Chemical Sensing Properties of BaF₂-Modified <i>h</i>BN Flakes towards Detection of Volatile Organic Compounds

• Main Authors: Boitumelo J. Matsoso, Clara Garcia-Martinez, Thomas H. Mongwe, Bérangère Toury, José P. M. Serbena, Catherine Journet
• Format: Article
• Language: English
• Published: MDPI AG 2021-09-01
• Series: Chemosensors
• Subjects: <i>h</i>BN; acetone; ethanol; chemoresistive sensing; sensitivity; BaF₂-modification
• Online Access: https://www.mdpi.com/2227-9040/9/9/263

The application of BaF₂-modified <i>h</i>BN flakes as rapid response and recovery as well as sensitive chemoresistive sensing device materials for detection of acetone and/or ethanol is presented in this study. Modification of the <i>h</i>BN flakes was achieved by using the modified polymer derived ceramics (PDCs) process through the use of 0–10 wt% BaF₂ and 5 wt% Li₃N. Upon exposure to individual acetone and ethanol vapours, room temperature sensing studies revealed high LoD values (−144–460 ppm_acetone and −134–543 ppm_ethanol) with extremely compromised sensitivities of −0.042–0.72 × 10⁻² ppm⁻¹_acetone and −0.045–0.19 × 10⁻² ppm⁻¹_ethanol for the structurally improved 5–10 wt% BaF₂-modified <i>h</i>BN flakes. Moreover, enhanced sensing for 0–2.5 wt% BaF₂-modified <i>h</i>BN flakes, as shown by the low LoDs (−43–86 ppm_acetone and −30–62 ppm_ethanol) and the high sensitivities (−1.8–2.1 × 10⁻² ppm⁻¹_acetone and −1.5–1.6 × 10⁻² ppm⁻¹_ethanol), was attributed to the presence of defects subsequently providing an abundance of adsorption sites. Overall, the study demonstrated the importance of structural properties of <i>h</i>BN flakes on their surface chemistry towards room temperature selective and sensitive detection of VOCs.