π‑Conjugated Amine–ZnO Nanohybrids for the Selective Detection of CO₂ Gas at Room Temperature

The development of a new type of hybrid material comprising naphthalene-based π-conjugated amine (NBA) and zinc oxide (ZnO) nanohybrid, grown in situ on polydimethylsiloxane (PDMS) flexible substrate, is explored. The morphology of the nanohybrids is controlled by optimizing growth time of the hydrothermal reaction. The CO₂ sensor utilizing NBA–ZnO nanohybrids shows outstanding sensing performance with a maximum response of ∼9% to 500 ppm of CO₂ at room temperature and a comparatively fast response/recovery time (∼3/6 min). The sensor has excellent mechanical flexibility with consistent sensing performance under bending/relaxing process. Hydrophobic nature of the NBA provides less humidity effect on the sensing performance of the NBA–ZnO nanohybrids, which make it suitable for room-temperature application. Also, the presence of layer-by-layer assembly in the NBA–ZnO nanohybrids provides a superior path for carrier transport, which reduces the response and recovery time. All these results indicate that NBA–ZnO nanohybrid is a promising material for room temperature CO₂ sensing application.