Semiconductor Metal Oxides For Hydrogen Gas Sensing

The only practical way to imitate human nose function is via gas sensors which monitor air quality and provide a mean to premature alert of potential risk. A gas sensor can form a part of an early warning system, notifying the appropriate authorities or provide the feedback signal to a process control system. To achieve this, the gas sensor must be accurate and stable in-situ real time measurements. It is foreseen that hydrogen energy will form the infrastructure that will power future societies since it is a clean, cost-effective and renewable source of energy. However, hydrogen, being flammable gas, has a lower expolsion limit of 4% in air meaning that even a small spark can ignite the mixture. Therefore, hydrogen generation, transport and storage can be dangerous if not handled with caution. This requires high precision sensitive gas sensors which are able to detect the smallest leaks fastly. Semiconductor Metal Oxide gas sensors are an important candidate for this task.

The second edition of this book focuses on the synthesis, design, and application of semiconducting metal oxides as gas sensing materials, including the gas sensing mechanism, and modification methods for sensing materials, while also providing a comprehensive introduction to semiconductor gas sensing devices. As an essential part of IoT (Internet of things), gas sensors have shown great significance and promising prospects. Therefore, studies on functional mesoporous metal oxides, one of the most important gas sensing materials based on their unique Knudsen diffusion behavior and tailored pore structure, have increasingly attracted attention from various disciplines. The book offers a valuable reference guide to metal oxide gas sensing materials for undergraduate and graduate students alike. It will also benefit all researchers who are involved in synthesis and gas sensing of metal oxides nanomaterials with relevant frontier theories and concepts. Engineers working on research and development of semiconductor gas sensors will also find some new ideas for sensor design.

Semiconductor Gas Sensors, Second Edition, summarizes recent research on basic principles, new materials and emerging technologies in this essential field. Chapters cover the foundation of the underlying principles and sensing mechanisms of gas sensors, include expanded content on gas sensing characteristics, such as response, sensitivity and cross-sensitivity, present an overview of the nanomaterials utilized for gas sensing, and review the latest applications for semiconductor gas sensors, including environmental monitoring, indoor monitoring, medical applications, CMOS integration and chemical warfare agents. This second edition has been completely updated, thus ensuring it reflects current literature and the latest materials systems and applications. Includes an overview of key applications, with new chapters on indoor monitoring and medical applications Reviews developments in gas sensors and sensing methods, including an expanded section on gas sensor theory Discusses the use of nanomaterials in gas sensing, with new chapters on single-layer graphene sensors, graphene oxide sensors, printed sensors, and much more

Gas Sensors Based on Conducting Metal Oxides: Basic Understanding, Technology and Applications focuses on two distinct types of gas sensors based on conducting metal oxides. Ion conduction, applied in so-called solid-state electrolytic sensors for one, and electronic conduction used in semiconductivity gas sensors for the other. The well-known ?–probe, a key component to optimize combustion in car engines, is an example of the former type, and the in-cabin car air-quality control SnO2 and WO2 sensor array stands for the semiconductivity type. Chapters cover basic aspects of functioning principles and describe the technologies and challenges of present and future sensors. Provides reader background and context on sensors, principles, fabrication and applications Includes chapters on specific technological applications, such as exhaust sensors, environmental sensors, explosive gases alarms and more Presents a structured presentation that allows for quick reference of vital information

The first chapter of the book summarizes classical approaches, introduces the concept of ionicity, and describes the mixed iono-covalent character of the oxygen cation bond in bulk materials. The next three chapters focus on the characteristics of the atomic structure (relaxation, rumpling and reconstruction effects), the electronic structure (band width, gap width, etc.) and the excitations of clean surfaces.

Metal Oxide Nanostructures as Gas Sensing Devices explores the development of an integrated micro gas sensor that is based on advanced metal oxide nanostructures and is compatible with modern semiconductor fabrication technology. This sensor can then be used to create a compact, low-power, handheld device for analyzing air ambience.The book first c

The Stannic Oxide Gas Sensor presents a comprehensive overview of the background science and technology of the subject, including practical information on its applications and the electronic circuits with which it is associated. The book explains the chemistry of the device and covers typical methods of fabrication. Sensitivity and selectivity are addressed, and the problems of drift with ambient temperature, relative humidity, and time are fully discussed. The book also presents examples of industrial, commercial, and domestic applications. It explains the design of appropriate electronic circuits and describes methods for testing and characterizing sensors. Advantages and disadvantages of sensors are assessed as well.

Provides an introduction to the topic of smart chemical sensors, along with an overview of the state of the art based on potential applications This book presents a comprehensive overview of chemical sensors, ranging from the choice of material to sensor validation, modeling, simulation, and manufacturing. It discusses the process of data collection by intelligent techniques such as deep learning, multivariate analysis, and others. It also incorporates different types of smart chemical sensors and discusses each under a common set of sub-sections so that readers can fully understand the advantages and disadvantages of the relevant transducers—depending on the design, transduction mode, and final applications. Smart Sensors for Environmental and Medical Applications covers all major aspects of the field of smart chemical sensors, including working principle and related theory, sensor materials, classification of respective transducer type, relevant fabrication processes, methods for data analysis, and suitable applications. Chapters address field effect transistors technologies for biological and chemical sensors, mammalian cell–based electrochemical sensors for label-free monitoring of analytes, electronic tongues, chemical sensors based on metal oxides, metal oxide (MOX) gas sensor electronic interfaces, and more. Addressing the limitations and challenges in obtaining state-of-the-art smart biochemical sensors, this book: Balances the fundamentals of sensor design, fabrication, characterization, and analysis with advanced methods Categorizes sensors into sub-types and describes their working, focusing on prominent applications Describes instrumentation and IoT networking methods of chemical transducers that can be used for inexpensive, accurate detection in commercialized smart chemical sensors Covers monitoring of food spoilage using polydiacetylene- and liposome-based sensors; smart and intelligent E-nose for sensitive and selective chemical sensing applications; odor sensing system; and microwave chemical sensors Smart Sensors for Environmental and Medical Applications is an important book for senior-level undergraduate and graduate students learning about this high-performance technology and its many applications. It will also inform practitioners and researchers involved in the creation and use of smart sensors.

Gas sensor technology has advanced remarkably during past few decades and has become one of the indispensable technologies for modern society. Varieties of gas sensors are commercially available and, using innovative ideas, efforts are being made to develop gas sensors of next generation having very small size with very low power consumption. The ultimate model for this is probably given by sensory organs of our own body, which are implanted finely and work well with a very modest amount of energy. In order to achieve this goal, it is essential that various aspects of gas sensors are seriously considered. These include understanding of gas sensing mechanisms, development of new materials and methods to synthesise them into selective sensors, innovations in nanostructured materials, measurement methods, microfabrication of sensors, exploring intelligent sensing system, etc. This book examines these issues pertaining to chemiresistive gas sensors.

An overview of the principles & current technology of the main sensor types used for flammable gas detection, oxygen monitoring in combustion & car-exhaust control. Also includes toxic gas monitoring. A companion volume to Techniques & Mechanisms in Gas Sensing.