α-Fe2O3/NiO heterojunction nanorods with enhanced gas sensing performance for acetone

The rod-like alpha-Fe2O3/NiO heterojunction nanocomposite was prepared by one-step hydrothermal method. These nanorods were composed of numerous NiO and alpha-Fe2O3 nanoparticles. The p-n heterojunction between NiO and alpha-Fe2O3 built the heterojunction barrier at the interface of the two oxides. The amount of oxygen vacancies and the adsorbed oxygens of alpha-Fe2O3/NiO composite were increased because of the existence of the heterojunction, which enhanced the gas sensing properties. The response of alpha-Fe2O3/NiO sensor reached 290 for 100 ppm acetone at the optimum work temperature of 280 degrees C. Besides, it exhibited the fast response/recovery time (28 s/40 s), good selectivity and long-term stability. Therefore, this work provides a facile approach to prepare alpha-Fe2O3/NiO heterojunction nanocomposite as a promising material of gas sensors for detecting acetone.