CTAB assisted growth and characterization of nanocrystalline CuO films by ultrasonic spray pyrolysis technique

• Published in: Applied surface science 2011-09, Vol.257 (22), p.9546-9554
• Main Authors: Singh, Iqbal, Kaur, Gursharan, Bedi, R.K.
• Format: Article
• Language: English
• Subjects: ACTIVATION ENERGY; AMMONIA; Cationic surfactants; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; COPPER OXIDE; Cross-disciplinary physics: materials science; rheology; CRYSTAL STRUCTURE; Crystallites; CUPRIC OXIDE; DEPOSITION; Exact sciences and technology; Physics; Planes; Precursors; Sensor; Spray pyrolysis; SPRAYING; Surface chemistry; SURFACTANTS; ULTRASONICS
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2011.06.061

[Display omitted] ► Effect of CTAB on the structural and morphological properties of CuO films. ► CTAB assisted CuO films show an increase in activation energy of conduction. ► CTAB doped CuO films show good sensitivity for NH 3 at room temperature. ► Two adsorption models used for exploring the kinetics of sensing mechanism. An aqueous solution of cupric nitrate trihydrate (Cu(NO 3) 2·3H 2O) modified with cetyltrimetylammonium bromide (CTAB) is used to deposit CuO films on glass substrate by chemical spray pyrolysis technique. The thermal analysis shows that the dried CTAB doped precursor decomposes by an exothermic reaction and suggests that minimum substrate temperature for film deposition should be greater than 270 °C. X-ray diffraction (XRD) studies indicate the formation of monoclinic CuO with preferential orientation along (0 0 2) plane for all film samples. The CTAB used as cationic surfactant in precursor results in the suppression of grain growth in films along the (1 1 0), (0 2 0) and (2 2 0) crystal planes of CuO. Surfactant modified films showed an increase in crystallite size of 14 nm at substrate temperature of 300 °C. The scanning electron micrographs (FESEM) confirm the uniform distribution of facets like grains on the entire area of substrate. CTAB modified films show a significant reduction in the particle agglomeration. Electrical studies of the CuO films deposited at substrate temperature of 300 °C with and without surfactant reveal that the CTAB doping increase the activation energy of conduction by 0.217 eV and room temperature response to ammonia by 9%. The kinetics of the ammonia gas adsorption on the film surface follows the Elovich and Diffusion models.