Surface modification of carbon fiber by direct growth of zinc oxide nanowalls using a radio-frequency magnetron sputtering technique

•Low temperature growth method•Zinc oxide nanowall growth on carbon fiber•Microstructural analysis using high resolution electron microscopy•X-ray and electron diffraction analysis•Photoluminescence characteristics

Zinc oxide nanowalls have been grown uniformly on a carbon fiber substrate at room temperature using a radio-frequency magnetron sputtering technique. The synthesis process involved two steps; application of catalyst using a solution process and subsequent radio-frequency sputter deposition of zinc oxide. The nanowalls were examined by field emission scanning electron microscopy for their microstructure and morphology while their nanostructure was studied by high resolution transmission electron microscopy. Both the X-ray and the electron diffraction techniques were used for crystallographic analysis of the produced nanowalls. Selected area electron diffraction and high resolution lattice image showed highly crystalline structure of the nanowalls. Photoluminescence analysis was carried out for the determination of their optical characteristics which showed a strong ultra violet peak at 393 nm and violet peak centered at 401 nm. The latter is a characteristic peak of zinc oxide which demonstrates oxygen rich composition of nanowalls.