Semiconductor Metal Oxides as Chemoresistive Sensors for Detecting Volatile Organic Compounds

Abstract

Volatile organic compounds (VOCs), which originate from painting, oil refining and vehicle exhaust emissions, are hazardous gases that have significant effects on air quality and human health. The detection of VOCs is of special importance to environmental safety. Among the various detection methods, chemoresistive semiconductor metal oxide gas sensors are considered to be the most promising technique due to their easy production, low cost and good portability. Sensitivity is an important parameter of gas sensors and is greatly affected by the microstructure, defects, catalyst, heterojunction and humidity. By adjusting the aforementioned factors, the sensitivity of gas sensors can be improved further. In this review, attention will be focused on how to improve the sensitivity of chemoresistive gas sensors towards certain common VOCs with respect to the five factors mentioned above.

Graphene derivative coated QCM-based gas sensor for volatile organic compound (VOC) detection at room temperature

“…Thus, this defective nature of carbon structure is primarily accountable for the adsorption of the VOC gas molecules. Such defects are favorable for VOC gas sensing [29]. The second-order D-peak (i.e.…”

CO2 and O2 Detection by Electric Field Sensors

“…The detection and the measurement of gas concentrations can be carried out using several principles. The most common working principles, sensors, and systems used for gas detection are: electrochemical sensors [1,2], systems based on Quartz Crystal Microbalances [3], sensors based on semiconductors [4,5], optical sensors [6], capacitive sensors [7], cantilever-based sensors [8], and colorimetric devices [9].…”

“…It is ambitious to propose a gas sensor which is completely novel (especially for the detection of oxygen and carbon dioxide) with sensitivity, resolution, selectivity, and repeatability better than the ones given by the existing technologies (reported in References [1][2][3][4][5][6][7][8][9][10]). All the mentioned sensors (not pretending to be exhaustive) are complementary in terms of pros and cons, and the best solution can be selected among them for each different application.…”

A Langasite Crystal Microbalance Coated with Graphene Oxide-Platinum Nanocomposite as a Volatile Organic Compound Sensor: Detection and Discrimination Characteristics

“…Hence, it is of paramount importance to be able to sense these VOC molecules when present in the environment. The sensing of VOCs plays a critical role in various fields such as medical diagnostics, food quality control, environmental surveillance, and explosives detection [1,2]. It is simply insufficient to be able to sense the VOC molecules; it is even more significant to distinguish the VOC molecule types as they have similar physical and chemical properties.…”

“…In general, a VOC sensor comprises an active sensing material and a transducer device to output the sensing signal that reflects the interactions between the sensing material and the gas molecules. Commercial VOC sensors available currently are predominantly based on metal oxide sensing layer which necessitates a heating element to operate [1]. This limits the uses of the metal oxide-based sensors to static scenarios and are, therefore, inappropriate for modern applications such as wearables where portability, low power consumption, and ambient temperature sensing are essential [7].…”