Journal of Materials NanoScience <p>Journal of Materials NanoScience is a peer reviewed indexed international journal for publication of research advances in Materials Science, Advanced Materials, Chemistry of Materials, Polymers, NanoScience, Nanotechnology, Biomaterials, Bionanotechnology and smart materials development.</p> en-US (Editorial, J Material NanoScience) (Tech Support ScienceIn) Sun, 06 Mar 2022 00:00:00 +0000 OJS 60 Recent advances in Materials development and design for Gas Sensing applications <p>The detection of specific gases in different settings have emerged as an essential requirement towards management of different sectors such as industries, agriculture, laboratories, supply chains etc. The development of sensors using different materials play pivotal role in application of gas sensors in real time conditions. Many different type of materials have been studied, utilized and applied for the development of gas sensors. The compilation of research advances in the field of new gas sensors would provide better understanding towards applications of advanced functional materials. The current compilation encompasses recent trends in the area of nanostructured gas sensors. Various aspects of developing a gas sensor such as materials synthesis, characterization and optimization of sensor parameters, gas sensing methodologies, mechanistic studies, theoretical modeling and real-life applications are discussed. The research advances in form of concise reviews and original research articles in different gas sensing areas have been covered. The current research direction in developing novel materials, various technologies adopted to advance the sensing capabilities in order to realize an end user preferred device is elucidated. This effort is aimed at providing various avenues to a researcher where research can be focused in order to develop a gas sensor.</p> Arun K Prasad, Sridharan Madanagurusamy Copyright (c) 2022 ScienceIn Publishing Tue, 15 Feb 2022 00:00:00 +0000 Gas sensing of partially oxidized Ti3C2Tx MXene in argon atmosphere <p>Multilayer accordion like Ti<sub>3</sub>C<sub>2</sub>T<em><sub>x</sub></em> MXene is prepared by selective etching of Al layer from Ti<sub>3</sub>AlC<sub>2</sub> MAX phase.&nbsp; For better gas sensing responses, a minimal amount of TiO<sub>2</sub> decoration is being carried out by annealing the Ti<sub>3</sub>C<sub>2</sub>T<em><sub>x</sub></em> MXene in an argon atmosphere at 550 °C for 6 h. The X-ray diffraction pattern shows successful removal of Al layer and TiO<sub>2</sub> decoration on Ti<sub>3</sub>C<sub>2</sub>T<em><sub>x</sub></em> MXene surface which is well supported by field emission scanning electron microscope images. Due to TiO<sub>2</sub> decoration, MXene shows semiconducting behaviour and corresponding bandgap is 3.2 eV. Resistance of TiO<sub>2</sub> decorated MXene sample increases in presence of H<sub>2</sub>, CH<sub>4</sub> and NO<sub>2</sub> gases at room temperature. However, resistance of the sample decreases for H<sub>2</sub>, and CH<sub>4</sub> gases and increases for NO<sub>2</sub> gas at 100 °C which shows n-type semiconducting behaviour. Also, at 100 °C, sensitivity increases by one order to that of room temperature gas response of TiO<sub>2</sub> decorated MXene sample. &nbsp;</p> Nasima Khatun , Sanju Rani, Govinda Behera, Somnath Roy Copyright (c) 2022 ScienceIn Publishing Tue, 15 Feb 2022 00:00:00 +0000 Detection of Geraniol in Palmarosa Essential oil using Silicone Sealant as molecularly imprinted polymer in a QCM sensor <p>Geraniol is a commercially significant terpene alcohol found in the essential oils of a variety of aromatic plants. It is one of the most important molecules in the flavor and fragrance industries, and a common ingredient in consumer products. In order to detect geraniol in real samples, silicone sealant, a readily available commercial product, was used as the polymer to prepare a molecularly imprinted polymer (MIP) based quartz crystal microbalance (QCM) sensor and is presented in this paper. Optimum ratio of sealant was dissolved in dichloromethane and then geraniol was added as the template molecule to synthesize the coating material of the sensor. The surface of the QCM with silver electrode was modified using the synthesized MIP solution by the drop coating method. The developed sensor showed reasonably good sensitivity and selectivity to geraniol and was employed to detect the concentration of geraniol at ppm level in different palmarosa essential oil samples. Good correlation was obtained with the responses from gas chromatography.</p> Swatilekha Roy, Shreya Nag, Mahuya Bhattacharyya Banerjee, Samhita Dasgupta, Panchanan Pramanik, Rajib Bandyopadhyay Copyright (c) 2022 ScienceIn Publishing Tue, 15 Feb 2022 00:00:00 +0000 Methane sensing studies of ex-situ oxidized sputtered V2O5 nanostructured films: Effect of post oxidation duration <p>The effect of microstructural modifications of V<sub>2</sub>O<sub>5</sub> thin films, obtained through alterations in post oxidation duration, on methane sensing behavior is reported for the first time. Three different oxidation times viz., 1 h, 3 h and 5 h yielded varied microstructure and vibrational properties as evident from XRD and Raman investigation. These changes in properties manifest as differences in gas sensing behavior. Methane sensing properties of V<sub>2</sub>O<sub>5</sub> was investigated in temperature range from 100 to 300 °C and optimum operating temperature of 200 °C was identified for all three samples. Films oxidized for 1 h showed the highest response due to favorable surface conditions which are discussed. These results will help in tailoring microstructure towards device level application processes.