Synthesis and characterisation of neodymium doped-zinc oxide–graphene oxide nanocomposite as a highly efficient photocatalyst for enhanced degradation of indigo carmine in water under simulated solar light

A nanocomposite (Nd–ZnO–GO) with enhanced photocatalytic properties was synthesized by co-precipitation method. The structures, morphologies and photocatalytic activities of the nanocomposite were studied using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and ultraviolet–visible spectroscopy. Indigo carmine (IC) dye was used to evaluate the photocatalytic performance of the nanocomposite under simulated solar light. The photocatalytic results indicate that the nanocomposite [Nd–ZnO–GO (0.3 % Nd)] showed good photocatalytic activity and could be considered as a promising photocatalyst for treatment of organic pollutant in water. The high and efficient photocatalytic degradation of IC solution by the nanocomposite [Nd–ZnO–GO (0.3 % Nd)] is attributed to improve absorbance in the visible region and the separation of charge carriers due the combined effect of Nd and GO. Analysis from Total organic carbon (TOC) displayed a higher degree of complete mineralisation of IC (TOC removal of 76 %) which decreases the formation of possible toxic degradation by-products. The stability of Nd–ZnO–GO (0.3 % Nd) nanocomposite caused it to be reused for five times reaching 83.0 % degradation efficiency after the five cycles.