Fabrication of environmental-friendly materials using atomic layer deposition

In this article, I will introduce recent developments of environmental-friendly materials fabricated using atomic layer deposition (ALD). Advantages of ALD include fine control of the thin film thickness and formation of a homogeneous thin fim on complex-structured three-dimensional substrates. Such advantages of ALD can be exploited for fabricating environmental- friendly materials. Porous membranes such as anodic aluminum oxide (AAO) can be used as a substrate for TiO₂ coating with a thickness of about 10 nm, and the TiO²-coated AAO can be used as filter of volatile organic compound such as toluene. The unique structural property of AAO in combination with a high adsorption capacity of amorphous TiO₂ can be exploited in this case. TiO₂ can be also deposited on nanodiamonds and Ni powder, which can be used as photocatalyst for degradation of toluene, and CO₂ reforming of methane catalyst, respectively. One can produce structures, in which the substrates are only partially covered by TiO₂ domains, and these structures turns out to be catalytically more active than bare substrates, or complete core-shell structures. We show that the ALD can be widely used not only in the semiconductor industry, but also environmental science.