Dual-selectivity and high-sensitivity sensor for dibutylamine and diisopropylamine detection using ZnO nanoparticles with tetragonal dipyramidal morphology

The simultaneous detection of the toxic gases Dibutylamine (DBA) and Diisopropylamine (DIPA) by ZnO has not been reported, making dual detection of these gases a challenge. In this paper, a tetragonal dipyramid-like ZnO precursor was prepared using a hydrothermal method, focusing on microstructural changes at different calcination temperatures and their effects on gas sensing performance. After calcination at 550 °C, tetragonal dipyramid-like ZnO (ZnO_TD-550) was obtained, featuring two grooves that serve as “bridges” between the two tetragonal cones. The structure consists of uniform nanoparticles with a broad mesoporous distribution, high specific surface area, and abundant oxygen vacancies. These features collectively enable rapid gas reactions, enhancing sensor sensititity. The tetragonal dipyramid-like ZnO sensor exhibits an significant response to 100 ppm DBA at 133 °C (S = 300.6), and a comparable response to the same concentration of DIPA at 217 °C (S = 271.5). The ZnO_TD-550 sensor also demonstrates a low detection limit, excellent long-term stability, reproducibility and humidity resistance for DBA/DIPA detection. This pioneering study reveals the capability of ZnO-based sensors for highly sensitivity and dual-selectivity detection of the toxic gases DBA and DIPA at distinct operating temperatures. In addition, the dual-sensitivity mechanisms have been thoroughly explored and analyzed.