Mohammed Faiad NaiefSamar Naser MohammedYasser Naji AhmedAhmed Mishaal Mohammed2025-02-112023NAIEF, Mohammed Faiad, et al. Synthesis and characterisation of MWCNTCOOH and investigation of its potential as gas sensor. Inorganic Chemistry Communications, 2023, 157: 111338.‏https://doi.org/10.1016/j.inoche.2023.111338https://ds.uofallujah.edu.iq/handle/123456789/398The synthesis of MWCNT-COOH involves functionalizing multi-walled carbon nanotubes (MWCNTs) with carboxyl groups (-COOH) through oxidation, typically using nitric acid. This enhances their chemical reactivity and dispersibility. Characterization techniques like TEM, SEM, FTIR, and XPS confirm the structure and functionalization of the nanotubes. MWCNT-COOH are investigated as gas sensors due to their high surface area and electrical conductivity. The carboxyl groups interact with gases, causing changes in the nanotubes' electrical properties, which can be measured to detect gases. They offer high sensitivity, selectivity, and potential applications in environmental monitoring, industrial safety, and medical diagnosticsMonitoring and control of hazardous gases have been a top concern because they lead to serious public health issues, such cardiovascular diseases, respiratory illnesses, central nervous system abnormalities and other ill nesses. These gases are also linked to global warming, which affects the surrounding environment. Therefore, harmful emissions should be limited and neutralised. Traditional gas sensors have slow speed, expensive oper ation, labour and capital intensive and invasive. Scholars need to develop an inexpensive, rapid, efficient, highly sensitive, portable sensors with a low power consumption and a high level of reliability. In this study, multi- walled carbon nanotubes (MWCNTs) were synthesised using plant byproducts. TEM, FE-SEM and AFM were employed to identify MWCNTs. Gas test showed that the sensor had high sensitivity levels of 5.6 and 8.8 and response times as low as 24.3 and 21.6 s for H2 S and NO 2 , respectively.enArticle