Open AccessFunctionalization of titanium dioxide through dye-sensitizing method utilizing red amaranth extract for phenol photodegradation
Author(s) -
Yehezkiel Steven Kurniawan,
K. Anggraeni,
Renny Indrawati,
Leny Yuliati
Publication year - 2020
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/902/1/012029
Subject(s) - photodegradation , titanium dioxide , photocatalysis , nuclear chemistry , fourier transform infrared spectroscopy , amaranth , pigment , visible spectrum , photochemistry , phenol , absorption (acoustics) , chemistry , materials science , surface modification , organic chemistry , chemical engineering , catalysis , food science , optoelectronics , engineering , composite material , metallurgy
In this work, red amaranth (RA) extract was utilized as the source of the natural pigments for dye-sensitizing of the TiO 2 . The natural pigments were isolated from the RA leaves through a maceration technique to obtain the RA extract as a red powder. Since photocatalytic efficiency of titanium dioxide (TiO 2 ) under visible light is negligible, further modification such as by addition of dye-sensitizer is required. The TiO 2 was sensitized using the natural pigments contained in the RA extract using (3-aminopropyl)trimethoxysilane (APTMS) as the linker agent through an impregnation method to give the dye-sensitized TiO 2 composite (RA-APTMS/TiO 2 ). After dye-sensitizing, new absorption peaks at 1632–1030 cm −1 were detected in the Fourier transform infrared (FTIR) spectra, which were corresponded to the functional groups of chlorophyll originated from the RA extract. Furthermore, the appearance of a new absorption peak at 665 nm in the diffuse reflectance ultraviolet-visible (DR UV-vis) spectra also supported the successful sensitization of the TiO 2 by the RA extract. Photocatalytic tests showed that while the unmodified TiO 2 could not degrade phenol under visible light, the RA-APTMS/TiO 2 composites exhibited photodegradation ability in 9, 13, 22 and 7 % when using 5, 10, 20 and 30 % mass ratio of the RA extract, respectively.