Fabrication of hierarchical ZnO nanostructures on cotton fabric for wearable device applications

Highlights: • A simple preparation of ZnO nanostructures coated on cotton fibers was proposed. • ZnO nanostructured coated cotton fibers exhibit excellent UV protection properties of the value is 183.84. • The ZnO cotton fabrics show significant near super-hydrophobic properties. • The ZnO nanostructures endowed fibers shows the 0.02 Ω-cm of low resistivity. • Higher power factor of 22 μW/m K² was obtained. - Abstract: We have investigated ZnO nanostructures on cotton fabric (CF) s a flexible material for an application of wearable thermoelectric (TE) power generator which requires super-hydrophobicity, UV protection, and high TE efficiency. Field emission scanning electron microscopy images revealed that the formed ZnO nanostructures have a mixture of nanorods and nanosheets and are uniformly coated on the CF. XRD pattern and Raman spectra revealed that the ZnO nanostructure has a wurtzite structure. Contact angle measurements showed that the ZnO-nanostructures-coated CF possessed a high super hydrophobic nature with an angle of 132.5°. ZnO nanocomposite/CF sample exhibited an excellent UV protection factor 183.84. Seebeck coefficient, electrical resistivity and thermoelectric power factor of the ZnO nanostructures on cotton fabric were evaluated to be 28 μV/K, 0.04 Ω-cm, and 22 μW/m K², respectively.