Room-temperature CO detection using facile CTAB - assisted Mo - doped Co3O4 nanoflowers

Abstract

The elevated concentration of carbon monoxide (CO) originating from diverse anthropogenic and natural sources poses a significant risk to human health and the environment, contributing to global warming and the onset of severe health disorders. While metal oxide-based sensors are widely studied, most require high temperatures or have poor sensitivity at room-temperature (RT) (25⁰C). In this work, cetyltrimethylammonium bromide-assisted molybdenum-doped cobalt oxide (CTAB-assisted Mo-doped Co3O4) nanostructures have been synthesized via the facile hydrothermal technique. Furthermore, various material characterizations such as X-Ray diffraction (XRD), Field emission scanning electron microscope (FESEM), Brunauer-Emmett-Teller (BET), and UV-Vis spectroscopy were employed to investigate the crystallinity, structural morphology, active surface area and bandgap, respectively. The incorporation of CTAB and molybdenum doping has enhanced the gas sensing performance at RT (25⁰C). The CTAB-assisted Co3O4 doped with 2.5 mol% Mo demonstrated an exceptional response of 4188% toward 100 ppm CO at RT (25⁰C). In addition, the fabricated sensor shows a limit of detection (LoD) and limit of quantification (LoQ) of 4 and 12 ppb, respectively. Thus, the fabricated CTAB-assisted 2.5 mol% Mo-doped Co3O4 sensor shows an excellent response with rapid response and recovery times of 42 and 54 s, respectively, at RT (25⁰C). Copyright © 2026. Published by Elsevier B.V.