Sonochemical preparation and characterization of Sm‐doped GO/KSrPO4 nanocomposite photocatalyst for degradation of methylene blue dye

The present work pertains to synthesis of Sm‐doped GO/KSrPO4 (GO/KSrPO4:Sm) nanocomposite using ultrasound‐assisted method. Successful decoration of graphene oxide sheets with the KSrPO4:Sm3+ phosphor was confirmed using analysis techniques including SEM, EDS, UV/visible spectrometry, XRD, and FTIR of the prepared GO/KSrPO4:Sm nanocomposite. Further, photocatalytic activity of this nanocomposite material was studied by examining degradation of methylene blue (MB) dye from water. The effects of several parameters like concentration of Sm3+ in KSrPO4:Sm3+ phosphor within the GO/KSrPO4:Sm nanocomposite photocatalyst, photocatalyst loading, initial dye concentration, pH, and preparation method were evaluated. At a higher concentration of Sm3+ in the photocatalyst (1 mol.%), higher photocatalyst loading (1.5 mg/ml), lesser dye concentration (20 mg/L), and higher pH (11.4), the GO/KSrPO4:Sm nanocomposite photocatalyst prepared using ultrasound‐assisted method showed higher dye removal compared to other conditions. A maximum of 83.35% removal of MB dye was achieved by the use of ultrasonically prepared GO/KSrPO4:Sm nanocomposite photocatalyst having a concentration of 1 mol.% of Sm3+ in the KSrPO4:Sm3+ phosphor at a loading of 1.5 mg/ml, initial dye concentration of 20 mg/L, and a pH of 11.4. Rate constant for MB dye degradation using the GO/KSrPO4:Sm nanocomposite photocatalyst synthesized by ultrasonic‐assisted method was found to be 0.0053 min−1. Practitioner Points GO/KSrPO4:Sm nanocomposite photocatalyst prepared by ultrasonic‐assisted method. Higher Sm3+ doping in nanocomposite with the use of ultrasound assisted method showed better performance of photocatalyst. A maximum removal of 83.35% of methylene blue dye was achieved. The Sm‐doped GO‐KSrPO4 nanocomposite synthesized using ultrasound‐assisted method is able to efficiently photodegrade methylene blue dye mainly at a higher Sm3+ concentration, photocatalyst loading, and pH and a lower initial dye concentration.