Polyaniline supported CdS/CeO2/Ag3PO4 nanocomposite: An "A-B" type tandem n-n heterojunctions with enhanced photocatalytic activity

In the present work, ternary composites of the form CdS/CeO2/Ag3PO4 with CdS:CeO2/Ag3PO4 molar ratios of (1:1, 2:1, 3:1 and 4:1) were synthesized by co-precipitation method. Polyaniline supported CdS/CeO2/Ag3PO4 nanocomposite was also synthesized by "in situ" chemical oxidative method. Physicochemical properties of the photocatalyst materials were determined using XRD, BET, SEM-EDX, TEM, UV/Vis, FTIR and PL techniques. Photocatalytic activities of the ternary CdS/CeO2/Ag3PO4 (1:1, 2:1, 3:1 and 4:1 molar ratios) nanocomposites were found to be higher than their single and binary counterparts. The effects of different operational parameters such as pH, initial dye concentration, photocatalyst load and scavengers in MeO dye degradation study confirmed the following optimum values: pH 4, initial dye concentration 10 ppm and photocatalyst load 0.15 g/L. The effects of different scavengers suggest that center dot O-2- and center dot OH scavengers play major roles in the degradation of MeO. The supported photocatalyst exhibited a relatively higher efficiency (93.4%) on the photodegradation of MeO dye. In addition, it showed fairly well photocatalytic activity (70.7%), for the textile effluent collected from one of the local textile industries. Furthermore, the reusability of the supported photocatalyst was tested. About 80% of the catalyst efficiency was maintained after four successive runs exhibiting the potential application of this novel composite for degradation of MO dye from aquatics system.