&nbsp;</p> Gomathi Natarajan, Reshma P. R, Ashok Bahuguna, Ramanathaswamy Pandian, Arun K Prasad Copyright (c) 2022 ScienceIn Publishing Tue, 08 Feb 2022 00:00:00 +0000 Electronic Nose based on chemiresistive sensors for toxic gas detection <p>Development of gas sensors satisfying the ‘4-S sensor selection criterion’ is a daunting challenge. This criterion demands the accomplishment of performance satisfying the parameters namely sensitivity (sensor response), selectivity, stability and suitability. For chemiresistive sensors to achieve an optimum sensor configuration, optimization of parameters namely, sensing material, its thickness, amount and distribution, deposition method, pre and post deposition treatment, operating temperature and involved sensing mechanism is pre-requisite and a humongous task. Use of multiple sensors each having partial specificity towards a target gas is looked upon as a means to achieve a configuration satisfying the 4-S criterion. Besides, it offers advantages of cross verification and/or validation, removal of false or faulty sensor, overall reliability and simultaneous detection of multiple gases. These systems are often classified as an electronic nose or e-nose. Their important function is to mimic the mammalian olfactory system. However, its usage involves the complexity of data acquisition and analysis employing advanced date analytics such as machine learning and artificial neural networks. The present article reviews and summarizes the activity on electronic nose especially for toxic gas detection. Care has been taken to include some of the recent findings crucial for realizing a complete working and portable e-nose.</p> Niranjan S. Ramgir, K. R. Sinju, Bhagyashri Bhangare, A. K. Debnath Copyright (c) 2022 ScienceIn Publishing Tue, 15 Feb 2022 00:00:00 +0000 Enhanced room temperature selective ammonia sensing based on SnO2 decorated MXene <p>SnO<sub>2</sub>/MXene nanocomposites were prepared by decorating SnO<sub>2</sub> nanoparticles over few layer MXene using ultra-sonication. &nbsp;The SnO<sub>2</sub>/MXene composite exhibit highly selective and sensitive towards trace level ammonia detection at room temperature. The linear sensing response R<sup>2</sup>=0.938 and R<sup>2</sup>=0.971 obtained for ammonia concentration 0.5 to 5 ppm and 10 to 100 ppm respectively.&nbsp; The SnO<sub>2</sub> nanoparticles loaded MXene sheets shows shorter response time about 16 sec compared with pristine SnO<sub>2</sub> response time (~61 sec). The formation of Schottky junction between SnO2 and MXene results in the formation the charge depletion between the SnO2/MXene interface and further the charge depletion increases over ammonia vapor interaction resulting in the increase of the sensor resistance. Besides, quick reversibility over 50 cycles, room temperature operation, high sensitivity, faster response/recovery time, and simple fabrication approach of making SnO<sub>2</sub> loaded MXene materials could be interesting for making next generation selective detection of ammonia molecules.&nbsp;&nbsp;</p> Kamaraj Govindharaj, MathanKumar Manoharan, Krishnamoorthy Rajavel, Yuvaraj Haldorai, Rajendrakumar R T Copyright (c) 2022 ScienceIn Publishing Tue, 15 Feb 2022 00:00:00 +0000 Recent progress in Nanostructured Metal Oxides based NO2 gas sensing in India <p>The metal oxides are considered as an outstanding semiconductor material to sense several toxicants from the environment. In particular, the nanostructure containing rod, wire, and tube-like morphology of metal oxides were widely utilized to fabricate effective gas sensors worldwide. Out of number of toxicant, nitrogen dioxide (NO<sub>2</sub>) is one of the highly reactive gas, results from the burning of fuel from vehicles, power plants, and off-road equipment.The exposures to NO<sub>2</sub>&nbsp;may giverise to the development of the respiratory diseases and leads to the death. Therefore, the efficient detection of NO<sub>2</sub> gas is the urgent need of recent era. More than 5000 research articles were published on the NO<sub>2</sub> gas sensing worldwide. The researchers from India is also contributed a lot to detect the NO<sub>2</sub> gas via nanostructured metal oxides powder and thin films. The aim of the present article is to explore the recent advances of NO<sub>2</sub>&nbsp;gas sensors based on metal oxide nanomaterials within the country. The review begins with the general introduction of metal oxide, gas sensorand NO<sub>2</sub> gas sensor and followed by the broadly discussion of major research groups working in India and their finding in the fieldof nanostructured metal oxide for the fabrication of NO<sub>2</sub>&nbsp;gas sensors. Moreover, various factors likegas concentrations, working temperature, morphologies, sensor response, selectivity, etc. of metal oxides were discussed in the present report. The report concludes with the future directions and opportunities in the field of detection of NO<sub>2</sub> gas in India and world.