Abstract The present study reports an economical and environmentally friendly technique for the synthesis of zinc oxide nanoparticles. The water extract of Averrhoa bilimbi (L) fruit was used in this one-pot synthesis approach for ZnO nanoparticle reduction and stabilisation. Varied size, shape and properties of the synthesized nanomaterials were obtained by tuning the pH of the synthesis medium. X-ray diffraction techniques, diffuse reflectance spectroscopy, photoluminescence and scanning electron microscopy analysis were used for characterizing phytochemical capped ZnO nanoparticles. The morphological change with varying pH was observed from scanning electron microscopy images. Short duration of synthesis with high yield product at ambient room temperature are the salient features of this procedure. The synthesised ZnO nanoparticles showed excellent photocatalytic activity and superhydrophilicity to be used in a wide range of applications.