1. Milling: This involves mechanical grinding of bulk materials to produce finer particles. For instance, ball milling is commonly used to produce nanoparticles of catalysts. 2. Lithography: Techniques such as photolithography and electron beam lithography are used to create precise patterns on a substrate, which can then be used to develop catalytic surfaces. 3. Etching: Both chemical and physical etching methods are employed to create nanoscale features on a catalyst's surface, enhancing its surface area and thereby its activity.
