*4.1. Mechanical Synthesis*

This technique is used to realize nanosheets with a fairly large surface/volume ratio. Adhesive tapes are capable of detaching thin strips of BP, which are then returned to the SiO2-based substrate. To eliminate residues released by the adhesive, BP strips are heated up to 180 ◦C. Although this technique guarantees the synthesis of highly pure BP nanosheets, currently, it is not seen as optimal; in fact, BP produced with this technique does not necessarily demonstrate the same thicknesses of layers. Alternative techniques have been investigated using polymers synthesized and formed at specific temperatures [23].
