technology, is capable of introducing multi-physics stimulation and can be used in conjunction with TEM to investigate the dynamic changes of matter in gas and high-temperature environments. The microchip design ensures a high-temperature uniformity in the sample observation area, and a system of tests was established to verify its performance. Results show that the temperature uniformity of 10 real-time observation windows with a total area of up to 1130 μm2 exceeded 95%, and the spatial resolution reached the lattice level, even in a flowing atmosphere of 1 bar.
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Affiliation(s)
- Xuelin Zhang
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- School of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yufan Zhou
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- School of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ying Chen
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- School of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ming Li
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- School of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Haitao Yu
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- School of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xinxin Li
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- School of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
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Tang Y, Gong J, Gou Y, Wang H, Yu L. The CeO2–TiO2 composite material for improving response speed of detecting low-concentration formaldehyde. APPLIED NANOSCIENCE 2022. [DOI: 10.1007/s13204-022-02607-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
Nanostructured titanium compounds have recently been applied in the design of gas sensors. Among titanium compounds, titanium oxides (TiO2) are the most frequently used in gas sensing devices. Therefore, in this review, we are paying significant attention to the variety of allotropic modifications of titanium oxides, which include anatase, rutile, brukite. Very recently, the applicability of non-stoichiometric titanium oxide (TiO2−x)-based layers for the design of gas sensors was demonstrated. For this reason, in this review, we are addressing some research related to the formation of non-stoichiometric titanium oxide (TiO2−x) and Magnéli phase (TinO2n−1)-based layers suitable for sensor design. The most promising titanium compounds and hetero- and nano-structures based on these compounds are discussed. It is also outlined that during the past decade, many new strategies for the synthesis of TiO2 and conducting polymer-based composite materials were developed, which have found some specific application areas. Therefore, in this review, we are highlighting how specific formation methods, which can be used for the formation of TiO2 and conducting polymer composites, can be applied to tune composite characteristics that are leading towards advanced applications in these specific technological fields. The possibility to tune the sensitivity and selectivity of titanium compound-based sensing layers is addressed. In this review, some other recent reviews related to the development of sensors based on titanium oxides are overviewed. Some designs of titanium-based nanomaterials used for the development of sensors are outlined.
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4
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Design and optimization strategies of metal oxide semiconductor nanostructures for advanced formaldehyde sensors. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2021.214280] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Goncharov T, Nasriddinov A, Zubenko A, Tokarev S, Shatalova T, Khmelevsky N, Fedorova O, Rumyantseva M. Nanocrystalline SnO 2 Functionalized with Ag(I) Organometallic Complexes as Materials for Low Temperature H 2S Detection. MATERIALS (BASEL, SWITZERLAND) 2021; 14:7778. [PMID: 34947372 PMCID: PMC8707773 DOI: 10.3390/ma14247778] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 12/09/2021] [Accepted: 12/13/2021] [Indexed: 11/16/2022]
Abstract
This paper presents a comparative analysis of H2S sensor properties of nanocrystalline SnO2 modified with Ag nanoparticles (AgNPs) as reference sample or Ag organic complexes (AgL1 and AgL2). New hybrid materials based on SnO2 and Ag(I) organometallic complexes were obtained. The microstructure, compositional characteristics and thermal stability of the composites were thoroughly studied by X-ray diffraction (XRD), X-ray fluorescent spectroscopy (XRF), Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and Thermogravimetric analysis (TGA). Gas sensor properties to 2 ppm H2S demonstrated high sensitivity, selectivity toward other reducing gases (H2 (20 ppm), NH3 (20 ppm) and CO (20 ppm)) and good reproducibility of the composites in H2S detection at low operating temperatures. The composite materials also showed a linear detection range in the concentration range of 0.12-2.00 ppm H2S even at room temperature. It was concluded that the predominant factors influencing the sensor properties and selectivity toward H2S in low temperature region are the structure of the modifier and the chemical state of silver. Thus, in the case of SnO2/AgNPs reference sample the chemical sensitization mechanism is more possible, while for SnO2/AgL1 and SnO2/AgL2 composites the electronic sensitization mechanism contributes more in gas sensor properties. The obtained results show that composites based on nanocrystalline SnO2 and Ag(I) organic complexes can enhance the selective detection of H2S.
