Boosted natural sunlight driven photodegradation of organic dyes using rGO anchored Pr/Cu dual-doped ZnO nanocomposite: Characterization and mechanistic insight

Abstract

The advancement of sunlight-driven metal oxide semiconductor-based, highly efficient photocatalysts for removing contaminants like dyes from wastewater remained a challenge. In this work, Pr/Cu dual-doped ZnO anchored with different rGO concentrations were synthesized by simple co-precipitation and ultrasonication route. The structural, morphological, and optical characterization of prepared materials was performed with different techniques and employed for degrading diverse kinds of dyes pollutants under natural sunlight illumination. The photodegradation efficiency after 40 min sunlight illumination towards Methyl Orange (MO) was 51.00, 75.00, and 99.76% for ZnPrCuO (S1), ZnPrCuO/rGO (1:1) (S2), and ZnPrCuO/rGO (1:2) (S3), respectively. The results suggested that the introduction of Pr/Cu and rGO significantly boosted the photodegradation ability of ZnO under sunlight. Especially, S3 nanocomposite exhibited the highest photodegradation of safranin-O (SO), Rhodamine-B (RhB), and methylene blue (MB) dyes, having degradation efficiency of 65.50, 91.40, and 99.80%, respectively, in 40 min. The scavenger test results exhibited that •OH and •O2− were the foremost active species in the photodegradation process. Moreover, the reusability experiments and tracing XRD after reusing samples revealed that the S1 catalyst has excellent recyclability (6th cycle). The reduction in energy bandgap and creation of impurity energy level by Pr/Cu doping leads to inhibit carrier pair recombination and effective charge transfer/separation. These findings revealed that Pr/Cu doping and rGO have the potential to enhance the visible light response of ZnO to eliminate dyes pollutants in wastewater with energy saving.