Effect of inorganic anions on the photocatalytic decolorisation of an azo dye in the aqueous phase by cadmium sulphide/polymer nanocomposite films under visible light irradiation

Batch experiments were carried out to study the effects of various inorganic anions on the photocatalytic decolorisation of an azo dye (CI Methyl Orange 13025) in the aqueous phase in the presence of cadmium sulphide/polymer nanocomposite films under visible light irradiation. When anion concentrations were low (0.001 m), the inhibition effect on the photocatalytic decolorisation of CI Methyl Orange 13025 caused by these anions was ranked as . The presence of both and baffled the breakage of the benzene ring in the chemical structure of CI Methyl Orange 13025, while the presence of was of benefit to the degradation of the benzene ring. Adsorption experiments indicated that inorganic anions affected the decolorisation of CI Methyl Orange 13025 by competitive adsorption onto the surface of the photocatalyst. The photocatalytic decolorisation of CI Methyl Orange 13025 followed the pseudo‐first‐order kinetic reaction model well in all experimental cases.