Constructing of Bi2O3-In2O3 nanofibers for sensitive detection of freshness gas markers in aquatic products

Abstract

In order to quickly and accurately detect and then evaluate the freshness of fish, trimethylamine is used as a landmark gas for detection. In this study, an alternative trimethylamine chemosensor based on Bi₂O₃-In₂O₃ nanofibers (NFs) was synthesized successfully through the electrospinning method. The structure, morphology and chemical states of Bi₂O₃-In₂O₃ NFs were characterized. The results of gas sensing tests indicated that after doping In₂O₃ with 3 % Bi₂O₃, the sensor displays better sensitivity to trimethylamine (48.6–100 ppm), which was 2.9 times higher than pure In₂O₃ (NTs) gas sensor (16.4) at the optimal operating temperature of 250 °C. Under low concentrations of trimethylamine (0.5 ppm), the 3 % Bi₂O₃-In₂O₃ NFs sensor still has a specific sensitivity (1.3). The increased sensitivity of 3 % Bi₂O₃-In₂O₃ NFs sensor is attributed to the increase of oxygen vacancy, which can be confirmed by XPS and UV-vis methods. The sensor sensitivity decreased as the relative humidity increased, but the response remained at approximately 10 even under a high humidity environment of 90 %. The excellent performances towards trimethylamine indicate that 3 % Bi₂O₃-In₂O₃ NFs are prospective candidates for trimethylamine gas sensor fabrication.