Vapor-Phase Techniques

We are utilizing the Vapor-Liquid-Solid (VLS) technique to synthesize one-dimensional (1D) metal oxide nanowires. The VLS technique involves a three-step mechanism: (i) vapor phase precursor decomposition, (ii) dissolution of the precursor in a liquid catalyst droplet, and (iii) solidification of the dissolved species into 1D structures on a suitable substrate. Through optimizing the selection catalyst material, precursor, and growth conditions, we have achieved various morphologies, crystal structures, and compositions in the resulting metal oxide nanowires, such as ZnO, SnO2, CuO, Bi2O3, NiO, NiO-GDC, NiO/ZnO heterojunction, and NiO/NiWO4/WO3 (p–p–n) nanowire heterostructures. The prepared 1D materials have shown promising results in applications such as gas sensors and solid oxide fuel cells.

Thermal Oxidation

After preparing a suitable substrate on which the metal oxide nanowires will grow, a deposition of metallic layer through various methods like physical vapor deposition (PVD) and chemical vapor deposition (CVD) will be placed in a furnace or chamber with a controlled atmosphere of oxygen. Temperature, gas flow rate, and oxidation duration are critical parameters that determine the growth rate and the quality of the resulting nanowires.

Different nanomaterials have been synthetized with this techniques, such as quasi 1D structures of ZnO, CuO, WO3, CO2O3, TiO2 and many more.

Magnetron Sputtering

Magnetron sputtering is a technique to prepare thin films that is easily scalable on the industrial scale. At SENSOR Lab, sputtering is used for deposition of metallic films for thermal oxidation, metal contacts, catalyzer layers, sensing layers (metal oxide semiconductors), buffer layer for fuel cell applications and Transparent Conducting Oxides (TCO). 

The thin films can be deposited on different substrates: alumina, silicon, glass and quartz are the most common used in our lab, but we can also deposit on not conventional substrates, such as paper, plastics and MEMS.

Moreover, thanks to magnetron sputetring we can synthetize decorated and core-shell nanostructures, such as Au@MoO3 and CuO-ZnO Core-Shell. 

We prepare by RF and pulsed DC sputtering different oxides for sensing applications (ZnO, SnO2, In2O3, WO3, MoO3, TiO2, Ga2O3, and several mixed oxides like SnO2-In2O3, TiO2-Fe2O3, WO3-MoO3 and TiO2-WO3). Deposition can be conducted in inert or reactive atmosphere at a substrate temperature in the range 20°C-  800°C.

Electrochemical Anodization

In Progress...

Liquid Phase Techniques

At Sensor Lab, we utilize the precipitation and green synthesis protocols to prepare powdered nanoparticles and composite. These protocols are interestingly becoming popular because of their reusability, economical, sustainable and ecofriendly approach. The structural, morphological and catalytic properties of the synthesized nanostructures can be controlled by adjusting various parameters such as temperature, time, calcination and concentration of the precursors. Hence, we can produce the more efficient nanostructures for the catalytic activity for energy and medical sides.  

In our research we have synthesized various nanostructured materials such as: NiNPs, FeNPs and ZnNPs. Also, nanocomposite materials of CEINP and CENNP have been prepared for hydrogen production by using steam methane reforming (SMR) and thermal cracking. 

Hydrothermal Synthesis

In Progress