Oxygen vacancies rich in indium oxide hollow prism-like nanoflowers derived from NH₂-MIL-68 (In) for promoted triethylamine sensing

Triethylamine (TEA) is widely viewed as the toxic volatile organic compounds and causes a severe risk to environmental protection and human health. However, the current sensors are still unable to meet the growing demand for effective and reliable detection of TEA gas. Herein, a newly designed TEA sensor based on In₂O₃ prism-like nanoflowers with hollow mesoporous structure is designed by directly calcining NH₂-MIL-68 (In) in air atmosphere. A series of analytical techniques are performed such as BET, XPS, UV–vis, PL, EPR and Hall effect measurements. All the characterization results prove that the In₂O₃-400 prepared by annealing NH₂-MIL-68 at 400 ℃ exhibits the maximum concentration of oxygen vacancies, the highest specific surface area, and excellent electron mobility, resulting in the best performance toward TEA. The prepared In₂O₃-400-based sensors possess ultrahigh response of 684.32 when exposed to 7 ppm TEA at 100 ℃ and exhibit a minimum detection limit of 0.046 ppb. The remarkable performance makes the sensors based on In₂O₃-400 prism-like nanoflowers become a very competitive sensing material for the detection of trace TEA vapor. The excellent selectivity, repeatability and long-term stability ensure the actual application of the prepared sensors.