TNRs and TNPs were synthesized in a seeded-growth approach following the Gordon method as described in our previous work, 20 with slight modifications. All reactions were carried out in a nitrogen atmosphere using standard Schlenk techniques. Briefly, TNRs were synthesized using TiCl 4 as a precursor, while TNPs were prepared using TiF 4 . In both reactions, OLAM and OLAC were used as surfactant and oxygen source, respectively. First, TNC seeds are formed, followed by the drop-wise addition of a certain amount of precursor, depending on the desired TNC dimensions. The addition rate of the precursor solution during TNC growth was set to 9 mL/h. For the TNRs, the suspension was washed with IPA (1/1, v/v) and centrifuged for 15 min (8000 g, 15 • C). The solid was redispersed in toluene, and the washing step was repeated. The solid was redispersed in 15 mL chloroform, resulting in a clear-yellow solution. For TNP purification, the particles were precipitated with IPA (1/1, v/v) and centrifuged for 15 min (6000 g, 15 • C). The pellet was redispersed in chloroform and the washing step was repeated twice. The blue solid was dispersed in 15 mL chloroform.