Zinc oxide functionalized human hair: A potential water decontaminating agent

Abstract

Hypothesis Nano-ZnO is an efficient photocatalyst that can be employed for water purification but its separation from water is difficult. Immobilization of nano-ZnO on a fibrous material is expected to add practicality to its application. Experiments We synthesized ZnO nanostructures on a natural waste, human hair, via a cost-effective process, characterized the system and tested the efficacy of the composite for photo-decomposition of a few toxic materials in water. Findings Layers of well crystalline ZnO nanostructures grew homogeneously on hair strands, initially as thin plates that slowly turned with time into nanorods (length 400–600 nm, width 28–30 nm), converting the mildly hydrophobic hair (water contact angle 104°) surface into superhydrophobic (water contact angle 149°). The composite was found to effectively photodecompose toxic dyes like methylene blue, direct red, alizarin red S and aromatics (toluene), for multiple cycles without losing much efficacy.