Enhanced photocatalytic performance and reusability of N-doped carbon dots/zinc oxide hybrid nanostructures

Abstract

We report the fabrication of nitrogen-doped carbon dots-zinc oxide hybrid (NCDs-ZnO) nanostructures utilizing simple chemical procedures. The role of NCDs in ZnO nanostructured matrix has been analyzed through XRD, SEM, FTIR and PL characterization techniques. The introduction of NCDs was found to modify not only their aspect ratio, observed by a reduction in the preferred c-axis growth compared to the a- and b-axis, but also induced an additional emission around 441 nm, which is typical of NCDs. The hybrid nanostructures were utilized as catalyst for methylene blue dye degradation showing a 95% degradation after 2 h of UV irradiation in comparison to the ∼70% degradation obtained by utilizing pristine ZnO, while the dye half-life (t 1/2) was reduced by ∼65% by utilizing NCDs-ZnO hybrid nanostructures when compared to the pristine ZnO. The reusability of the fabricated hybrid structures was tested up to eight times with no significant loss in their photocatalytic performance (>90%). The stability of the hybrid structures was verified through Z-potential measurements prior and after reutilization. Excellent reusability and simple processing presented by NCDs-ZnO hybrid nanostructures makes them promising for industrial level photocatalyst for the waste water treatment.