The design of praseodymium galena nanospheres: An effective photocatalyst for the remediation of carcinogenic phenothiazine and chromium contaminants

Abstract

Herein, we report the synthesis of nanosphere-shaped praseodymium lead sulfide nanoparticles (PrPbS NPs) using a simple environmentally benign sonochemical technique, which have been well characterized using various spectroscopic and microscopic techniques. The nanosphere shaped PrPbS NPs were applied as a dual role photocatalyst for the degradation of hazardous methylene blue (MB) dye and the conversion of carcinogenic hexavalent chromium (Cr6+) to trivalent chromium (Cr3+) under visible light irradiation. The effective experimental parameters, such as the catalyst dosage (30 mg in 100 mL), initial concentration (30 mg/L and 20 mg/L), and pH influence (pH 7.0 and pH 3.0) of the environmental pollutant were studied. In addition, the effect of scavenging particles for the degradation of MB and Cr6+ were analyzed with help of various scavenging particles. The mechanisms for the photodegradation of MB and conversion of Cr6+ were predicted using radical scavenger measurements. Moreover, degradation efficiencies toward MB and hexavalent Cr6+ of 99.2 and 96.6%, respectively were achieved in the presence of the PrPbS NPs. These results reveal the PrPbS nanospheres are synthesized by an ecofriendly procedure and applied as photocatalyst for the effective degradation of MB and Cr6+.