Selective dual detection of hydrogen sulfide and methyl mercaptan using CuO/CuFe2O4 nanopattern chemiresistors

• Published in: Sensors and actuators. B, Chemical Chemical, 2021-12, Vol.348, p.130665, Article 130665
• Main Authors: Lim, Kyeorei, Jo, Young-Moo, Kim, Seonghwan, Yoon, Ji-Wook, Jeong, Seong-Yong, Kim, Jun-Sik, Choi, Hun Ji, Cho, Youngkyu, Park, Jangpyo, Jeong, Yong Won, Lee, Jong-Heun
• Format: Article
• Language: English
• Subjects: Air monitoring; Air quality; Copper; Copper oxides; Dual-mode gas sensor; Hydrogen sulfide; Indoor air pollution; Indoor air quality; Malodor gas sensor; Nanofibers; Nanoparticles; Near-field electrospinning; Oxide nanopattern; Sensors; Sulfur compounds; Volatile sulfur compound sensor
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2021.130665

Volatile sulfur compounds (VSCs), such as H2S and methyl mercaptan (MM), are malodorous and harmful gases. H2S and MM share analogical origins. However, they should be discriminated because of their different odor thresholds and health impacts. Herein, a nanopattern chemiresistor composed of aligned CuO-loaded CuFe2O4 nanofibers was prepared via direct-write near-field electrospinning. The CuO/CuFe2O4 sensor with the atomic ratio of [Cu]:[Fe] = 3:4 exhibited extremely high responses to ppm-level H2S and MM compared with other nanopattern sensors with different compositions ([Cu]/[Fe] = 2:4, 4:4, and 0:1). This can be attributed to the gas-accessible morphology of the nanopattern sensor, the formation of a nanoscale p(CuO)-n(CuFe2O4) junction, and the intimate reaction between the discretely loaded CuO nanoparticles and the VSCs. Furthermore, the CuO/CuFe2O4 sensor exhibited high selectivities to H2S and MM at 200 ℃ and 400 ℃, respectively. The selective dual detection of H2S and MM using a single CuO/CuFe2O4 sensor via the simple modulation of the sensing temperature opens a new route for indoor air quality monitoring, ventilation control, halitosis diagnosis, and wine quality monitoring. [Display omitted] Nanopattern sensor using 1D CuO/CuFe2O4 nanofibers fabricated by direct-writing near-field electrospinning exhibits high selectivity and response to volatile sulfuric compounds and the modulation of sensing temperature enables the discrimination between H2S and methyl mercaptan. •CuO/CuFe2O4 nanopattern sensor was fabricated using near-field electrospinning.•Sensor temperature modulation enabled selective dual detection of H2S and methyl mercaptan.•PCA using the array of four Cu-Fe-O nanofiber sensors enabled the discrimination between volatile sulfuric compounds and interference gases.•Mechanism underlying gas selectivity control was elucidated by proton transfer reaction quadruple mass spectrometry.