Visible light absorption of surface modified TiO2 powders with bidentate benzene derivatives

Abstract

TiO 2 powders with different specific surface area were prepared using reproducible, sol-gel synthetic route and their ability to form hybrids with catechol and 5-amino salicylic acid was compared with the commercially available Degussa P25 TiO 2 powder. Microstructural characterization involving transmission electron microscopy, X-ray diffraction analysis and nitrogen adsorption-desorption isotherms indicated that TiO 2 samples cover reasonably wide size and/or specific surface area range (50-115 m 2 /g). The surface modification of TiO 2 powders with catechol and 5-amino salicylic acid induced significant shift of absorption to the visible spectral region due to charge transfer complex formation. It should be emphasized that tunable optical properties of TiO 2 in powder form have never been reported in the literature. The largest red M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 2 shift of the absorption onset was observed for sample with the largest specific surface area upon surface modification with both ligands. The binding of the modifier molecules to the surface Ti atoms was studied using Fourier transform infrared spectroscopy.

Enhanced Photocatalytic Performance of Surface-Modified TiO2 Nanofibers with Rhodizonic Acid

“…The absorption onset of the TiO 2 /RhA sample is significantly red-shifted in comparison to the pristine TiO 2 NFs due to ICT complex formation, beyond the measured wavelength range (> 800 nm). This result is similar to the reported data in the literature for catecholate-type of ligands [6,7]. The ultraviolet photoelectron spectrum (UPS) of TiO 2 /RhA hybrid (Fig.…”

“…Also, the complete decolorization of MB was achieved over TiO 2 /RhA for ~ 60 min, while over pristine TiO 2 NFs the MB is not fully decomposed after 90 min. The improvement of photocatalytic performance of visible-lightresponsive TiO 2 due to ICT complex formation has been reported in the literature [7,11,12]. However, to the best of our knowledge, the enhanced optical properties of TiO 2 , and consequently enhanced photocatalytic performance was obtained for the first time using non-benzenoid aromatic ligand [13], Rhodizonic acid.…”

“…Recently, a new approach for improvement of optical properties of TiO 2 emerged, based on interfacial charge transfer (ICT) complex formation between surface Ti atoms and colorless organic molecules, mainly benzene derivatives [6][7][8]. The condensation reaction between two hydroxyl groups, one originating from the surface of TiO 2 and the other from the ligand, leads to covalent Ti-O-C linkage.…”

Rare Earth‐Doped Anatase TiO2 Nanoparticles

“…In the method of hydrolysis of TTIP, products are characterized by low surface area, wide pore size distribution with contribution to pores of mesopores scale (<50 nm) [22]. The sol-gel synthesis with a two-step procedure of mixing precursor solutions was successfully used to obtain RE-doped TiO 2 [18,[23][24][25][26][27][28][29][30][31][32][33][34][35][36]. The gels obtained in such procedures undergo various temperature treatments, which are summarized in Table 2.…”

Surface-modified TiO2 nanoparticles with ascorbic acid: Antioxidant properties and efficiency against DNA damage in vitro

“…Also, the appearance of absorption in the visible spectral region has been observed upon surface modification of colloidal TiO2 NPs with ascorbic acid (AA) [25,32]. Primary motive of research in this area has been enhancement of variety of light-driven processes by extension of TiO2 absorption into more practical spectral range [33][34][35][36]. However, electron donating ligands have pronounced radical scavenging ability, and, to the best of our knowledge, antioxidant and antigenotoxic properties of free and bound ligand molecules were never compared.…”