Synthesis and NH ₃ /TMA sensing properties of CuFe ₂ O ₄ hollow microspheres at low working temperature

Abstract

Abstract In this work, CuFe 2 O 4 hollow microspheres assembled with nanosheets (CuFe 2 O 4 HMANs) were synthesized using a solvothermal method followed by an annealing treatment. The effects of annealing temperature on microstructure, chemical composition and gas sensing characteristics of as‐prepared samples were investigated. The results showed that annealing treatment played a crucial role in the final products. All samples demonstrated hollow spherical morphology assembled with nanosheets or nanoparticles. The CuFe 2 O 4 HMANs annealed at 400 °C exhibited the best n‐type conductometric sensing properties toward low‐concentration NH 3 at 100 °C and 49%RH. The sensor response to 10 × 10 −6 NH 3 was 4.0 with a rapid response time of 32 s, and it even showed a response of 1.2 toward 1 × 10 −6 NH 3 at the same condition, while a response of 3.95 to trimethylamine (TMA). The CuFe 2 O 4 HMANs‐based NH 3 sensor also exhibited good selectivity and excellent reproducibility. Therefore, this work provided a novel promised sensing material of low‐concentration NH 3 and TMA for real‐time monitoring.