Preparation and Ion Diffusion Performance of the Nanoporous TiO₂ Coating through Vacuum Cold Spray

This study investigates the effect of powder size on the porosity and diffusion properties of vacuum cold sprayed TiO₂ coatings. In the experiments, coating samples are produced using powders with different primary particle sizes. Porosity and pore size in the TiO₂ coatings are assessed via nitrogen adsorption and desorption and correlated with the diffusion coefficient of I₃^ֿin acetonitrile. The results show that pore size is significantly influenced by primary particle size, but porosity is the same regardless of the particle size of the powder. The I₃^ֿion diffusion coefficient is shown to increase with increasing pore size and can thus be adjusted through proper selection of the powder feedstock.