Room-temperature ammonia sensor based on cationic surfactant-assisted nanocrystalline CuO.

CuO nanocrystalline powder was synthesized by a sol-gel auto combustion route with different amounts of the cetyltrimethylammonium bromide (CTAB) used as cationic surfactant. The samples were characterized by XRD, FESEM, and TEM techniques. The electrical properties of the samples without and with different CTAB concentration and the response to ammonia gas at room temperature have been investigated. The CTAB appears to influence the morphology and the properties of CuO powder. The lattice constant values of the samples indicate monoclinic structure. TEM indicate the crystallite size around 7 nm for the CuO with 0.5M CTAB. The addition of surfactant results in an increase in the response of CuO thick films for ammonia at room temperature.