Mechanochemical Forces as a Synthetic Tool for Zero- and One-Dimensional Titanium Oxide-Based Nano-photocatalysts

A new field where the utilization of mechanochemistry can create new opportunities is materials chemistry, and, more interestingly, the synthesis of novel nanomaterials. Ball-milling procedures and ultrasonic techniques can be regarded as the most important mechanochemical synthetic tools, since they can act as attractive alternatives to the conventional methods. It is also feasible for the utilization of mechanochemical forces to act synergistically with the conventional synthesis (as a pre-treatment step, or simultaneously during the synthesis) in order to improve the synthetic process and/or the material's desired features. The usage of ultrasound irradiation or ball-milling treatment is found to play a crucial role in controlling and enhancing the structural, morphological, optical, and surface chemistry features that are important for heterogeneous photocatalytic practices. The focus of this article is to collect all the available examples in which the utilization of sonochemistry or ball milling had unique effects as a synthesis tool towards zero- or one-dimensional nanostructures of a semiconductor which is assumed as a benchmark in photocatalysis, titanium dioxide.