Morphological and sensing properties of electrochemically deposited ZrO₂ layers

The ZrO₂ is an increasingly used material for various applications in different fields such as optoelectronics, medicine and environmental monitoring. Its main advantages are due to almost unique properties, such as high mechanical and thermal resistances, high dielectric constant and refractive index, wide range of optical transparency and capability for diverse nanostructuring.

Among different methods applied for synthesis of metal-oxide nanostructures, the electrochemical deposition is an attractive method – it is cost-effective, environmentally compatible, requires relatively simple apparatus and offers easy control of morphology of produced nanostructures by varying the deposition parameters.

The aim of our work is to study the morphological and sensing properties of nanostructured ZrO₂ layers, electrochemically deposited on the gold electrodes of AT-cut quartz resonators. The deposition is carried out in aqueous solution containing 5 mM of ZrOCl₂ and 100 mM of KCl. The layers sensing abilities towards ammonia and ethanol vapors are measured by using Quartz Crystal Microbalance (QCM) method. The influence of electrodeposition conditions (the temperature and time) on layers morphology and sensing characteristics is measured and analyzed.

The layers morphology significantly depends on deposition temperature that leads to nanostructured grains with different size, shape, surface density, and roughness. The results for gas sensing show low sensitivity to ethanol and high sensitivity to ammonia. As a whole, the work confirms the suitability of ZrO₂ electrochemical deposition for the further design and development of QCM gas sensing devices.