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Affiliation(s)
- Timofei Goncharov
- Faculty of Materials Science, Moscow State University, 119991 Moscow, Russia; (T.G.); (A.N.)
| | - Abulkosim Nasriddinov
- Faculty of Materials Science, Moscow State University, 119991 Moscow, Russia; (T.G.); (A.N.)
- Chemistry Department, Moscow State University, 119991 Moscow, Russia;
| | - Anastasia Zubenko
- A.N. Nesmeyanov Institute of Organoelement Compounds RAS, 119991 Moscow, Russia; (A.Z.); (S.T.); (O.F.)
| | - Sergey Tokarev
- A.N. Nesmeyanov Institute of Organoelement Compounds RAS, 119991 Moscow, Russia; (A.Z.); (S.T.); (O.F.)
| | - Tatyana Shatalova
- Chemistry Department, Moscow State University, 119991 Moscow, Russia;
| | - Nikolay Khmelevsky
- LISM, Moscow State Technological University Stankin, 127055 Moscow, Russia;
| | - Olga Fedorova
- A.N. Nesmeyanov Institute of Organoelement Compounds RAS, 119991 Moscow, Russia; (A.Z.); (S.T.); (O.F.)
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Gas sensors based on TiO2 nanostructured materials for the detection of hazardous gases: A review. NANO MATERIALS SCIENCE 2021. [DOI: 10.1016/j.nanoms.2021.05.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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7
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Nasriddinov A, Platonov V, Garshev A, Rumyantseva M. Low Temperature HCHO Detection by SnO 2/TiO 2@Au and SnO 2/TiO 2@Pt: Understanding by In-Situ DRIFT Spectroscopy. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:2049. [PMID: 34443880 PMCID: PMC8398349 DOI: 10.3390/nano11082049] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 08/06/2021] [Accepted: 08/09/2021] [Indexed: 12/31/2022]
Abstract
In this work we analyze the effectiveness of decoration of nanocrystalline SnO2/TiO2 composites with gold nanoparticles (Au NPs) and platinum nanoparticles (Pt NPs) in enhancing gas sensor properties in low-temperature HCHO detection. Nanocrystalline SnO2/TiO2 composites were synthesized by a chemical precipitation method with following modification with Pt and Au NPs by the impregnation method. The nanocomposites were characterized by TEM, XRD, Raman and FTIR spectroscopy, DRIFTS, XPS, TPR-H2 methods. In HCHO detection, the modification of SnO2 with TiO2 leads to a shift in the optimal temperature from 150 to 100 °C. Further modification of SnO2/TiO2 nanocomposites with Au NPs increases the sensor signal at T = 100 °C, while modification with Pt NPs gives rise to the appearance of sensor responses at T = 25 °C and 50 °C. At 200 °C nanocomposites exhibited high selectivity toward formaldehyde within the sub-ppm concentration range among different VOCs. The influence of Pt and Au NPs on surface reactivity of SnO2/TiO2 composite and enhancement of the sensor response toward HCHO was studied by DRIFT spectroscopy and explained by the chemical and electronic sensitization mechanisms.
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Affiliation(s)
- Abulkosim Nasriddinov
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1-3, 119991 Moscow, Russia; (A.N.); (V.P.); (A.G.)
- Department of Materials Science, Lomonosov Moscow State University, Leninskie Gory 1-3, 119991 Moscow, Russia
| | - Vadim Platonov
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1-3, 119991 Moscow, Russia; (A.N.); (V.P.); (A.G.)
| | - Alexey Garshev
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1-3, 119991 Moscow, Russia; (A.N.); (V.P.); (A.G.)
- Department of Materials Science, Lomonosov Moscow State University, Leninskie Gory 1-3, 119991 Moscow, Russia
| | - Marina Rumyantseva
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1-3, 119991 Moscow, Russia; (A.N.); (V.P.); (A.G.)
