Biotemplate-mediated synthesis of one-dimensional oxides

In the last years researchers have focused their attention in preparation of biomorphic materials with highly ordered morphologies by inexpensive methods as template mediated synthesis. So far, many biological systems... [ view full abstract ]

In the last years researchers have focused their attention in preparation of biomorphic materials with highly ordered morphologies by inexpensive methods as template mediated synthesis. So far, many biological systems (bacteria, virus, butterfly wings, natural fibers) have been used as biotemplates in order to produce inorganic multiscale architectures with different applications: gas sensing, environmental protection, chemical sensors. Nickel oxide is an important semiconductor and antiferromagnetic material, widely used in electrochemical, optical and magnetic applications and its functionality greatly depends on the crystalline phase and its structuring ant nano-and microscale level.

The aim of this work was to prepare biomorphic one-dimensional NiO by using natural fibers as bio-template and to study the effects of the synthesis parameters (type of fiber, calcination temperature, precursor concentration) on their structural and functional properties.

Fig. 1: SEM image of biomorphic NiO produced by using cotton (a), hemp (b) and flax (c) as biotemplates.

The final oxide products were obtained by infiltration of biotemplates (cotton, hemp and flax) with nickel nitrate solution at different concentrations, followed by calcination in air, at various temperatures. The phase formation and morphologies have been investigated by using X-ray diffraction (XRD) and scanning electron microscopy (SEM) (Fig. 1). The influence of the synthesis parameters and templates on the functional characteristics of the 1-D NiO samples was determined and interpreted in terms of their nano/microstructural properties.

Acknowledgements: This work was supported by the Romanian UEFISCDI PN-III-P4-ID-PCE-2016-0817 grant.