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

Abstract

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 CO 2 sensor utilizing NBA−ZnO nanohybrids shows outstanding sensing performance with a maximum response of ∼9% to 500 ppm of CO 2 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 CO 2 sensing application.

Stable and sensitive amino-functionalized graphene/polyaniline nanofiber composites for room-temperature carbon dioxide sensing

“…This further increases the resistance of the AmG/PANI sensor in the presence of CO 2 . 25,41 Thus, the enhanced CO 2 sensing properties of the AmG/PANI nanober sensor can be attributed to the presence of the primary amine functional group and the p-n junction between p-type PANI and n-type AmG.…”

“…24-26 CO 2 is a hard acid and can efficiently interact with the amino groups, which are hard bases, to form carbamates or bicarbonates, resulting in an increase in resistance. 24,25 In this work, we used ethylenediamine [NH 2 -(CH 2 ) 2 -NH 2 ] to functionalize the graphene surfaces, similar to in our previous work. 27 Many studies have demonstrated that primary amine groups are highly efficient in adsorbing CO 2 gas.…”

“…27 Many studies have demonstrated that primary amine groups are highly efficient in adsorbing CO 2 gas. [23][24][25] Therefore, in this work, the fundamental mechanism of CO 2 sensing is the efficient binding of amino-functionalized graphene with CO 2 at room temperature (RT) to form carbamates via a reversible reaction. Polyaniline (PANI) has been widely studied for gas detection based on its high sensitivity, fast response time, and functionality at room temperature.…”

Functionalized Reduced Graphene Oxide Thin Films for Ultrahigh CO2 Gas Sensing Performance at Room Temperature

“…Novel materials, such as amino-ZnO [ 13 ], Ru@WS 2 [ 14 ], vanadium oxide [ 15 ], nanodiamonds [ 16 ], Al/maPsi/n-Si/Al [ 17 ], and carbon nanotube [ 18 ], have been recently explored for CO 2 gas sensing at room temperature. However, the sensing thin films of these materials require a mild thermal treatment before the sensing at room temperature.…”

Investigation of the structural, optical and gas sensing properties of PANI coated Cu–ZnS microsphere composite

“…CO 2 sensors are widely used in many applications such as air-quality monitoring, food packaging, greenhouse-gas monitoring, medical diagnosis, re detection, and consumer electronics. [1][2][3] Another crucial requirement for monitoring the level of CO 2 is found inside the greenhouse, where the growth of plants is directly dependent on the CO 2 concentration. Therefore, regulation and monitoring of the CO 2 level is also important in the agriculture industry.…”