Hydrothermally Synthesized ZnSnO₃ Nanoflakes Based Low-Cost Sensing Device for High Performance CO₂ Monitoring

Abstract

We report a room-temperature operative ZnSnO3 nanoflakes-based CO2 gas sensor. The perovskite ZnSnO3 nanoflakes are synthesized by one-pot hydrothermal technique. The prepared material characterized via X-ray diffraction (XRD), scanning electron microscopy, UV-visible spectroscopy, and dynamic light scattering measurement to confirm the crystal structure, surface morphology, and optical properties. The XRD pattern revealed that ZnSnO3 was in orthorhombic phase and average crystallite size examined by Scherrer formula was 8.05 nm. Optical studies were done by UV-Vis spectroscopy and the direct optical band-gap was found as 3.27 eV. The surface morphology of the ZnSnO3 was found to be nanoflakes of almost uniform dimensions. The fabricated sensor device of ZnSnO3 detected the CO2 gas at room temperature for different concentrations. The best sensor response was found as 4.93 for 1000 ppm of CO2 whereas at 200 ppm the response and recovery times were found to be 5.92 and 7.23 s, respectively. HOMO-LUMO gap energy of ZnSnO3 without and with interaction from CO2 molecule was found to be 1.165 and 1.577 eV, respectively. Density functional theory studies are used for a better understanding of sensing mechanism.

Development of Yttrium-Cerium Oxide Gas Sensor for Low ppm Hydrogen Detection

“…Both response and recovery time for the YCeO-based sensors are protracted with the increase in H 2 concentration. The recovery time is the amount of time needed to lessen the gap between the maximum and lowest current, and the response time (tres) is the amount of time required for the relative current change to reach 90% of the steady state value following H 2 injection [13][14][15][16]. As shown in Figure 2c,d, the YCeO sensor demonstrated a decent response at 28…”

MoO3/V2CTx Nanocomposite-Based Wearable Sensor with High Sensitivity for Acetone and Hand Sanitizer Detection at Room Temperature with DFT Analysis

“…For performing these computational calculations, we utilized the LanL2DZ basis set and the B3LYP functional. 66 Here, we focused on the HOMO and LUMO energy levels from the DFT study so that we could analyze additional electronic features of these species.…”

“…The optimization was performed with the Gaussian 09 program, and the molecular structures were designed with the Gauss View 05 program. For performing these computational calculations, we utilized the LanL2DZ basis set and the B3LYP functional . Here, we focused on the HOMO and LUMO energy levels from the DFT study so that we could analyze additional electronic features of these species.…”

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“…2 Similarly, it has been reported that 1000 ppm is the threshold limit for the level of CO 2 in occupied buildings. 3 Concentrations above this limit could lead to adverse effects on residents such as fatigue, respiratory inflammation, and headache. 4 CO 2 gas is also relevant in other real-world applications ranging from food packaging to improve perishable food product shelf life (modified atmosphere packaging) to environmental monitoring of greenhouse gases, fire detection, medical diagnostics, and photosynthesis.…”

“…The increase in this atmospheric CO 2 gas level above 400 ppm may have a negative impact on the environment . Similarly, it has been reported that 1000 ppm is the threshold limit for the level of CO 2 in occupied buildings . Concentrations above this limit could lead to adverse effects on residents such as fatigue, respiratory inflammation, and headache .…”