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8
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Strategies for Improving the Sensing Performance of Semiconductor Gas Sensors for High-Performance Formaldehyde Detection: A Review. CHEMOSENSORS 2021. [DOI: 10.3390/chemosensors9070179] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Formaldehyde is a poisonous and harmful gas, which is ubiquitous in our daily life. Long-term exposure to formaldehyde harms human body functions; therefore, it is urgent to fabricate sensors for the real-time monitoring of formaldehyde concentrations. Metal oxide semiconductor (MOS) gas sensors is favored by researchers as a result of their low cost, simple operation and portability. In this paper, the mechanism of formaldehyde detection by gas sensors is introduced, and then the ways of ameliorating the response of gas sensors for formaldehyde detection in recent years are summarized. These methods include the control of the microstructure and morphology of sensing materials, the doping modification of matrix materials, the development of new semiconductor sensing materials, the outfield control strategy and the construction of the filter membrane. These five methods will provide a good prerequisite for the preparation of better performing formaldehyde gas sensors.
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9
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Tang Y, Zhang M, Nawaz SA, Tian X, Wang H, Wang J. TiO 2hierarchical nano blooming-flower decorated by Pt for formaldehyde detection. NANOTECHNOLOGY 2021; 32:365601. [PMID: 34038880 DOI: 10.1088/1361-6528/ac056c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 05/26/2021] [Indexed: 06/12/2023]
Abstract
To achieve an ultra-low concentration formaldehyde detection at low temperature, a platinum (Pt) assisted TiO2hierarchical nano blooming-flower sphere material is synthesized through hydrothermal method. SEM and transmission electron microscope characterizations show that the diameter of the nano sphere was around 2μm with dissilient rods of 60 nm in diameter and 1μm in length on the surface. The response (Ra/Rg) achieved form this nanomaterial to HCHO is 1.08 (100 ppb) and 5.82 (5 ppm) at 130 °C without an involvement of any light source or solution. The relationship curve between the responses and concentrations shows regular exponential trend. The verification of sensor stability done by a 3 month reliability test shows no response-degradation. The optimal response and stability is attributed to the massive dissilient rods on the surface of TiO2spheres and the assistance of Pt as a catalyzer disperses to intensify the formation of depletion area on the surface of TiO2. This study provide an attractive and cost effective solution for the detection of HCHO in air at a relatively low temperature.
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Affiliation(s)
- Yankun Tang
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, People's Republic of China
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, People's Republic of China
| | - Ming Zhang
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, People's Republic of China
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, People's Republic of China
| | - Sher Ali Nawaz
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, People's Republic of China
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, People's Republic of China
| | - Xianqing Tian
- China Academy of Engineering Physics, Institute of Chemical Materials, 64 Mianshan Road, Mianyang, Sichuan, 621900, People's Republic of China
| | - Hairong Wang
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, People's Republic of China
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, People's Republic of China
| | - Jiuhong Wang
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, People's Republic of China
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10
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Chizhov A, Rumyantseva M, Gaskov A. Light Activation of Nanocrystalline Metal Oxides for Gas Sensing: Principles, Achievements, Challenges. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:892. [PMID: 33807340 PMCID: PMC8066598 DOI: 10.3390/nano11040892] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 03/22/2021] [Accepted: 03/24/2021] [Indexed: 11/16/2022]
Abstract
The review deals with issues related to the principle of operation of resistive semiconductor gas sensors and the use of light activation instead of thermal heating when detecting gases. Information on the photoelectric and optical properties of nanocrystalline oxides SnO2, ZnO, In2O3, and WO3, which are the most widely used sensitive materials for semiconductor gas sensors, is presented. The activation of the gas sensitivity of semiconductor materials by both UV and visible light is considered. When activated by UV light, the typical approaches for creating materials are (i) the use of individual metal oxides, (ii) chemical modification with nanoparticles of noble metals and their oxides, (iii) and the creation of nanocomposite materials based on metal oxides. In the case of visible light activation, the approaches used to enhance the photo- and gas sensitivity of wide-gap metal oxides are (i) doping; (ii) spectral sensitization using dyes, narrow-gap semiconductor particles, and quantum dots; and (iii) addition of plasmon nanoparticles. Next, approaches to the description of the mechanism of the sensor response of semiconductor sensors under the action of light are considered.
