Porous SnO2-B: doped polypyrrole thin films were synthesized by the dissolving 0.15M of stannous chloride (SnCl4.5H2O) (10%, 20%, 30%, 40%, and 50%) in 25ml of ethanol and adding 4% of Boric acid (H3BO3) and polypyrrole (1:1) using chemical spray pyrolysis technique. Studies on effect of substrate temperature on porosity of the deposited films were at four different temperatures ranging 200⁰C to 280⁰C. The H2S gas was used to study the gas sensing behavior of deposited films and all films were characterized by using IR, XRD, SEM, UV-Vis spectrometry, and current-voltage measurement.

Porous CaMnO3 doped polyaniline nano composite thin films were synthesized by the doping CaMnO3 by weight percentage (5%, 10%, 15%, 20%, and 25%) in aqueous solution of polyanline using chemical polymerization technique. The produced films were characterized by X-ray diffraction (XRD), UV-Visible spectroscopy, Infrared spectroscopy (IR), scanning electron microscope (SEM), d.c electrical conductivity, and dielectric constant measurements. The optical properties of all investigated films were studied, where the optical absorption of the prepared films decreases with increasing the amount of CaMnO3 in both VIS (500–700 nm) and UV (200–400 nm) regions. The increase in conductivity with increase in concentration of CaMnO3 has been observed in CaMnO3 doped polyaniline composites. The H2S gas was used to study the gas sensing behavior of investigated films.