Enhanced Gas-Sensing Properties for Trimethylamine at Low Temperature Based on MoO₃/Bi₂Mo₃O₁₂ Hollow Microspheres

Abstract

Most reported trimethylamine (TMA) sensors have to operate at high temperature, which will consume energy highly. To detect TMA at low temperature, it is necessary to modify the existing materials or develop new materials. In this paper, the sensor based on MoO 3 /Bi 2 Mo 3 O 12 hollow microspheres can work at low operating temperature of 170 °C, which were prepared via a simple solvothermal route. The phase and morphology of the product were characterized by an X-ray diffraction meter, a scanning electron microscope and a transmission electron microscope. The surface chemistry of the MoO 3 /Bi 2 Mo 3 O 12 sensor was studied with an X-ray photoelectron spectroscope to investigate the TMA sensing mechanism. The MoO 3 /Bi 2 Mo 3 O 12 sensor (S = 25.8) had a higher response to 50 ppm TMA than those of MoO 3 hollow spheres (S = 10.8) and Bi 2 Mo 3 O 12 sensors (S = 4.8) at 170 °C. In contrast to the pure MoO 3 and Bi 2 Mo 3 O 12 sensors, the MoO 3 /Bi 2 Mo 3 O 12 sensor exhibited an obviously enhanced gas-sensing property for TMA, which might be due to the heterostructure formed between MoO 3 and Bi 2 Mo 3 O 12 and the hollow morphology. It is the first time for MoO 3 /Bi 2 Mo 3 O 12 to apply in gas sensors, which might take an important step in the application of MoO 3 /Bi 2 Mo 3 O 12 or Bi 2 Mo 3 O 12 in the field of gas sensing. KEYWORDS: MoO 3 /Bi 2 Mo 3 O 12 hollow microspheres, heterostructure, low temperature, TMA sensing property, gas-sensing mechanism

Room-temperature ppb-level trimethylamine gas sensors functionalized with citric acid-doped polyvinyl acetate nanofibrous mats

“…1,2 The maximum allowable exposure duration to TMA is as low as 15 min with a concentration of o15 ppm. 3 Otherwise, it becomes hazardous to humans, which can then cause several health problems (i.e., headache, breathing difficulty, pulmonary edema, nausea, and irritation of the upper respiratory system). 3,4 Other than its direct inhalation possibility from the environment, TMA may also affect human health through unsafe foods, as it can be released from decayed meat and seafood products (i.e., foods that are no longer fresh).…”

Advances in the designs and mechanisms of MoO3 nanostructures for gas sensors: a holistic review

“…In particular, these 3-D HNS owing to their large SSA and minimized interparticle agglomerations, provides an easier gas molecule diffusion and faster charge propagation on the material's surface, thus resulting in high sensitivity and a faster response sensing speed 10,169 . Till now, a variety of 3-D MoO3 nanostructures, including nano/micro-flower 83,84,[166][167][168]170 , hierarchical 53,73,[130][131][132][133][134][135] , nanoarrays [177][178][179] , hollows spheres 180,181 , core-shell [182][183][184] , microcage 185 , nanopompon 186 , and microbox 187 have been designed and used in the gas sensing applications (Table 3).…”

“…The reason for the improved sensing performance could be due to the Au NPs, which on coordinating with the aromatic rings of xylene, dissociate them faster as compared to the other test gases. Using a similar ST strategy, Zhang and coworkers 181 first time reported the MoO3/Bi2Mo3O12 hollow microspheres for detecting the TMA gas. The SEM and TEM image in Figure 20e displayed the presence of a hollow microsphere (diameter ~1.2 μm) whose surface was found to be smooth with some pores observed on it.…”

A Gas Sensor With Fe2O3 Nanospheres Based on Trimethylamine Detection for the Rapid Assessment of Spoilage Degree in Fish

“…The assessment of fish freshness using a gas sensor based on a metal oxide semiconductor material that detects TMA represents a non-destructive and rapid detection method, and has been studied widely. This method has the advantages of high sensitivity, low cost, convenient and rapid detection process, and has played an important role in rapid and non-destructive detection of fish freshness ( Chen et al, 2014 ; Chang et al, 2017 ; Wang et al, 2018 ; Zhang et al, 2019 ). Nano-α-Fe 2 O 3 is a typical n-type semiconducting metal oxide with a forbidden band width of 2.2 eV.…”