A novel NiO/ZnO biomorphic nanotubes synthesized using human hair template with an enhanced gas sensing for n-butanol

Novel human hair template templated layered ZnO gas-sensing nanotube materials (CT NiO/ZnO) were synthesised by using a simple and low-cost biotemplate approach. X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray Detector（EDS）and Brunauer Emmett Teller (BET) were carried out to characterize the structure and morphology of the materials. The final CT NiO/ZnO composites materials were composed of hexagonal wurtzite ZnO and cubic NiO and exhibited hollow tubular structure. The p-n heterojunctions of the composites formed in the interface of NiO and ZnO. The results of gas sensitivity test indicated that CT NiO/ZnO had the great gas sensitivity (Rair/Rgas=68.82) and selectivity (5-10 times greater response than the other vapors) at 240°C to n-butanol on a gas sensing platform. The enhancement of CT NiO/ZnO’s gas sensing properties were attributed to high concentration of oxygen vacancies and the formation of p-n heterojunctions after the introduce of NiO.