Preparation of cobalt phosphate/silver phosphate via microwave irradiation for photodegradation of Rhodamine B / Nur Nadiah Hanim Idris

Large amounts of water pollution are caused by the textile industry's usage of synthetic colors. Textile dyes do not bind tightly to the fabric and are discharged as effluent into the aquatic environment. Thus, the continual discharge of wastewater from a great variety of textile companies without prior treatment has serious detrimental effects on environmental quality and human health. Photocatalytic degradation is an effective destructive method to remove the dye wastewater. In this study, the synthesis of Co3(PO4)2 with Ag3PO4 (CP/AP) was applied as a photocatalyst via microwave irradiation method to degrade Rhodamine B dye. The results of the prepared CP/AP were characterized using several instruments, including field emission scanning electron microscopy (FESEM), Fourier transform infrared (FTIR), and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis/DRS). The photocatalytic activity of the catalyst was observed in the degradation of Rhodamine B for 60 minutes using a 0.375 g/L catalyst. 5 CP/AP shows the highest rate (96%) >10 CP/AP (92%)> Ag3PO4 (87%) > 1 CP/AP (82%) > 15 CP/AP (73%) > Co3(PO4)2 (71%). The enhancement of the 5 CP/AP was due to the well distribution of Co and P elements on Ag3PO4 and narrowest band gap. Then, CP/AP was carried out for other parameters such as initial pH, catalyst dosage and concentration of RhB. The result shows the highest performance at pH 9, concentration of RhB at 10 mg/L and catalyst dosage at 0.375 g/L. Meanwhile, the scavenger study confirmed that photogenerated holes (h+) plays a crucial role in photodegradation of RhB. Overall, the Co3(PO4)2 on Ag3PO4 was successfully contribute on photoreduction of RhB under visible light.