Synthesis and Characterization of CeO2/Ag3PO4 p-n Heterojunction Photocatalyst: Its Photocatalytic Activity for the Degradation of Alizarin Yellow Dye
Tigabu Bekele
Abstract
Novel single and binary photocatalysts were synthesized by coprecipitation method. The crystal structure, surface area, morphology, bandgap energy, functional groups, and optical properties were characterized using XRD, BET, SEM-EDX, UV/vis, FTIR, and PL instruments, respectively. Aqueous solutions of the model contaminant alizarin yellow (AY) dye and real wastewater sample solutions were used to evaluate the photocatalytic activity of single and binary nanocomposite. We found that the photocatalytic activity of CeO2/Ag3PO4 binary nanocomposite is higher than that of their individual counterparts. We investigated the effects of operating parameters such as pH, initial dye concentration, and photocatalytic loading on AY dye degradation. Under optimal conditions, the binary system showed an efficiency of 96.99%. The binary photocatalyst showed relatively higher AY photolysis efficiencies than actual wastewater, about 96.56% and 57.76%, respectively. The actions of various scavengers suggest that ·O2 and ·OH scavengers play an important role in AY decomposition. When the reusability of the photocatalyst was tested, only a reduction of about 20% was observed after four consecutive runs. The degradation of AY follows pseudo-first-order kinetics for newly synthesized nanocomposite. This result indicates that the binary nanocomposite can serve as an excellent medium for electron transport.