New Hybrid Properties of TiO2 Nanoparticles Surface Modified With Catecholate Type Ligands

Table 1 Ligands used for modification of TiO₂ nanoparticles, Benesi–Hildebrand binding constants, and bandgaps upon binding

Ligand	K _b(M⁻¹)^a	Bandgap (eV)
Catechol	2490 ± 120	1.96
Pyrogallol	3130 ± 120	1.89
Gallic acid	1700 ± 100	1.92

^a The absorption wavelengths at which the stability constants were determined are 400 nm (catechol), 475 nm (gallic acid), and 425 nm (pyrogallol)