THE TIO2/CUO HETEROSTRUCTURE-BASED SENSORS FOR VOLATILE ORGANIC COMPOUNDS (VOCS) AT ROOM TEMPERATURE (RT) MEASUREMENTS

Abstract

For the purpose of evaluating air quality and keeping track of the release of dangerous substances into the environment, the detection of volatile organic compounds (VOCs) is crucial. For this purpose, a number of approaches have been developed, but the majority of them are either high-temperature operations or sophisticated equipment. Therefore, there is a lot of interest in the creation of inexpensive, portable sensors that are capable of detecting VOCs at room temperature. Metal oxide-based sensors have recently received much interest due to their sensitivity and selectivity towards different VOCs. TiO2/CuO heterostructures have shown promise in this regard as materials for VOC sensing applications. TiO2/CuO heterostructures have distinctive electrical characteristics and are readily fabricated using straightforward chemical processes. These heterostructures have been demonstrated to improve the sensitivity, selectivity, and response time of metal oxide-based sensors in order to improve their ability to detect a variety of VOCs. In this study, using a scalable reactive magnetron sputtering technique at glancing angle deposition, we built an ultrasensitive gas-sensing device functioning at room temperature (RT). CuO/TiO2 heterojunction nanointerfaces showed toluene, acetone, and ethanol gas sensitivity for approximately two times greater than TiO2 mono-layer, and the device exhibits an excellent detection limit of 50 ppb at 25°C, short response, and recovery time (40 s and 52 s). The control over nanoarchitecture and similar size of the nanorod-like structure to the doubled Debye lengths (about 70–80 nm) are used to create the ultrasensitivity. The array of p-n heterojunction nanorods was exploited effectively and with minimal technical complexity in the applicable nanoarchitecture design, providing a flexible platform for various gas sensing devices. The statistical study of variances demonstrates that the data gathered is reliable and repeatable.