An acetone gas sensor based on nanosized Pt-loaded Fe2O3 nanocubes

Nanosized Pt-loaded Fe2O3 nanocubes are prepared through, successively, a simple hydrothermal reaction, two-step annealing process and finally reduction with NaBH4 of H2PtCl4. The resultant Pt decorated Fe2O3 nanocubes, made up of Fe2O3 nanoplatelets, are hierarchical, hollow and porous, with an average edge length of 200–300 nm. The sensor based on Pt decorated Fe2O3 nanocomposites exhibits higher response (Rair/Rgas = 25.7) to 100 ppm of acetone gas at lower temperature (139 °C), with a short response-recovery time (3 s/22 s), compared with pure Fe2O3 nanocubes sensor. The Pt-Fe2O3 nanocomposite sensor shows excellent potential to act as a low cost, low temperature sensor for acetone gas, with high acetone selectivity under high humidity conditions and with the interference of other gases. Under various environmental conditions designed to mimic exhaled air, the sensor is able to detect ppb amounts of acetone, with high repeatability and stability, making it suitable for applications such as oral diabetic sensors. The attractive chemical and electronic sensitizations of partially oxidized Pt nanoparticles are responsible for the enhancement of acetone sensing performance. Based on the high acetone selectivity, high stability and fast dynamic response, the Pt enhanced Fe2O3 nanocubes sensor is an exceptionally suitable candidate for a low cost acetone sensor, and the proposed approach provides a route to develop gas sensors that can operate at low temperatures for a wide variety of applications.