MoO₃ Nanorods Decorated by PbMoO₄ Nanoparticles for Enhanced Trimethylamine Sensing Performances at Low Working Temperature

Abstract

The gas sensing performance of metal oxides is limited by the lack of conductivity and sensing activity. Inducing the release of more electrons and activating more chemisorbed oxygen ions to participate in the gas sensing reaction can effectively overcome this limitation. The development of a PbMoO 4 /MoO 3 heterostructure prepared by the addition of Pb 2+ ions with MoO 3 nanorods is reported for highly sensitive and selective trimethylamine (TMA) detection. The response of the PbMoO 4 /MoO 3 sensor (33.2) to 10 ppm TMA is improved 3-fold compared to the MoO 3 sensor (10.7), and the working temperature is reduced from 170 to 133 °C. The enhanced gas sensing performance and mechanism of PbMoO 4 /MoO 3 were demonstrated using the energy band diagram and X-ray photoelectron spectroscopy (XPS) analysis. It is mainly attributed to the following promotion: (1) the induction of Pb 2+ ions increases the electron density around the Mo element, enabling the decorated MoO 3 to release electrons easily; (2) the formed PbMoO 4 /MoO 3 heterojunction endows a high degree of electron transfer at the interface; (3) the formation of the potential barrier causes the device resistance to decrease significantly upon TMA exposure. Finally, the practicability of the sensor was verified by detecting TMA released from Carassius auratus and shrimp to reflect their freshness.

Functionalized Multiwalled Carbon Nanotubes for Highly Stable Room Temperature and Humidity-Tolerant Triethylamine Sensing

“…These results indicate that surface-absorbed oxygen contributes to the TEA-sensing reaction, which is consistent with previous literature. 6 To verify eq 9, we performed GC-MS characterization to detect the gaseous components. Figure S6a shows the results of the gaseous products generated during the interaction of TEA with the sensing material and adsorbed oxygen.…”

“…15 Furthermore, selectivity is improved to some extent by introducing metal−organic-framework (MOF) sieving effects; these reports still limit the ppm-level detection of TEA at higher temperatures. 6,14 Therefore, it is valuable to develop new VOC or volatile amine-sensing materials for infield applications, such as room-temperature operation with part-per-billion (ppb) level detection, portability, fast reversible response, excellent selectivity, and consistent performance over time.…”

Nanoporous Graphene Oxide-Based Quartz Crystal Microbalance Gas Sensor with Dual-Signal Responses for Trimethylamine Detection

“…To date, various gas sensors for TMA detection have been developed with good sensing performance, including resistance sensors [8][9][10], colorimetric sensors [11][12][13][14], biosensors [15,16], kinetics methods [17] and spectral imaging [18][19][20]. However, these sensors generally have certain deficiencies, such as high operating temperature, poor stability and insufficient detection limit of TMA below its odor threshold [5,21].…”

Ultrasensitive Flexible Olfactory Receptor-Derived Peptide Sensor for Trimethylamine Detection by the Bending Connection Method

“…Various sensing structures and materials have been employed for gas sensors. , For example, nanospheres, nanorods, thin films, and three-dimensional (3D) flowers formed by metal oxides, polymers, and graphene have been used to detect distinct gaseous substances. − However, the selectivity and limit of detection (LOD) of these sensing materials are yet to be improved. In recent years, the olfactory receptor-derived peptide (ORP), derived from the odorant-binding sites of olfactory receptors, has emerged as a new gas-sensing material .…”

“…Graphite and metal oxide materials, e.g., graphene-NiGa 2 O 4 , WS 2 /MWCNTs, PbMoO 4 , TiO 2 -NiFe 2 O 4 , Rh/ZnO, and NiO-In 2 O 3 , have traditionally been used to produce gas sensors for the detection of TMA. However, these gas sensors using these materials have a sensitivity to TMA at only part per million to part per billion (ppm–ppb) levels, and they also have unsatisfactory selectivity. ,− …”