Ultrathin PANI-Decorated, Highly Purified and Well Dispersed Array Cncs for Highly Sensitive HCHO Sensors

Abstract

The flocculation of small surficial groups on pristine CNCs (carbon nanocoils) bundles limit their application. In this study, we designed and fabricated novel array CNCs with a surficial decoration of polyaniline (PANI) using in situ methods. Atomic layer deposition (ALD) and chemical vapor deposition (CVD) methods were employed to fabricate the highly pure array CNCs. The array CNCs decorated with ultra-thin PANI were confirmed by different characterizations. Furthermore, this material displayed a good performance in its detection of formaldehyde. The detection results showed that the CNCs coated with PANI had a low limit of detection of HCHO, as low as 500 ppb, and the sensor also showed good selectivity for other interfering gases, as well as good repeatability over many tests. Furthermore, after increasing the PANI loading on the surface of the CNCs, their detection performance exhibited a typical volcanic curve, and the value of the enthalpy was extracted by using the temperature-varying micro-gravimetric method during the process of detection of the formaldehyde molecules on the CNCs. The use of array CNCs with surficial decoration offers a novel method for the application of CNCs and could be extended to other applications, such as catalysts and energy conversion.

Atomic layer deposition to heterostructures for application in gas sensors

“…The morphology of the heterostructures may have an influence on the sensor properties. It has been reported that the confined space within hollow SnO 2 nanocoils after functionalization of ALD NiO enhances the gas adsorption on the surface and improves the sensing performance [30,53]. In air, oxygen chemisorbs onto the surface of MOS materials to form surface oxygen species (O 2 − , O − and O 2− ) [54,55].…”

“…Moreover, ALD is also very effective in depositing metal catalysts, which can be uniformly loaded onto various sensor materials and improve the gas sensing performance [26]. Due to these unique characteristics, ALD is capable of not only synthesizing novel sensor materials, but also manufacturing gas sensor devices with high reproducibility and uniformity [27][28][29][30]. Materials deposited by ALD on a MOS host can be noble metals or MO, either as nanoparticles anchored on the MOS surface or as a conformal coating layer over the MOS structures.…”

Mesoporous-Structure MOF-14-Based QCM p-Xylene Gas Sensor

“…The preparation of the QCM sensor refers to the previous work of our research group [37][38][39], replaced with MOF-14 samples. Testing of the QCM sensor included three steps: (1) baseline obtained by purging with high-purity synthetic air; the gas to be tested was introduced only after the baseline was stable (when the frequency drift does not exceed 5 Hz).…”