Glowing synthetic chlorohectorite: The luminescent features of a trioctahedral clay mineral

Santos H.S.; Carvalho J.M.; Viinikanoja A.; Hyppanen I.; Laihinen T.; Romani E.C.; Larrude D.G.; Tuominen M.; Laukkanen P.; Swart H.C.; Brito H.F.; Holsa J.; Lastusaari M.

Glowing synthetic chlorohectorite: The luminescent features of a trioctahedral clay mineral

Tipo

Artigo

Data de publicação

2017

Periódico

Journal of Luminescence

Citações (Scopus)

5

Autores

Santos H.S.
Carvalho J.M.
Viinikanoja A.
Hyppanen I.
Laihinen T.
Romani E.C.
Larrude D.G.
Tuominen M.
Laukkanen P.
Swart H.C.
Brito H.F.
Holsa J.
Lastusaari M.

Resumo

© 2017 Elsevier B.V.Clay minerals are versatile materials with numerous industrial applications. Their unique layered structure can act as a host for many optically active species. The synthesis and luminescence properties of chlorohectorite clays are now reported for the first time. The synthesized clays are composed of quasi-circular nanoparticles with diameters around 20–30 nm showing blue/green emission and persistent luminescence with a duration of ca. 5 s. The luminescence features are associated with titanium impurities in the chlorohectorite structure. It is shown that Ti can act as activator ion even at low concentrations: the XRF and ICP-MS measurements of the chlorohectorite materials indicate a Ti concentration around 60 ppm originating from the precursors. The XPS measurements of the clay materials showed the Ti 2p3/2 signals at 457.8 and 458.9 eV associated with Ti3+ and TiIV, respectively. The excitation spectra confirm Ti3+ as the luminescent center in the chlorohectorites through the bands at 287 and 370 nm, related to the e−(O2−(2p))→TiIV charge transfer and the electronic transitions from the t2g to eg levels of Ti3+, respectively. The persistent luminescence properties are due to structural defects common for layered silicates.

Assuntos Scopus

Chlorohectorites , Electronic transition , Excitation spectrum , Layered silicate , Luminescence properties , Luminescent centers , Persistent luminescence , Traps