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Affiliation(s)
| | - Marina Rumyantseva
- Chemistry Department, Moscow State University, 119991 Moscow, Russia; (A.C.); (A.G.)
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Yue X, Ma NL, Sonne C, Guan R, Lam SS, Van Le Q, Chen X, Yang Y, Gu H, Rinklebe J, Peng W. Mitigation of indoor air pollution: A review of recent advances in adsorption materials and catalytic oxidation. JOURNAL OF HAZARDOUS MATERIALS 2021; 405:124138. [PMID: 33092884 DOI: 10.1016/j.jhazmat.2020.124138] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 09/07/2020] [Accepted: 09/27/2020] [Indexed: 06/11/2023]
Abstract
Indoor air pollution with toxic volatile organic compounds (VOCs) and fine particulate matter (PM2.5) is a threat to human health, causing cancer, leukemia, fetal malformation, and abortion. Therefore, the development of technologies to mitigate indoor air pollution is important to avoid adverse effects. Adsorption and photocatalytic oxidation are the current approaches for the removal of VOCs and PM2.5 with high efficiency. In this review we focus on the recent development of indoor air pollution mitigation materials based on adsorption and photocatalytic decomposition. First, we review on the primary indoor air pollutants including formaldehyde, benzene compounds, PM2.5, flame retardants, and plasticizer: Next, the recent advances in the use of adsorption materials including traditional biochar and MOF (metal-organic frameworks) as the new emerging porous materials for VOCs absorption is reviewed. We review the mechanism for mitigation of VOCs using biochar (noncarbonized organic matter partition and adsorption) and MOF together with parameters that affect indoor air pollution removal efficiency based on current mitigation approaches including the mitigation of VOCs using photocatalytic oxidation. Finally, we bring forward perspectives and directions for the development of indoor air mitigation technologies.
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Affiliation(s)
- Xiaochen Yue
- Henan Province Engineering Research Center for Biomass Value-added Products, School of Forestry, Henan Agricultural University, Zhengzhou 450002, China
| | - Nyuk Ling Ma
- Universiti Malaysia Terengganu, Fac Sci & Marine Environm, Terengganu 21030, Malaysia
| | - Christian Sonne
- Henan Province Engineering Research Center for Biomass Value-added Products, School of Forestry, Henan Agricultural University, Zhengzhou 450002, China; Aarhus University, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark
| | - Ruirui Guan
- Henan Province Engineering Research Center for Biomass Value-added Products, School of Forestry, Henan Agricultural University, Zhengzhou 450002, China
| | - Su Shiung Lam
- Pyrolysis Technology Research Group, Institute of Tropical Aquaculture and Fisheries (AKUATROP), Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia
| | - Quyet Van Le
- Institute of Research and Development, Duy Tan University, Da Nang 550000, Vietnam
| | - Xiangmeng Chen
- School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou 450001, China
| | - Yafeng Yang
- Henan Province Engineering Research Center for Biomass Value-added Products, School of Forestry, Henan Agricultural University, Zhengzhou 450002, China
| | - Haiping Gu
- Henan Province Engineering Research Center for Biomass Value-added Products, School of Forestry, Henan Agricultural University, Zhengzhou 450002, China
| | - Jörg Rinklebe
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water, and Waste-Management, Soil, and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany; Department of Environment, Department of Environment and Energy, Sejong University, Seoul 05006, Republic of Korea
| | - Wanxi Peng
- Henan Province Engineering Research Center for Biomass Value-added Products, School of Forestry, Henan Agricultural University, Zhengzhou 450002, China.
