Hydrothermally synthesized spherical g-C3N4-NiCo2O4 nanocomposites for ppb level ethanol detection

Gas-sensing materials that can detect ethanol concentration at ppb level have attracted widespread attention. Unique nanostructures assisted by novel nanocomposites are promising candidates for gas sensor applications. Herein, spherical NiCo2O4 decorated onto the g-C3N4 layered structure has been synthesized via hydrothermal method, which has been devoted actually to detect volatile and hazardous vapors. The structures and physical properties of synthesized nanocomposites were confirmed by various techniques such as XRD, SEM, TEM, HRTEM, SAED, FTIR, Raman, XPS and BET methods. A series of sensors were fabricated from the synthesized composites to detect ethanol vapors to a minimum concentration. Meanwhile, the sensor of 6 wt% g-C3N4NiCo2O4 (NCO-6) obtained an effective response, good selectivity, short response/recovery time, valuable stability and reproducibility to 100 ppm ethanol. Additionally, the limit of detection was 10 ppb ethanol, to which the response of 1.92 was obtained. Compared with the response of 2.1-100 ppm ethanol from NCO-0 sensor, the NCO-6 sensor exhibited a response of 19.2 at the same condition. The improvement of response was discussed in several aspects, such as layered g-C3N4 structures, the increased BET specific surface area and the increase of oxygen species adsorbed on the surface of the composites. The present study proposes the nanocomposites with layered g-C3N4 and spherical NiCo2O4, which are potential gas-sensing materials with promising applicability because of the linear relation between response and ethanol concentration.(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

A nanocomposite with spherical NiCo2O4 decorated onto g-C3N4 layered structure was synthesized for detecting ethanol vapors, showing a low detection limit, enhanced response, and excellent stability and selectivity.