</p> Sharadrao Vanalakar, V. L. Patil, S. M. Patil, S. B. Dhavale, T. D. Dongale, P.S. Patil Copyright (c) 2022 ScienceIn Publishing Tue, 15 Feb 2022 00:00:00 +0000 A comprehensive review on functionalized Hydroxyapatite nanostructures based gas sensors for environmental pollutant monitoring <p>The utilization of advanced sensing techniques for detecting and monitoring toxic gases in industry and the environment is a predominant action. For such applications, the sensor material should possess higher sensitivity, faster detection, and real-time operation. Mostly, metal oxides (MOs) are preferred for gas sensing purposes owing to their excellent sensing property, wide band-gap, electrical conductivity, and high surface reactivity. But, the same MOs lag in many perspectives like low selectivity, higher operating temperature (&gt; 400 °C), more power consumption, and reduced stability. Since more emphasis is given to materials that operate at room temperatures like nano-hydroxyapatite (nHAp), it’s a bio-ceramic material used for chemical gas sensing. The nHAp is a matrix of rich calcium (Ca<sup>2+</sup>) and phosphate (PO<sub>4</sub><sup>3-</sup>) ions. In chemical gas sensors, the nHAp possess significant properties like large surface phosphate-hydroxide (P-OH) groups, ionic conductivity, porous nature, and ion exchange capability for effective gas molecule interaction. In this profound review, we discussed the nHAp structure with different fabrication techniques for gas sensing. Particularly, functionalized nHAp with MO and polymers were focused and their stability, sensitivity, selectivity, and adsorption rate are presented along with different mechanisms. Existing challenges and future perspectives of nHAp material are also highlighted.</p> N. Manjubaashini, G. Radha, S. Balakumar Copyright (c) 2022 ScienceIn Publishing Tue, 15 Feb 2022 00:00:00 +0000 Defect mediated optical detection of ammonia using SnO2 nanoparticle <p>SnO<sub>2</sub> with oxygen vacancies, an <em>n</em>-type gas sensing material used commercially as resistive sensors at high temperatures, suffers from the drift in voltage, contact resistances and poor selectivity. These prevailed defects in rutile SnO<sub>2</sub> offer excellent optical properties which remain to be explored for the gas sensor. Apart from advantage of contactless operation with no direct voltage application, an optical method with the varied light energies is highly beneficial for excitations of the deep electronic states at ease, with opportunity to improve the sensor response measurement quickly in selective manner. In this direction, we report the synthesis and characterization of SnO<sub>2</sub> nanostructures with emphasis on their Raman and photoluminescence properties. In subsequence, the crucial role of various defects in displaying the improved optical responses and selectivity for ammonia are highlighted. &nbsp;</p> Binaya Kumar Sahu, Gurpreet Kaur, Arindam Das Copyright (c) 2022 ScienceIn Publishing Thu, 27 Jan 2022 00:00:00 +0000 Multiphysics modeling and optimisation of gas flow characteristics in a novel flow metric based gas sensing chamber with integrated heater <p>Gas sensing is a very vital and commonly adapted process in various industries and service sectors. The gas sensing can be as mundane as exhaust gas from an automotive vehicle to as critical as a flammable, hazardous, or even toxic gas in environments where they find a considerable requirement, such as industries or in hospitals. It is crucial to detect the leakage of gases in these environments to maintain the operability of some systems or prevent catastrophic incidents in others. Various gas sensors have been developed to sense these gases present individually or as a mixture with other gases. The reliability of a gas sensor is highly dependent on the gas sensor calibrating or testing chamber. The credibility of the gas sensing chamber would dictate the gas sensors’ performance. A gas sensor needs to be observed or characterized for its characteristic such as sensitivity, selectivity, temperature-dependent response variation, sensing accuracy and precision, repeatability, response towards the exposed gas, response time, etc. These characteristics can be accurately studied only when the gas chamber’s behavioral characteristics are predetermined and well characterized. The paper intends to propose a flow metric-based gas sensing chamber against the conventional volumetric chamber and presents the gas flow nature in the chamber. The chamber is designed with a single inlet port and single exhaust vent or outlet port. The placement of the substrate holder with respect to the chamber dimensions, flow characteristics in the chamber has been optimized to provide a laminar flow over the substrate, resulting in higher sensing ability of the gas sensor. The paper also deals with the boundary layer suppression to provide maximal gas flow over the substrate, thereby enhancing the chance of sensing by the gas sensor. An integrated heater is also provided below the substrate holder, which is required since some gas sensors operate at high temperatures for optimal performance. Study on heat propagation from the heater onto the substrate holder is also involved.&nbsp; The flow characteristics of the entire chamber were analyzed, especially at the inlet port, over the substrate, and at the outlet port. The paper focuses on the complete modeling of the gas sensing chamber, fluid dynamic studies of the gas flow inside the chamber, optimal substrate placement, optimal angling of the substrate facing the gas flow, and the heat propagation from the heater onto the substrate holder.</p> K Govardhan, S Muthuraja, A Nirmala Grace Copyright (c) 2022 ScienceIn Publishing Tue, 15 Feb 2022 00:00:00 +0000