Chemical Gas Sensors Studied at SENSOR Lab, Brescia (Italy): From Conventional to Energy-Efficient and Biocompatible Composite Structures

Abstract

In this paper, we present the investigations on metal oxide-based gas sensors considering the works performed at SENSOR lab, University of Brescia (Italy). We reported the developments in synthesis techniques for the preparation of doped and functionalized low-dimensional metal oxide materials. Furthermore, we discussed our achievements in the fabrication of heterostructures with unique functional features. In particular, we focused on the strategies to improve the sensing performance of metal oxides at relatively low operating temperatures. We presented our studies on surface photoactivation of sensing structures considering the application of biocompatible materials in the architecture of the functional devices as well.

A computational study of a chemical gas sensor utilizing Pd–rGO composite on SnO2 thin film for the detection of NOx

“…They fabricated sensor using the 2 mm × 2 mm × 0.254 mm alumina substrate and platinum as a lead. The electrical characteristics of transition metal oxides are changed due to the adsorption/desorption processes of gases analytes on their surface of the electrode 1 . Chemical gas sensors are hugely used in fields such as environmental pollutant monitoring, industrial safety measures, and universal security.…”

Solution-processed In2Se3 nanosheets for ultrasensitive and highly selective NO2 gas sensors

“…A detailed description of the configuration of the chemoresistive sensing device and gas test system was reported in our previous works. 78,79…”

“…A detailed description of the conguration of the chemoresistive sensing device and gas test system was reported in our previous works. 78,79 In 2 Se 3 layers were dispersed in isopropanol at a concentration of 3 mg mL −1 . The prepared dispersion was drop cast on the surface of Al 2 O 3 substrates.…”

Al2O3/ZnO Heterostructure-Based Sensors for Volatile Organic Compounds in Safety Applications

“…Volatile organic compounds (VOCs), which originate from multiple sources such as household items, cooking appliances, paint, oil refineries, and vehicle exhaust emissions, are highly hazardous vapors that significantly affect human health and air quality in various industrial environments. − Despite having been investigated extensively over the past few years, the sensing properties toward VOCs need to be improved continuously to meet the most up-to-date requirements for specific applications and to withstand the harsh industrial environments, especially when using heterostructures or heterojunctions of two or more metal oxides. − The selective detection of low concentrations of VOCs is highly important to underpin the continuous monitoring of human health and for environmental safety . Among the various types of materials available, the semiconducting–metal oxide-based chemo-resistive sensors are considered to be promising candidates for the detection of VOCs, , especially those comprising heterostructures/heterojunctions containing two or more different oxides, as these materials show excellent potential for their application in portable solid-state devices because of their low cost, high efficiency, simple preparation method, and good stability. − In the context of real-world applications, the response parameter is influenced by several factors, including the morphology, microstructure, defects, and heterojunctions of the VOC sensors as well as the relative humidity . The response and selectivity performance of solid-state gas sensors can be improved further through control of their properties and, especially, by developing new multilayered or heterostructured oxides with a coating of Al 2 O 3 nanofilms.…”