Ternary reduced graphene oxide–CuO/ZnO nanocomposite as a recyclable catalyst with enhanced reducing capability

[Display omitted] •CuO/ZnO and rGO-CuO/ZnO nanocomposites have been successfully synthesized by simple hydrothermal process.•The XRD, FTIR, confirmed the formation of these nanocomposites and UV–vis study revealed the stepwise growth process.•SEM studies showed the different shaped nanomaterials such as, ‘plate-rod’ and ‘puffed rice ladoo’ like nanostructures depending upon the growing surface used.•Due to high specific surface area the rGO-CuO/ZnO nano catalyst showed about 98 % reduction efficiency of 4-nitroaniline in 10 min.•The rGO-CuO/ZnO nanocomposite also showed a good catalytic reusability with almost remains unchanged. Reduced graphene oxide-CuO/ZnO (rGO-CuO/ZnO) and CuO/ZnO nanocomposites had been synthesized following simple hydrothermal process. Different characterizations such as, X-ray diffraction (XRD), Fourier transform infrared (FTIR) had been investigated to confirm the formation of the nanocomposites and the UV–vis studies revealed the step by step growth mechanism of CuO/ZnO nanocomposite on rGO surface. SEM study showed that different shaped CuO/ZnO nanocomposites grown up depending upon the nucleation surface used. The ternary rGO-CuO/ZnO nanocatalyst exhibited enhanced catalytic activity over the organic dye 4-nitro aniline (4-NA) than that of virgin CuO/ZnO nanocomposite and they also showed good reusability after four cycles. This nanocomposite (rGO-CuO/ZnO) also showed high specific surface area (SSA) due to combine of rGO with CuO/ZnO nanomaterials.