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Shellaiah M, Sun KW. Inorganic-Diverse Nanostructured Materials for Volatile Organic Compound Sensing. SENSORS (BASEL, SWITZERLAND) 2021; 21:633. [PMID: 33477501 PMCID: PMC7831086 DOI: 10.3390/s21020633] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/05/2021] [Accepted: 01/14/2021] [Indexed: 11/17/2022]
Abstract
Environmental pollution related to volatile organic compounds (VOCs) has become a global issue which attracts intensive work towards their controlling and monitoring. To this direction various regulations and research towards VOCs detection have been laid down and conducted by many countries. Distinct devices are proposed to monitor the VOCs pollution. Among them, chemiresistor devices comprised of inorganic-semiconducting materials with diverse nanostructures are most attractive because they are cost-effective and eco-friendly. These diverse nanostructured materials-based devices are usually made up of nanoparticles, nanowires/rods, nanocrystals, nanotubes, nanocages, nanocubes, nanocomposites, etc. They can be employed in monitoring the VOCs present in the reliable sources. This review outlines the device-based VOC detection using diverse semiconducting-nanostructured materials and covers more than 340 references that have been published since 2016.
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Affiliation(s)
| | - Kien Wen Sun
- Department of Applied Chemistry, National Chiao Tung University, Hsinchu 30010, Taiwan;
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Ramanavicius S, Ramanavicius A. Insights in the Application of Stoichiometric and Non-Stoichiometric Titanium Oxides for the Design of Sensors for the Determination of Gases and VOCs (TiO 2-x and Ti nO 2n-1 vs. TiO 2). SENSORS (BASEL, SWITZERLAND) 2020; 20:E6833. [PMID: 33260465 PMCID: PMC7730008 DOI: 10.3390/s20236833] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 11/23/2020] [Accepted: 11/24/2020] [Indexed: 11/18/2022]
Abstract
In this review article, attention is paid towards the formation of various nanostructured stoichiometric titanium dioxide (TiO2), non-stoichiometric titanium oxide (TiO2-x) and Magnéli phase (TinO2n-1)-based layers, which are suitable for the application in gas and volatile organic compound (VOC) sensors. Some aspects related to variation of sensitivity and selectivity of titanium oxide-based sensors are critically overviewed and discussed. The most promising titanium oxide-based hetero- and nano-structures are outlined. Recent research and many recently available reviews on TiO2-based sensors and some TiO2 synthesis methods are discussed. Some promising directions for the development of TiO2-based sensors, especially those that are capable to operate at relatively low temperatures, are outlined. The applicability of non-stoichiometric titanium oxides in the development of gas and VOC sensors is foreseen and transitions between various titanium oxide states are discussed. The presence of non-stoichiometric titanium oxide and Magnéli phase (TinO2n-1)-based layers in 'self-heating' sensors is predicted, and the advantages and limitations of 'self-heating' gas and VOC sensors, based on TiO2 and TiO2-x/TiO2 heterostructures, are discussed.
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Affiliation(s)
- Simonas Ramanavicius
- Department of Electrochemical Material Science, State Research Institute Center for Physical Sciences and Technology (FTMC), Sauletekio av. 3, LT-10257 Vilnius, Lithuania;
- Department of Physical Chemistry, Faculty of Chemistry and Geosciences, Institute of Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius, Lithuania
| | - Arunas Ramanavicius
- Department of Physical Chemistry, Faculty of Chemistry and Geosciences, Institute of Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius, Lithuania
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Formaldehyde and Total VOC (TVOC) Commercial Low-Cost Monitoring Devices: From an Evaluation in Controlled Conditions to a Use Case Application in a Real Building. CHEMOSENSORS 2020. [DOI: 10.3390/chemosensors8010008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Formaldehyde and volatile organic compounds (VOCs) are major indoor pollutants with multiple origins. Standard methods exist to measure them that require analytical expertise and provide, at best, an average value of their concentrations. There is a need to monitor them continuously during periods of several days, weeks, or even months. Recently, portable devices have become available. Two categories of portable devices are considered in this research paper: connected objects for the general public (price <500 €) and monitoring portable devices for professional users (price in the range >500 to 5000 €). The ISO method (ISO 16000-29) describes the standard for VOC detector qualification. It is quite complex and is not well adapted for a first qualitative evaluation of these low-cost devices. In this paper, we present an experimental methodology used to evaluate commercial devices that monitor formaldehyde and/or total volatile organic compounds (TVOC) under controlled conditions (23 °C, 50–65% relative humidity (RH)). We conclude that none of the connected objects dedicated to the general public can provide reliable data in the conditions tested, not even for a qualitative evaluation. For formaldehyde monitoring, we obtained some promising results with a portable device dedicated to professional users. In this paper, we illustrate, with a real test case in an office building, how this device was used for a comparative analysis.
