Evaluating the performance of camphor sulfonic acid doped polyaniline-WO3 binary nanocomposite as photocatalyst for degradation of methylene blue dye under solar irradiation

Photocataytic degradation of organic dyes as toxic pollutants are one of the crucial issues in the environmental fields. Conductive conjugated polymers with inorganic semiconductors have been used extensively as photocatalyst due to their high absorption coefficients, high mobility of charge carriers, and good environmental stability [1, 2]. In this research, camphor sulfonic acid doped polyaniline-WO3 (CSA doped PANI-WO3) nanocomposite was synthesized via in situ emulsion polymerization and used as photocatalyst for degradation of methylene blue (MB) under solar irradiation. The synthesized nanocomposite was characterized with Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, Field emission scanning electron microscopy (FESEM) and Energy dispersive X-ray spectroscopy (EDS). In order to photocatalytic studies, 50 mg of pure WO3 and CSA doped PANI-WO3 were dispersed in 50 mL aqueous solution containing 10 ppm of MB. The suspensions were stirred in dark conditions for 30 min to establish an adsorption-desorption equilibrium. Then the suspensions were irradiated with 250 W Xenon lamp. At given intervals, samples were taken and centrifuged at 4000 rpm for 15 min. The supernatants were analyzed with T80+ UV/VIS spectrophotometer (PG. Instruments Ltd). The degradation percentage of MB was obtained 43 % and 85 % for pure WO3 and CSA doped PANI-WO3, respectively. Also, the constant rate of CSA doped PANI- WO3 is 7.49 times higher than pure WO3. It is concluded that MB could be degraded more efficiently in the presence of CSA doped PANI- WO3 nanocomposite.