D.C. Manfroi, L.P. Andrade, A.A. Cavalheiro, A.A. Jos, G.F. Teixeira, L.A. Perazolli, J.A. Varela, M.A. Zaghete
Universidade Estadual Paulista, BR
alkali titanates, copper, doppant, photoluminescence, photocatalysis
Alkali titanates have been intensively investigated mostly because of their properties. And the interest for transition metal doping of 1D titanate nanostructures is enormous, especially copper. In the present work we report the synthesis of Cu-doped titanate nanotubes (CuNT) by microwave-assisted hydrothermal method (MWH). TiO2 anatase was used as a precursor and Cu2+ as dopant, the structural, photoluminescence and photocatalytic properties were studied. Through XRD it was observed that Cu doped sodium titanates (CuNT) have similar pattern to layered titanate structure (Na2Ti6O13) single phase. The SEM images of as-synthesized CuNT2 and 4 hours show for both morphologies of 1D nanostructures. All of the CuNT PL spectra show that the nanotubes have the main emission bands at 470–480 nm and a relatively broad shoulder. The emission peak present lower intensity for CuNT4h, indicating the reduction of defects concentration due to longer hydrothermal treatment duration which promote the structure organization.It can be seen that the decolorization efficiency firstly increases for nanotubes copper doped and CuNT4h shows the best photocatalytic activity up to 120 minutes. This sample that presented more photoactivity showed, through PL emission, higher concentration of surface defects that generate intermediate band gaps, with lower energy.