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Nasriddinov A, Rumyantseva M, Shatalova T, Tokarev S, Yaltseva P, Fedorova O, Khmelevsky N, Gaskov A. Organic-Inorganic Hybrid Materials for Room Temperature Light-Activated Sub-ppm NO Detection. NANOMATERIALS (BASEL, SWITZERLAND) 2019; 10:E70. [PMID: 31905665 PMCID: PMC7023258 DOI: 10.3390/nano10010070] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Revised: 12/16/2019] [Accepted: 12/24/2019] [Indexed: 11/30/2022]
Abstract
Nitric oxide (NO) is one of the main environmental pollutants and one of the biomarkers noninvasive diagnosis of respiratory diseases. Organic-inorganic hybrids based on heterocyclic Ru (II) complex and nanocrystalline semiconductor oxides SnO2 and In2O3 were studied as sensitive materials for NO detection at room temperature under periodic blue light (λmax = 470 nm) illumination. The semiconductor matrixes were obtained by chemical precipitation with subsequent thermal annealing and characterized by XRD, Raman spectroscopy, and single-point BET methods. The heterocyclic Ru (II) complex was synthesized for the first time and characterized by 1H NMR, 13C NMR, MALDI-TOF mass spectrometry and elemental analysis. The HOMO and LUMO energies of the Ru (II) complex are calculated from cyclic voltammetry data. The thermal stability of hybrids was investigated by thermogravimetric analysis (TGA)-MS analysis. The optical properties of Ru (II) complex, nanocrystalline oxides and hybrids were studied by UV-Vis spectroscopy in transmission and diffuse reflectance modes. DRIFT spectroscopy was performed to investigate the interaction between NO and the surface of the synthesized materials. Sensor measurements demonstrate that hybrid materials are able to detect NO at room temperature in the concentration range of 0.25-4.0 ppm with the detection limit of 69-88 ppb.
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Affiliation(s)
- Abulkosim Nasriddinov
- Chemistry Department, Moscow State University, Moscow 119991, Russia; (A.N.); (T.S.); (S.T.); (P.Y.); (O.F.); (A.G.)
- Faculty of Materials Science, Moscow State University, Moscow 119991, Russia
| | - Marina Rumyantseva
- Chemistry Department, Moscow State University, Moscow 119991, Russia; (A.N.); (T.S.); (S.T.); (P.Y.); (O.F.); (A.G.)
| | - Tatyana Shatalova
- Chemistry Department, Moscow State University, Moscow 119991, Russia; (A.N.); (T.S.); (S.T.); (P.Y.); (O.F.); (A.G.)
| | - Sergey Tokarev
- Chemistry Department, Moscow State University, Moscow 119991, Russia; (A.N.); (T.S.); (S.T.); (P.Y.); (O.F.); (A.G.)
- A.N. Nesmeyanov Institute of Organoelement Compounds RAS, Moscow 119991, Russia
| | - Polina Yaltseva
- Chemistry Department, Moscow State University, Moscow 119991, Russia; (A.N.); (T.S.); (S.T.); (P.Y.); (O.F.); (A.G.)
| | - Olga Fedorova
- Chemistry Department, Moscow State University, Moscow 119991, Russia; (A.N.); (T.S.); (S.T.); (P.Y.); (O.F.); (A.G.)
- A.N. Nesmeyanov Institute of Organoelement Compounds RAS, Moscow 119991, Russia
| | - Nikolay Khmelevsky
- LISM, Moscow State Technological University Stankin, Moscow 127055, Russia;
| | - Alexander Gaskov
- Chemistry Department, Moscow State University, Moscow 119991, Russia; (A.N.); (T.S.); (S.T.); (P.Y.); (O.F.); (A.G.)
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